High Energy Ignition (HEI)

[content22207]

Some selected posts from another thread, just to get this thread started:


I know several owners, myself included, who are running true HEI with excellent results.

Bear in mind that ignition coil secondary voltage is directly proportional to its input. You can not run only 6-8 volts into a high winding coil and expect anything close maximum rated output (most HEI coils are rated at 12-14 volts input). You will get more secondary voltage than a stock Bosch coil simply by virtue of the higher number of windings, but certainly not anything close to 40,000 volts.

Bill Robertson
#5939


Are you running 12v to the coil with the stock Bosch amp or the Duraspark you were running? I know guys run 12v to the Duraspark all the time.


I am running 12.5 volts into a Pertronix coil. Voltage is something like 8 or 9 volts to the Bosch ECU at the other end. I was only test driving a Duraspark unit for Byrne. He gave me his dead Bosch unit, which I will use to make another adapter to carry with me in case my ECU dies.

My resistor grid is wired in parallel (that is how I get 12.5 volts into the coil):
4258
Pertronix coils can of course handle full charging voltage no problem. I only step it down for the ECU's benefit. I don't trust Bosch ECU's any further than I could throw one of the damn things. If I was running an original Ford Aerospace Duraspark ECU, I wouldn't reduce input voltage at all.

The biggest advantage of HEI is the ability to open up the plug gap. .026" is ridiculously small. No wonder stock DeLoreans run like crap. The benefits of wider plug gaps have been known for decades. Nearly every other manufacturer was already running .05" plug gaps when DeLoreans were new in the showroom. GM introduced HEI in 1971. DeLorean ignition was obsolete even before these stupid little cars were nothing more than a stainless steel fantasy in the back of JZD's mind. The man was vice president of the company that pioneered HEI, for crying out loud -- he should have known better.

Speaking of which: DO NOT OPEN YOUR PLUG GAP IF YOU ARE STILL RUNNING SUBSTANDARD DELOREAN 6-8 VOLTS INTO THE COIL, NO MATTER WHAT KIND OF COIL IT IS (can I hear an "Amen" Steve?). The stock resistor grid is really better suited for breaker points than breakerless ignition.

Bill Robertson
#5939

You can get away with smaller plug gaps in high compression and forced induction engines because the mixture is easier to ignite. Some owners claim that larger plug gaps are actually counter productive in those circumstances.

In a low compression engine, like the stock DeLorean PRV, the mixture is harder to ignite. Leaning the mixture out for fuel economy and emissions exacerbates the situation. That is one reason American manufacturers were so quick to adopt HEI in the early 70's.

A Society of Automotive Engineers' study from the time: http://dmctalk.org/showthread.php?652-Running-a-DeLorean-on-Ford-Ignition&p=7222&viewfull=1#post7222
I found it particularly fascinating that wider plug gaps also yielded benefits similar to increased gap projection (you don't need to change spark plug length -- just open the gap up).

Bill Robertson
#5939


Regardless of everyone's position on the stock vs. modified coil/ignition, everyone should at least agree that the stock plug gap is pretty small.

As the years went on every car manufacturer has found a way to increase secondary voltage and with it the plug gap.

A stock system works well. That has been proven through millions of real-world miles cars with a similar setup have put on the road. What I don't understand is why a car company would base their 'new' electronic ignition around the use of an off-the-shelf coil. If they were putting the money into developing this new system why not develop a new a new coil to take advantage of the breakerless ignition?

Bosch wasn't the only one to do this. Ford did the same thing over here. I just don't understand why they would stop at 6-8v at the coil. They knew in the 60's that increased primary voltage was the way to go for performance and economy. They wouldn't have resorted to dual-point distributors (and the associated headaches) if they didn't.


In the 1970's Ford used 10.5 volts primary (Duraspark breakerless ignition). Plug gaps were .044".

Bill Robertson
#5939


Here's where I found the info I was basing my statement:

http://www.autozone.com/autozone/repairguides/Ford-Ranger-Bronco-II-1983-1990-Repair-Guide/DISTRIBUTOR-IGNITION/Dura-Spark-II-Ignition-System/_/P-0900c15280077d43

From the above troubleshooting guide:
"If no spark occurs, measure the voltage on the battery side of the coil.

Less than 6 volts - Repair the wire carrying current to the battery terminal of the coil and repeat test.

If voltage is 6-8 volts - Substitute, but do not install, a known good module and repeat the test. If spark then occurs, reconnect the original module to verify its being defective. Replace as required. Refer to step 10 if the battery voltage is present."

This is not a Ford document FWIW.

[content22207]

1978 Lincoln, stock wiring before the coil (Duraspark ECU):
4291

Bill Robertson
#5939

[content22207]

From another thread:


All too often someone gets the idea that bolting in a new, different part will give them better performance, gas mileage, reliability, <blank> etc. You can fill in the blanks. If it was that easy the original manufacturer would have done it. In some cases they actually do see some improvement only because the part they replaced was old, worn, the wrong one, or defective. There is little if anything to be gained by putting "performance" parts into the ignition system. If every part you could bolt on to the car added the performance each claimed you could theoretically double the HP of the car. Who is going to believe THAT! A BIG problem with deviating from stock is that it becomes near impossible for anyone to help when the car has a problem. Too many variables and no good place to start troubleshooting. For a street driven car reliability is very important. To a big extant more important than a small, temporary increase in performance. Another thing to remember is most systems are like chains. Only as strong as the weakest link meaning if you don't improve the WHOLE system, improving one part of it does not improve what the whole system can do. As Martin said, "Show Me!" Put it on a dyno and show the numbers. Till then it is just a pretty and expensive part. I swear that my car always runs better after I clean it or change the oil. A very subjective effect. After spending money on a performance part you expect the car to run better, faster, etc!
David Teitelbaum

Bullshit.

Bill Robertson
#5939

It never ceases to amaze me that a small, but supposedly "guru," contingent of this community close their eyes, stick their fingers in their ears, and shout "la la la, I'm not listening" as loud as they can whenever the subject of DeLorean ignition comes up.

In 1972, the Society of Automotive Engineers determined that ignition with higher secondary voltage, larger plug gaps, and longer spark duration improved combustion. "La la la. I'm not listening."

Nearly every car manufacturer (ie: Ford, General Motors, Chrysler, Datsun, Honda, Toyota, Subaru, Mazda, et al) started installing ignitions with higher secondary voltage, larger plug gaps, and longer spark duration in the early 1970's, and has never gone back to earlier spec ignition since. "La la la, I'm not listening."

High voltage coils cost half as much as low voltage Bosch coils. "La la la, I'm not listening."

The very cars DeLoreans were supposed to compete within 1981 had already been running HEI for years (DeLorean ignition was out of date new on the showroom floor). "La la la, I'm not listening."

Excuse me for a moment while I pick up the eyeballs that just rolled clear out of my head.

Bill Robertson
#5939


... What I don't understand is why a car company would base their 'new' electronic ignition around the use of an off-the-shelf coil. If they were putting the money into developing this new system why not develop a new a new coil to take advantage of the breakerless ignition?...

Something just occurred to me: AM radio may have been the limiting factor. AM frequencies are very liable to ignition interference. On my own cars it shows up as a distinctive "tick tick" at idle, rev'ing to a continuous static hum. I'm pretty sure Europeans listened to a lot of AM radio in the 1970's. Bosch igntion may well be designed not for combustion efficiency, but rather not to interfere with AM radio reception. How else do you explain the resistor in our rotor buttons....

Bill Robertson
#5939

[Farrar]

I have always reasoned that DeLoreans have the ignition systems they do because it was quick and cheap to simply take the PRV lock, stock, and barrel from another application and drop it in. Everything I have learned about these cars suggests to me that if they had simply had more time they could have had a better product, but time was against them so we got what we got. I wouldn't be surprised to find Peugeot, Renault, and Volvos of the late 1970s using the PRV V6 to have the exact same ignition setup -- in fact, I'd expect it.

Farrar

[content22207]

Volvos do. Even the ECU is identical (helpful hint if anyone has the opportunity to scavenge a spare from a junkyard).

Bill Robertson
#5939

[content22207]

*sigh*. No, I'm asking you to prove that with your ignition modification, you achieved anything more than could be achieved with new stock components.

My ignition is now 1981 Mustang caliber. Combined with its Mustang carburetor, #5939 is exactly 37.615% faster than a factory spec DeLorean (even with new components).

Bill Robertson
#5939

[stevedmc]

My ignition is now 1981 Mustang caliber. Combined with its Mustang carburetor, #5939 is exactly 37.615% faster than a factory spec DeLorean (even with new components).

Bill Robertson
#5939

Have you ever taken #5939 up to speed? I brought 16510 up to 105 mph but got scared and slowed down since my tires are only rated for 108 mph.

[Farrar]

Didn't you once say that your engine might have slightly different cams because it was originally intended for stationary use? I would add that to your list of deviations from stock DeLorean trim, if so.

Won't matter anyway -- Martin won't believe anything without a dyno printout.

What's the deal, anyway? Martin's happy with his car, and you're happy with yours.

Farrar

[content22207]

Have you ever taken #5939 up to speed? I brought 16510 up to 105 mph but got scared and slowed down since my tires are only rated for 108 mph.

I still have a speeding ticket on my insurance, and now am CDL for the church, so I stick to 5 MPH over.

Plus I would be a little self conscious to see helicopter coverage of my performance modified little silver car embarrassing pursuing North Carolina troopers on national news.

Bill Robertson
#5939

[content22207]

Didn't you once say that your engine might have slightly different cams because it was originally intended for stationary use? I would add that to your list of deviations from stock DeLorean trim, if so.

Test driving carb conversions, and comparing their seat of pants performance to final installation on other cars, has led me to doubt that earlier suspicion.

My manifold does move more air than either a K-Jet manifold or fabricated manifolds because its runners have square cross sections, not round. I also have a big central plenum common to all cylinders (single plane) rather than a dual plane design. The combined effect is to move my power band towards higher RPM's, which anyone who has ridden with me can confirm I reach very quickly.

As soon as I capture and edit down a short segment of video, I will post visual evidence that my car is faster than a stock DeLorean.

Bill Robertson
#5939

[sean]

I think Martin's beef is Bill's willingness to share his happiness that has only been tested on his car, and maybe a few other , for a relatively short amount of time then claim outstanding results from his personal use as hard tested facts.

[Ron]

All too often someone gets the idea that bolting in a new, different part will give them better performance, gas mileage, reliability, <blank> etc. You can fill in the blanks. If it was that easy the original manufacturer would have done it. In some cases they actually do see some improvement only because the part they replaced was old, worn, the wrong one, or defective. There is little if anything to be gained by putting "performance" parts into the ignition system. If every part you could bolt on to the car added the performance each claimed you could theoretically double the HP of the car. Who is going to believe THAT! A BIG problem with deviating from stock is that it becomes near impossible for anyone to help when the car has a problem. Too many variables and no good place to start troubleshooting. For a street driven car reliability is very important. To a big extant more important than a small, temporary increase in performance. Another thing to remember is most systems are like chains. Only as strong as the weakest link meaning if you don't improve the WHOLE system, improving one part of it does not improve what the whole system can do. As Martin said, "Show Me!" Put it on a dyno and show the numbers. Till then it is just a pretty and expensive part. I swear that my car always runs better after I clean it or change the oil. A very subjective effect. After spending money on a performance part you expect the car to run better, faster, etc!
David Teitelbaum+1
100%


You will get a small performance boost. High winding coils produce more secondary voltage than low winding coils can from the exact same input voltage.

Bill Robertson
#5939
I agree with the others -- Not by changing out a good stock coil alone. The stock coil can supply all the energy the stock plugs need to fire correctly. The perfect coil will only produce enough energy to fire the plug, no matter how many gazillawatts it has "in reserve".

Now if you changed other things, like the plug gap, plug itself, cap-rotor gap, button resistance, etc. you may have stumbled on a combination that performs better and I too would like to see it -- strictly ignition mods, not what you had to do to your carb setup to get it all where you liked it (another interesting story).

[content22207]

http://www.youtube.com/watch?v=1MjA4R6t1Fs

Bill Robertson
#5939

[sean]

http://www.youtube.com/watch?v=1MjA4R6t1Fs

Bill Robertson
#5939

....:ehh::question:

Ok, this video shows us that one car paced traffic and another didn't. I wouldn't hold your breath on Mythbusters to come a knocking as an adviser on how to test and compare things. Now these guys may :D:


http://www.youtube.com/watch?v=iZhEcRrMA-M

[Soundkillr]

....:ehh::question:

Ok, this video shows us that one car paced traffic and another didn't. I wouldn't hold your breath on Mythbusters to come a knocking as an adviser on how to test and compare things.

Oh boy, that is a stretch. So the delorean with the camera cant even outrun the truck next to it going 35? Agreed, the camera car isnt even trying.

[content22207]

I simply asked a simple question: of the two DeLoreans in that film clip, which one accelerated faster -- the one in front or the one in back?

This isn't a hard question boys. Even if you make a blind guess, you have a 50% chance of getting the correct answer.

Bill Robertson
#5939

[sean]

I simply asked a simple question: of the two DeLoreans in that film clip, which one accelerated faster -- the one in front or the one in back?

And this is telling us what? The guy in the back chose not to accelerate? The guy in the back is in a sluggish automatic? The guy in the back is running on solar power?

[Soundkillr]

I simply asked a simple question: of the two DeLoreans in that film clip, which one accelerated faster -- the one in front or the one in back?

This isn't a hard question boys. Even if you make a blind guess, you have a 50% chance of getting the correct answer.

Bill Robertson
#5939
Bill, who cares if they were not engaged in a power contest. Which one slowed faster, or had better fuel economy in that film? Who cares, its not relevant. If the lead car passed a viper does that mean its faster. Even if the viper was parked?

[content22207]

Nobody's trying to prove anything -- I just asked a simple question: of the two DeLoreans in that film clip, which one accelerated faster?

If you don't know, at least guess.

Bill Robertson
#5939

[Soundkillr]

Nobody's trying to prove anything -- I just asked a simple question: of the two DeLoreans in that film clip, which one accelerated faster?

If you don't know, at least guess.

Bill Robertson
#5939

what about my questions? Will they go unanswered? How will I ever sleep tonight?

[stevedmc]

Nobody's trying to prove anything -- I just asked a simple question: of the two DeLoreans in that film clip, which one accelerated faster?

Bill's

[Nicholas R]

I'm pretty sure the only way to have test 2 cars in this fashion is to actually call up the Stig and have him drive both for time trials. Until then, the video means nothing.

[Farrar]

If the car in back accelerated faster than the car in front, the car in front would have been rear-ended.

Good thing Bill's car was in front, I guess. :lol:

Farrar

[content22207]

http://www.youtube.com/watch?v=mdboKxsONnQ

Bill Robertson
#5939

[Farrar]

Idea for DCS 2012: drag-racing against Bill Robertson.

Farrar

[stevedmc]

I'm pretty sure the only way to have test 2 cars in this fashion is to actually call up the Stig and have him drive both for time trials. Until then, the video means nothing.

The video proves that Bill's car was accelerating faster than the Delorean behind it. Did you notice the driver zoomed in with the camera instead of speeding up to get closer?

The video doesn't prove that Bill's car is faster, it proves it was moving faster. There are various reasons as to why it was moving faster which could be anything from the driver or the car iteself.

[content22207]

There are various reasons as to why it was moving faster which could be anything from the driver or the car iteself.

Or both.

Does Bill's car + Bill driver = toasted stock DeLorean cheese?

Bill Robertson
#5939

[Farrar]

Mmmm..... toasted cheese.....

http://grilledcheesesandwich.org/wp-content/uploads/2009/07/grilledcheese.jpg

[Bitsyncmaster]

What we need at DCS-12 is a dyno. But my priority is reliability and not increased power. Now if the changes increase MPH then I'm all for that.

[stevedmc]

Or both.

Does Bill's car + Bill driver = toasted stock DeLorean cheese?

Bill Robertson
#5939

Very true. You could have all the performance mods in the world and the car wouldn't go faster if the driver never pressed the gas pedal.

This is slightly off topic but have you ever noticed people in huge pickup trucks, SUVs, and even Hummers that slowly crawl over speed bumps? I have never understood that, expecially with Hummers. These people drive in freaking all terrain vehicles and are worried about some puny little bump messing up their Hummer! When I am in the Delorean I do slow down for speed bumps but when I am in the Geo Metro I show no mercy to speed bumps.

[AdmiralSenn]

At the risk of feeding the fire (and because I have a genuine interest in the topic) I switched to HEI when I first worked on the car. I had done a tune-up previously but the car was still acting funny, so I switched to a Blaster 2 and widened the plug gaps (I was already running MSD wires).

I can't say if it made a huge difference in performance as the car was still acting funny but it certainly helped it start faster. Combined with a new starter, the car usually fires before it even turns over a full revolution. Even with the old starter, the ignition improvement significantly shortened the number of turns before the engine caught.

I am running an MSD-specific ballast resistor instead of the factory setup, as the datasheet for my coil specified using it if there was a resistor in the car originally.

[David T]

Everyone seems to be overlooking the fact that messing with the ignition system has an effect on emissions. It may not matter to any of us now but DMC had to make an engine package that was certifiable by the US EPA. To do that required intense testing with a certain configuration of components. Once certified that configuration was "set in stone" and couldn't be changed easily and without more testing. There is another factor. 30 years later we know some things we didn't know then and there are things available now that weren't back then. For instance the stuff they call gasoline thesedays. There are also performance parts. Anyway there is some potential for improvement in the ignition system but you have to experiment and hit on the right combination and then you have to fine tune it so it will stay in tune for an extended period. As an example, spark plug gaps change over time. Comparing Bill's car to other Deloreans is difficult with all of the modifications he has done to his car. A dyno would be a good, objective test with the least amount of variables. Dyno time costs money. Put your money where your mouth is, I say. Seat-of-the-pants testing is too subjective and is meaningless.
David Teitelbaum

[content22207]

Everyone seems to be overlooking the fact that messing with the ignition system has an effect on emissions.

According to the Society of Automotive Engineers, increasing secondary voltage and widening the plug gap (and lengthening spark duration) "reduce the cyclic combustion variation and the unburned HC."

Does anybody bother the read the scientific studies I post, or do you all reflexively stick your heads in the ground and cry "don't mess with John DeLorean's masterpiece!"

You all are laboring under the mistaken impression that DeLorean ignition was optimized. It wasn't. It was good enough -- that's it. There is plenty of room for improvement, if only to bring it up to 1981 Mustang standards.

Bill Robertson
#5939


I am running an MSD-specific ballast resistor instead of the factory setup, as the datasheet for my coil specified using it if there was a resistor in the car originally.

Go back and re-read the instructions carefully -- it is possible your coil handle full charging voltage (the Bosch ECU, however, is a different story, although mine is handling whatever comes out the far side of 12.5 primary OK).

This is a Pertronix coil on my 1969 Lincoln engine (transplanted into a 1979 vehicle):
4380
Primary voltage is only 12.5 because the engine is idling about 600 RPM -- it'll jump up to 13.8 when rev'ed.

Bill Robertson
#5939

[AdmiralSenn]

Go back and re-read the instructions carefully -- it is possible your coil handle full charging voltage (the Bosch ECU, however, is a different story, although mine is handling whatever comes out the far side of 12.5 primary OK).

This is a Pertronix coil on my 1969 Lincoln engine (transplanted into a 1979 vehicle):
4380
Primary voltage is only 12.5 because the engine is idling about 600 RPM -- it'll jump up to 13.8 when rev'ed.

Bill Robertson
#5939

I'm sure it will handle it - in fact I ran the car for a few weeks that way before I found that line in the directions, and nothing bad happened. But I figured that it really isn't hurting anything and the part was cheap enough that I was happier following the manufacturer's directions.

Maybe if/when I switch to controlling spark through my MS ECU I might drop the extra resistor but the worst consequence of installing it is a blistered fingertip from when I poked it by mistake.

[content22207]

What is your primary voltage? My DeLorean runs .25 ohms of resistance, which knocks the primary side down to 12.5 volts when charging (10-11 volts while cranking IIRC). As stated, my Bosch ECU hasn't had any problems with that yet. Of course a Pertronix coil must have more internal resistance than a Bosch coil simply due to the increased number of windings, so the ECU may be seeing similar voltage on the far side.

Bill Robertson
#5939

[AdmiralSenn]

I have no idea off the top of my head, honestly. I'd measure it but without battery cables it's a little hard to start the car. :wrenchin:

I do know that the last time I checked voltage at the coil it was lower than it should have been, something like 10.6 volts, but given the issues I'm correcting with the wiring, that number is artificially low. I don't remember what it was prior to the resistor but it wasn't much higher.

I think the resistor I have is .8 ohms. When my battery cables get here and I rewire the car I'll be able to measure it again, and it'll be accurate this time.

[DCUK Martin]

I've actually never argued that Bill's car isn't faster than a stock DeLorean. It almost certainly is. The Alpine GTA Atmo with slightly different cams, ignition timing (advance weights) and a twin Solex carb setup but otherwise identical transmission and ignition systems is a heap quicker than a DeLorean - 156hp IIRC. They didn't have the mpg or emissions figures to hit that DMC did. I'm pretty sure Bill's current setup wouldn't meet those either.

My beef is Bill's claims that any of his mods are "better" without qualifying, in accurate specific terminology why. ("Because Ford used it for years" doesn't count).



I agree with the others -- Not by changing out a good stock coil alone. The stock coil can supply all the energy the stock plugs need to fire correctly. The perfect coil will only produce enough energy to fire the plug, no matter how many gazillawatts it has "in reserve".

And *that* is my single reason for doubting Bill's many claims. I experienced many a headache trying to get my turbo engines to ignite properly under boost and the only coil that'd do it was a stock one. The plugs were changed for NGK BP7EFVS's which are a cold plug used by the GTA boys. HT leads were correct Bougicords (the dizzy cap has different connectors than the DeLorean).

Bill's crowing about better coils means nothing without taking the performance to the point where it fails. Anything up to that point will work fine, but won't actually be any better than a properly working stock system in an engine being accurately fuelled. I add this last caveat because in a rich-running engine, a hotter spark will ignite the mixture more readily, but that doesn't make the ignition system "better".

[content22207]

Bill's crowing about better coils means nothing without taking the performance to the point where it fails. Anything up to that point will work fine, but won't actually be any better than a properly working stock system in an engine being accurately fuelled. I add this last caveat because in a rich-running engine, a hotter spark will ignite the mixture more readily, but that doesn't make the ignition system "better".

Obviously you haven't bothered to read the SAE paper I posted. They proved that increased spark energy ignited LEAN mixtures better.

You stick with your chicken bones and tea leaves -- I'm going with the scientists.

Bill Robertson
#5939

[DCUK Martin]

No I didn't bother wading through the link you posted because on the occasions I have bothered I usually discover that you mis-read or misunderstood it anyway. Let's call it a less-than-optimum mixture condition then.

So you'd fix a lean-running engine by fitting "better" ignition?

I really wish you would "go with the scientists". We wouldn't argue anything like as much.

[content22207]

That paper was published on the eve of widescale HEI adoption over here. In its historical context, manufacturers for the North American market were just beginning to adopt leaner fuel mixtures. It is no accident that HEI caught on like wildfire.

Compared to nearly every one of its North American contemporaries, DeLorean ignition specs are woefully out of date. Both coil voltage and spark plug gap more closely resemble 1971 practice than 1981 practice.

Bottom line: the ignition system used by DeLorean is quite badly matched to its lean mixing fuel system.

That is not mere opinion -- it is SAE research, vetted by Lucas, Ford, and Champion Spark Plugs, and historical comparison of DeLorean against all of its North American contemporaries.

Bill Robertson
#5939


No I didn't bother wading through the link you posted because on the occasions I have bothered I usually discover that you mis-read or misunderstood it anyway. Let's call it a less-than-optimum mixture condition then.


Authors' [AC Delco engineers] conclusions, found on page 60 (14th page of the scan):

"The conclusions reached as a result of this investigation are summarized below. Even though these conclusions are based on tests obtained with one basic engine, the trends observed should be similar to what would be expected of all modern engines.
1) The cyclic work measurement, in conjunction with measurement of emission levels, provides one satisfactory method for evaluating engine performance.
2) Extended gap locations, wider gap size, and higher spark energy levels [my emphasis] are the most significant parameters that reduce cyclic combustion variation and unburned HC. Smaller electrode side shows similar effects, but these effects are less pronounced.
..."

The rest of the paper is just boring data that verifies the above, and commentary from Lucas, Ford, and Champion Spark Plug agreeing with the authors' findings.

Bill Robertson
#5939

[DCUK Martin]

Compared to nearly every one of its North American contemporaries, DeLorean ignition specs are woefully out of date. Both coil voltage and spark plug gap more closely resemble 1971 practice than 1981 practice.


Once AGAIN, the voltage does not tell you the whole story. By widening your plug gap, you require a higher voltage to ionise the gases in the gap, but the energy transferred by the spark then depends on the sum of the current (the integral of the graph) the coil drew whilst charging.

And yet another sweeping statement about the age of the "practice". Show me spec on current production cars and their plug gaps from today? 0.7mm is still pretty vanilla flavoured AFAIK.

I haven't read your documentation, but a huge amount of work has gone into improving air-fuel mixing. This is one of the principle reasons behind fuel injection in the first place - more accurate delivery and better fuel atomisation, at which point you need less spark energy to produce a consistent flame front. I'm not an expert on this but it has just struck me that we're probably talking different requirements: With a carburetor, the engine is more likely to need extra spark energy (even though the carb'd PRVs natively used the same ignition as a stock DeLorean).



Bottom line: the ignition system used by DeLorean is quite badly matched to its lean mixing fuel system.


WRONG Working correctly, the DeLorean fuel system works at precise stochiometry (required for the 3-way catalyst to function correctly) unless the driver applies full throttle, at which point it runs rich.

[content22207]

And yet another sweeping statement about the age of the "practice". Show me spec on current production cars and their plug gaps from today? 0.7mm is still pretty vanilla flavoured AFAIK.

Do not compare a 1981 DeLorean to a 2011 model anything -- compare it to its contemporaries: http://dmctalk.org/showthread.php?1405-DeLorean-Spark-Plug-Gap-Compared-To-Other-1981-Cars

Can you spot the cars running Bosch ignitions?

Face it: compared to nearly every other car new on a showroom floor in 1981, DeLorean ignition was woefully dated.

It hasn't improved with the passage of time.

Bill Robertson
#5939

[DCUK Martin]

Face it: compared to nearly every other car new on a showroom floor in 1981, DeLorean ignition was woefully dated.

"Woefully dated" is typical of your exaggerated soap-box antics. If it's reliable and does the job it was designed for, how can it possible be "woeful"?

You can't have it both ways. Either plug gap is a sign of how "modern" the ignition system is, or it isn't. The DeLorean is in line with contemporary european systems of the time (see the German manufacturers quoted in your list, and pointed out by the only reply on that thread) and is in a similar ballpark to modern systems now.

Face this: The DeLorean engine as designed is very reliable and does not suffer disproportionately from ignition system issues. Changing the ignition system is not going to give you any advantages over a properly working original system. You MAY see some advantages to HEI and larger plug gaps but only if you

a) are replacing worn out original components
b) i) have an existing problem which a hotter spark can help mask or
ii) a carburetor which doesn't achieve as good fuel-air mixing as fuel injection

[content22207]

Bullshit.

I will make two more spark gap comparison lists for you -- one for 1969, and one for 2010. That should settle the issue.

Quick Google search (complete lists will require some research on a parts house computer):
- 1969 Mustang with 250 I6: .024-.026"
- 2010 Mustang with 3.7 V6: .048-.052"

- 1969 Camaro with 230 I6: .035"
- 2010 Camaro with 3.6 V6: .043"

- 1969 Charger with 225 I6: .035"
- 2010 Charger with 2.7 V6: .050"

Notice the trend: from smaller gaps to larger gaps, fuel delivery method irrespective (larger gaps actually are on multiport injected engines).

Bill Robertson
#5939

[DCUK Martin]

Bullshit.

Which part?

You're now going against what you yourself said:



Do not compare a 1981 DeLorean to a 2011 model anything -- compare it to its contemporaries:

... and then you linked to a reference showing that its european contemporaries were much the same - you've conveniently ignored that salient point. :dork:

Seeing as you're so fond of repeating yourself, I'll join in:

The DeLorean engine as designed is very reliable and does not suffer disproportionately from ignition system issues. Changing the ignition system (on an original engine) is not going to give you any advantages over a properly working original system.

Quoting spark gaps in other cars is like judging their performance on the size of the wheels, it's meaningless. :thankyou:

[content22207]

Quoting spark gaps in other cars is like judging their performance on the size of the wheels, it's meaningless. :thankyou:

Society of Automotive Engineers Paper 720007, p. 60: "The conclusions reached as a result of this investigation are summarized below. Even though these conclusions are based on test results obtained with one basic engine, the trends observed should be similar to what would be expected of all modern engines."


Notice the trend: from smaller gaps to larger gaps, fuel delivery method irrespective (larger gaps actually are on multiport injected engines).

From the early 1970's onward, up to the present day, the trend has been larger plug gaps. .026" was very rare in 1981.

Bill Robertson
#5939

[content22207]

Show me spec on current production cars and their plug gaps from today? 0.7mm is still pretty vanilla flavoured AFAIK.

The largest selling car in Great Britain in 2010 was the Ford Fiesta. Spark plug gap: 1.3 mm (.051").

Bill Robertson
#5939

[content22207]

Spark plug gap on the Eagle Premier PRV: .030-.035".

Bill Robertson
#5939

[Ron]

50 pages, and "performance" still includes horsepower and emissions...

[content22207]

19 pages actually (48-66).

First page (48 ): authors define "performance" as cyclic combustion variations and emissions.

You have to actually READ the study....

Bill Robertson
#5939

[Ron]

I was talking about this thread...

[content22207]

This thread only has 6 pages.

Bill Robertson
#5939

[Ron]

The webpages in this thread average 10 pages each. 10 webpages x 5 pages = 50 pages.

I shall try to be more precise in the future.:blackeye:

=====


This thread only has 6 pages.

Bill Robertson
#5939
There were actually 5.2 at the time you posted the above.

=====

"Performance" still includes horsepower and emissions.

[content22207]

Let's stick to the controversy at hand: does increasing secondary voltage and widening the plug gap improve "performance," by whatever measure you want to use, or not?

On my side:
- An SAE research paper by AC Delco engineers, vetted by Lucas, Ford, and Champion
- Historical auto manufacturer practices from the 1970's to the present day

Bill Robertson
#5939

[stevedmc]

I believe this argument and most other Bill/Martin arguments can be summed up in just two sentences:

1. Deloreans suck and Bill does his best to make his not so sucky.

2. Deloreans suck and Martin likes it.

[Ron]

First, I said pages ago that you may have stumbled on a combination that performs better and I too would like to see it...untill then, I'll bite this once and share the following thoughts.

I will say increasing secondary voltage OR widening the plug gap will increase energy at the plug gap. (Still wondering what that resistor in the rotor you keep bitching about is for ;-)

"Performance" includes horsepower and emission (NOT semantics here). I have no doubt that what you are doing could make a D run faster (or, conversely, cleaner for that matter). The engineers had trade offs between the two to contend with. Considering the type of car it is (was), you can bet your bottom dollar that they pushed the emissions as far as they could get away with. I don't doubt that they (basically) knew what is in the pages you posted [Who would have published it back then?] and know they had access to larger coils and gaps...and tried them. Increasing the energy changes the curve...will the burn then occur at the optimum rate, max at the correct piston-crankshaft location, change temps, etc., etc.? Who knows?...I must strongly suspect that you are causing polluting well beyond a point of passing an emission inspection, or, the change in power is insignificant.

[Ron]

I believe this argument and most other Bill/Martin arguments can be summed up in just two sentences:

1. Deloreans suck and Bill does his best to make his not so sucky.

2. Deloreans suck and Martin likes it.

1. My Delorean does not suck.

2. You suck.

3. The moderators suck (especially Mike).

[content22207]

I will say increasing secondary voltage OR widening the plug gap will increase energy at the plug gap.

You want to answer this one, Steve?

Bill Robertson
#5939

[stevedmc]

I will say increasing secondary voltage OR widening the plug gap will increase energy at the plug gap.

Wrong. Widening the plug gap without increasing voltage will turn your ignition to sh!t. Sorry for the language but Deloreans are teaching me to cuss.

Edit to clarify my response: How the hell do you think spark is going to jump across a wider spark plug gap if you don't increase voltage?

[stevedmc]

1. My Delorean does not suck.

2. You suck.

3. The moderators suck (especially Mike).


For the record, Ron's original response was:

1. My bone stock Delorean does not suck.

2. You suck.

3. The moderators suck (especially Mike).

Does anyone notice what he changed?

[Ron]

Widening the plug gap without increasing voltage will turn your ignition to sh!t. Sorry for the language but Deloreans are teaching me to cuss.I agree. The engineers have figured out the optimum gap for the given setup. Screw with it (and nothing else) and you are probably screwing up! (see below)


Edit to clarify my response: How the hell do you think spark is going to jump across a wider spark plug gap if you don't increase voltage?
The same way it jumps across when some dumbass doesn't change his plugs out and there is hardly enough material left to recognize that it was an electrode.

My stock coil will jump a half inch or so...surely you arent talking about boring a relief hole in your piston to hanldle a greater gap. Next you will be carbing your car.
=====
Bill,
Try to carry on a reasonable conversation and you throw a lightweight at me that don't even know E=I*R

I'm done.

IKYCYC

[Soundkillr]

I agree. The engineers have figured out the optimum gap for the given setup. Screw with it (and nothing else) and you are probably screwing up! (see below)

The same way it jumps across when some dumbass don't change his plugs out and there is hardly enough material left to recognize that it was an electrode.

My stock coil will jump a half inch or so...surely you arent talking about boring a relief hole in your piston to hanldle a greater gap. Next you will be carbing your car.
=====
Bill,
Try to carry on a reasonable conversation and you throw a lightweight at me that don't even know E=I*R



I'm done.

IKYCYC

Lol, I like you Ron and wish to subscribe to your newsletter....:)

[stevedmc]

I agree. The engineers have figured out the optimum gap for the given setup. Screw with it (and nothing else) and you are probably screwing up! (see below)

The same way it jumps across when some dumbass don't change his plugs out and there is hardly enough material left to recognize that it was an electrode.

My stock coil will jump a half inch or so...surely you arent talking about boring a relief hole in your piston to hanldle a greater gap. Next you will be carbing your car.
=====
Bill,
Try to carry on a reasonable conversation and you throw a lightweight at me that don't even know E=I*R

I'm done.

IKYCYC


Your first sentence said you agree with me that widening gap without increasing voltage is bad. Then you go on to say you can gap yours as far as half an inch without increasing voltage. Wow.

[Ron]

Lol, I like you Ron and wish to subscribe to your newsletter....:)Funny you should say that...I just landed a new advertiser for "Hacking Your D" and was eying this:

4707[

[content22207]

Edit to clarify my response: How the hell do you think spark is going to jump across a wider spark plug gap if you don't increase voltage?

It won't.

Voltage must increase until it reaches a level sufficient to ionize the air between the electrodes. If that level is never reached, electrical current in one electrode will never flow to the other one. That is why spark plugs need a transformer (coil) in the first place, otherwise you could simply run your car with the distributor connected directly to the alternator.

Bill Robertson
#5939

[Ron]

Your first sentence said you agree with me that widening gap without increasing voltage is bad. Then you go on to say you can gap yours as far as half an inch without increasing voltage. Wow.NO. You responded to a post where I flatly stated that widening the gap WILL increase the energy at the gap (that E=I*R thingy I spoke of) -- Then I agreed with you that widening the gap will turn the ignition to shit.

[content22207]

I agree. The engineers have figured out the optimum gap for the given setup.

Incorrect -- Bosch figured out the maximum voltage their Blue coil could handle, then dumbed down ignition accordingly. That is why Bosch ignition looked so outdated against other manufacturers such as Delco and Motorcraft even in the 1970's.

Bosch ignition is not optimized -- it is minimized.

No one outside of a narrow segment of the narrow European market ever used it. Bosch ignition was adequate in Europe because:
- Their compression ratios were higher
- Their fuel mixtures were richer
In the North American market, it is barely functional at best, with absolutely no wiggle room for variation or degredation. That is one reason why a DeLorean engine can run acceptably one day, then suddenly run very badly the next.

Bill Robertson
#5939

[Ron]

It won't.

Voltage must increase until it reaches a level sufficient to ionize the air between the electrodes. If that level is never reached, electrical current in one electrode will never flow to the other one. That is why spark plugs need a transformer (coil) in the first place, otherwise you could simply run your car with the distributor connected directly to the alternator.

Bill Robertson
#5939
Thank you for proving to everyone that has ever changed a set of nearly worn out spark plugs or found a running engine with a set of wide gaped plugs in an otherwise stock vehicle that you are full of shit.

[stevedmc]

NO. You responded to a post where I flatly stated that widening the gap WILL increase the energy at the gap (that E=I*R thingy I spoke of) -- Then I agreed with you that widening the gap will turn the ignition to shit.

How the hell is widening a gap, without increasing voltage, increase energy? All you are going to do is cause ignition problems and you will end up not reliably burning fuel. Yes it might work, you might even be able to run a screwed up spark plug, but you are not going to ignite all of your fuel. It will not be reliable. You will just be wasting fuel.

[stevedmc]

Then I agreed with you that widening the gap will turn the ignition to shit.

You took my statement way out of context. I said that widening the gap WITHOUT INCREASING VOLTAGE will turn the ignition to shit.

[content22207]

Thank you for proving to everyone that has ever changed a set of nearly worn out spark plugs or found a running engine with a set of wide gaped plugs in an otherwise stock vehicle that you are full of shit.

Worn out spark plugs cause an engine to misfire and run badly. That is why you change them.

Bill Robertson
#5939

[stevedmc]

Thank you for proving to everyone that has ever changed a set of nearly worn out spark plugs or found a running engine with a set of wide gaped plugs in an otherwise stock vehicle that you are full of shit.

I guess we should all drive our deloreans on 30 year old spark plugs then and never inspect them.

[Ron]

How the hell is widening a gap, without increasing voltage, increase energy?
All you are going to do is cause ignition problems and you will end up not reliably burning fuel. Yes it might work, you might even be able to run a screwed up spark plug, but you are not going to ignite all of your fuel. It will not be reliable. You will just be wasting fuel.

How many times and how large do I have to write the word?
Increasing the gap WILL increase the voltage at the plug. It's a fact despite what Bill says. It's physics. The voltage at the plug will increase as you widen the gap until it's so wide that the coil can not produce enough to make it jump the gap. Haven't you ever pulled a coil wire an watched how far it will jump? Sure you have! Have you ever seen a (real) spark plug that you could gap anywhere near that wide? No.

[stevedmc]

You don't know what you are talking about. I installed a performance coil and increased my plug gap without increasing voltage (back when I had silly ideas like you).

Guess what happened? The damn thing started misfiring and many times it wouldn't even start. There was a really bad fuel smell back there.

I returned my plug gap back to stock specs and everything was fine.


When I got around to redoing my wiring I increased my voltage going into my performance coil, increased gap, and things were fine.

I am speaking from experience. You aren't.

[content22207]

Haven't you ever pulled a coil wire an watched how far it will jump? Sure you have! Have you ever seen a (real) spark plug that you could gap anywhere near that wide? No. [/SIZE]

Atmospheric conditions inside a combustion chamber (pressure, temperature, turbulence, mixture homogeneity, etc) are totally different than the outside world -- duh.

It's kind of like lighting a candle in the wind.

Bill Robertson
#5939

[Ron]

Worn out spark plugs cause an engine to misfire and run badly. That is why you change them.

Bill Robertson
#5939
They misfire and run bad because what's worn about them is the electrode is burn away creating a larger gap which increases the voltage which changes the curve which makes the max burn happen at the wrong time (to say the least) which causes it to run badly (which fowls the plug which causes a misfire).


I guess we should all drive our deloreans on 30 year old spark plugs then and never inspect them.No. From that, you should be guessing that since stock engines run with worn plugs and wide gaps, spark must be jumping across the worn/wider gaps.
So I ask you, "How the hell do you think spark is going to jump across a wider spark plug gap if you don't increase voltage?"

[content22207]

So I ask you, "How the hell do you think spark is going to jump across a wider spark plug gap if you don't increase voltage?"

It won't. Put a timing light on the plug -- it won't be firing.

Bill Robertson
#5939

[Ron]

Worn out spark plugs cause an engine to misfire and run badly. That is why you change them.

Bill Robertson
#5939
As the engine runs the plug wears and the gap gets wider -- but it keep running quite some time, now don't it?


Thank you for proving to everyone that has ever changed a set of nearly worn out spark plugs or found a running engine with a set of wide gaped plugs in an otherwise stock vehicle that you are full of shit.
AGAIN.

P.S. Do you two have an identity crisis going on?

[stevedmc]

So I ask you, "How the hell do you think spark is going to jump across a wider spark plug gap if you don't increase voltage?"

I never said it would. This is the question I keep asking you.

No one else on this thread is saying the crap you are saying. There is no debate saying you can or can't increase gap with it without the increased voltage.

The debate is whether or not the increased voltage and gap actually increase performance. I don't know what you are smoking but I really need some of it.

If you want to argue just say we are full of shit for believing we have increased performance because of our higher gapped plugs. At least then you would have someone on your side.

[content22207]

No one else on this thread is saying the crap you are saying. There is no debate saying you can or can't increase gap with it without the increased voltage.

I don't think Ron or Martin has bothered to read the SAE paper posted earlier. For example, the engineer from Champion Spark Plugs on p. 62 said the same thing you are saying, and engineers from AC Delco concurred on p. 65.

From a historical perspective, wider plug gaps would never have been possible without:
- Breakerless ignition, which removed the inherent voltage limitations of breaker points
- New coil designs (General Motors adopted a coil mounted directly to the distributor cap)

Note that American manufacturers increased plug gaps on the same engines. For example, Ford's 250 inline 6 went from a .025" plug gap in 1969 to a .044" plug gap in 1980 on the same engine. What changed between 1969 and 1980? I'll give you a hint: it wasn't the engine.

Bill Robertson
#5939

[Ron]

For the record, Ron's original response was:

1. My bone stock Delorean does not suck.

2. You suck.

3. The moderators suck (especially Mike).

Does anyone notice what he changed?

Yeah, I have a DMCH headlight switch, so it's not bone stock. :nervous:

[nullset]

Here's what Ron is trying to explain…..

The spark plug will fire at whatever voltage is sufficient to bridge the gap.

If you have a coil that can produce up to 1.21 jigga-volts, but the air/mixture/etc breaks down at 25 volts, guess how much voltage is going across that gap? 25V.

Now, let's say you double that gap. If we wave our hands and summon magic (seriously, I don't feel like looking up the equations right now), we'll see that the voltage at which the spark occurs (breakdown of atmosphere) increases, because of the larger gap.

Simply increasing the gap WILL increase the voltage at the plug. If that voltage exceeds what your coil is capable of creating, no spark will happen.

The key to all this is just WHEN that breakdown occurs. Just putting in a higher voltage coil and a wider gap will not necessarily improve things without other changes.

The timing would probably need to be altered at best. Those modern engines running larger plug gaps also likely have much more intelligent electronics to fire things at just the right time.

Of course, ignore that last paragraph if you want. I'm not 100% sure that they are all doing that, but if your goal is maximum efficiency and performance, that'd be the best way. They also have lots of other new features…..

--buddy

[content22207]

The timing would probably need to be altered at best. Those modern engines running larger plug gaps also likely have much more intelligent electronics to fire things at just the right time.

No "intelligent electronics" in the 1970's (no moreso than the Bosch ECU).

American manufacturers did advance ignition timing for emissions purposes in the 1970's, which led to increased chances of misfiring. That's where the larger diameter distributor caps came from -- to increase spark duration. Negative effects of advanced ignition timing are discussed in several places of the afore mentioned SAE paper (for example, p. 59 and p. 61).

DeLorean base timing was advanced from 10 degrees (Volvo North American spec on the exact same engine) to 13 degrees for the same reason -- to reduce emissions. Unfortunately spark duration was unchanged (Volvo PRV ignition is 100% identical to DeLorean ignition -- even the ECU's are identical). DeLorean owners may want to note Delco engineers' findings on p. 55: "Figure 22 demonstrates that the disadvantages of a short spark duration ignition system can be offset by increasing the spark plug gap..." There is little we can do to change spark duration, but the negative effects of advancing base ignition time 3 degrees can be offset by increasing plug gap.

BTW: My engine is timed 10 degrees BTDC, which is one reason my car is faster than the rest of yours. Note that my distributor is curved for that base ignition time -- it has a much more steeper advance curve than a stock DeLorean unit. Do not retard your ignition back to 10 degrees BTDC and expect the same results without also swapping out the distributor.

Historical curiosity: it appears that DeLoreans were originally supposed to be timed 10 degrees BTDC just like their North American Volvo cousins -- note Figure 28 on Page C:05:03 of the Workshop Manual. DMC did not piggyback on Volvo's PRV certification -- D19, D20, and D21 were used for DeLoreans' own certification. Apparently in the process ignition timing was advanced and the distributor was dumbed down. DeLoreans lack two major emissions devices present on Volvo B28F -- EGR and air injection.

Bill Robertson
#5939

[nullset]

No "intelligent electronics" in the 1970's (no moreso than the Bosch ECU).
#5939

I like how you take the one part of my post that I explicitly stated I didn't know whether it was accurate or not, and write a novel on why you disagree.

You also didn't address the first part - the part where I explain why increasing the plug gap DOES increase voltage, as Ron indicated.

Debate technique: If you are found to be wrong on one point, quickly throw something else out there to distract the person you're debating with and keep moving constantly.

--buddy

[content22207]

I agree with your explanation of ionization.

The low compression, lean burn combustion chamber conditions that started in the 1970's, and which were very much present when DeLoreans were introduced in 1981, are counter productive to combustion. To offset these inhibiting characteristics, American and Japanese manufacturers adopted higher voltage ignition and widened the spark plug gap, which led to higher current ionization and better combustion. Some manufacturers also increased spark duration by enlarging the distributor cap and rotor.

Bosch stands virtually alone in keeping its spark plug gaps unchanged after the switch from breaker points to breakerless ignition.

I disagree completely with your assertion that HEI depends upon "advanced electronics" (your words. not mine) beyond basic breakerless ignition technology, and I disagree with your assertion that timing must be altered for HEI, both of which are as wrong as can be. Historical evidence such as Ford's Duraspark module compared the Bosch ECU disproves the former, and Volvo base timing compared DeLorean timing disproves the latter.

Bill Robertson
#5939

[Ron]

You took my statement way out of context. I said that widening the gap WITHOUT INCREASING VOLTAGE will turn the ignition to shit.

Sorry, I missed this one:
No, I never thought that and have said quite clearly that widening the gap alone will increase the voltage all along because it is impossible to do, so I assumed you knew I didn't believe that part (My mistake). An honest mistake, but again, my mistake.


Then you go on to say you can gap yours as far as half an inch without increasing voltage. Wow.

My stock coil will jump a half inch or so...surely you arent talking about boring a relief hole in your piston to hanldle a greater gap. Next you will be carbing your car. I just don't see the "without increasing the voltage" part.
You flatly put words in my mouth...which contradicts something I said was impossible. Wow.

It seems to me you would get all of this from here (http://dmctalk.org/showthread.php?1334-High-Energy-Ignition-(HEI)&p=16919&viewfull=1#post16919).

=======

No one else on this thread is saying the crap you are saying. There is no debate saying you can or can't increase gap with it without the increased voltage.
What do you call this?


I will say increasing secondary voltage OR widening the plug gap will increase energy at the plug gap.
You quoted the above and posted.

Wrong. Widening the plug gap without increasing voltage will turn your ignition to sh!t. Sorry for the language but Deloreans are teaching me to cuss.

Edit to clarify my response: How the hell do you think spark is going to jump across a wider spark plug gap if you don't increase voltage?

Looked like YOU were to me!
=====



The debate is whether or not the increased voltage and gap actually increase performance. I don't know what you are smoking but I really need some of it.
No. The debate was whether changing a coil alone would increase performance.

I agree with the others -- Not by changing out a good stock coil alone. The stock coil can supply all the energy the stock plugs need to fire correctly. The perfect coil will only produce enough energy to fire the plug, no matter how many gazillawatts it has "in reserve".
and then on to include the definition of "performance" in this thread...
I guess it is safe to assume you didn't mean it was "Wrong (http://dmctalk.org/showthread.php?1334-High-Energy-Ignition-(HEI)&p=16904&viewfull=1#post16904)" that increasing secondary voltage increased energy at the gap, so, since you claimed it isn't from widening the gap and that it will not fire w/o increasing the voltage, I have to throw the question back at you. I already answered it anyway, again, widening the gap raises the voltage.

[Ron]

You don't know what you are talking about. I installed a performance coil and increased my plug gap without increasing voltage (back when I had silly ideas like you).

Guess what happened? The damn thing started misfiring and many times it wouldn't even start. There was a really bad fuel smell back there.

I returned my plug gap back to stock specs and everything was fine.


When I got around to redoing my wiring I increased my voltage going into my performance coil, increased gap, and things were fine.

I am speaking from experience. You aren't.You don't know what you are talking about. You are not on the same page...- Show me where I said anything about changing input voltage...you began all this by saying it was wrong for me to say changing the plug gap would increase energy at the gap (OR by using a larger coil...surely you didn't mean it.)
Are you skimming posts?
I'm sorry you were silly enough not to follow directions or change out several things at once back then. The rest sounds like you should of redone your wiring to begin with to me.

I have to admit, after decades as a mechanic, I don't have a lot of experience second guessing the engineers on this type of thing. So I'll shut the hell up.

[content22207]

... widening the gap raises the voltage.

The problem is the Bosch Blue coil does not produce an infinite supply of voltage. Quite the contrary -- it produces a very finite amount of voltage (about 18,000 volts max, IIRC). There *WILL* come a point where the plug gap can not be widened any further and the coil will be able to supply the voltage necessary to jump it. I suspect .026" is very close to that limit.

Coil output is of course a multiple of input. Increasing primary voltage into the coil will increase secondary output voltage. Unfortunately the Bosch Blue coil does not seem to be able to handle more than 6-8 volts input, which does make sense when you consider that it was designed in the late 1960's when that was a typical coil supply voltage (due to breaker point limitations already discussed).

Rumor is that running more than 8 volts into a Bosch Blue coil for an extended period of time will damage it.

Higher winding coils (so called "performance" coils) produce more secondary voltage for the same amount of input voltage, simply because they have a higher ratio of secondary to primary windings. If you replace a Bosch Blue coil with a higher winding coil, you will be able to jump a larger plug gap, even with no other changes to the ignition system.

What Steve discovered was that his high winding coil also had a finite amount of voltage it could produce. He exceeded the gap that his coil could reliably jump, and started misfiring accordingly.

This is the crucial difference: his high winding coil was not limited to 6-8 volts input. By increasing the amount of voltage going into his coil, he could increase the amount of secondary voltage produced by the coil. The widened plug gaps that before could not be jumped reliably now were jumped regularly.

That is why we caution owners not to widen their plug gaps without also increasing primary voltage supply, even if they are running a higher winding coil.

I can't speak for MSD coils, but a Pertronix coil, with 12.5 volts primary voltage, definitely has no problem producing enough secondary voltage to reliably jump a .05" plug gap -- I do so every time I drive my car all the way to New York/New Jersey, or New Orleans, or Kentucky, or Florida next summer (these distances are cited merely to indicate the extended periods of time a Pertronix coil can operate off 12.5 volts).

Bill Robertson
#5939

[Ron]

And just what in that post do you think I didn't know (other than Steves experiences), what does any of it has to do with increasing the performance by changing the coil alone on a stock car and whether it is fair for you to not include emissions as a part of "performance"?

And last but not least, if increasing the plug gap doesn't increase voltage at the plug and a widened plug gap will not fire w/o an increase in voltage, how the hell do you explain worn plugs and wide gaps in a running engine.
[You can't have it both ways even if there are two of you. Do you really think I don't know that you too know (knew) what was going on..LMFAO]

[Ron]

There *WILL* come a point where the plug gap can not be widened any further and the coil will be able to supply the voltage necessary to jump it.
Bullshit.
I have it from more than one reliable source that widening it at all will not allow the spark to jump, because there will be no increase in voltage, which is required to make the longer jump.
:screwy:

[Ron]

Atmospheric conditions inside a combustion chamber (pressure, temperature, turbulence, mixture homogeneity, etc) are totally different than the outside world -- duh.

It's kind of like lighting a candle in the wind.

Bill Robertson
#5939
You are right...no fuel to help the spark travel along on because it's a lot leaner out here...maybe I should write a paper on...um...oh yeah, someone already did that.

[Ron]

I don't think Ron or Martin has bothered to read the SAE paper posted earlier. For example, the engineer from Champion Spark Plugs on p. 62 said the same thing you are saying, and engineers from AC Delco concurred on p. 65.

Really? I see both as confirming what Martin has been saying all along. Doesn't address what I've been saying except for one thing much, increasing the gap alone causing an increase in voltage at the plug (thanks for an accepted references).
"Larger gap spacing results in greater voltage requirements and increased energy in the initial release of the capacitive portion of the discharge." [pg. 62, Emphasis added]

Like I said before, this is nothing new, especially to engineers in 1981:
"SINCE READING in 1960 the first papers dealing solely with cycle-to-cycle combustion variations, I have kept a keen interest in the subject. The "conclusions arrived at them are still valid, although some clarifications of the mechanisms have been shown..." [Pg 63, Emphasis added]

BTW- The paper also says performance includes power and emissions...


What changed between 1969 and 1980? I'll give you a hint: it wasn't the engine.

Bill Robertson
#5939
Yep. Same exact engine for 10 years :screwy:
Which has little to nothing (as usual) to do with the questions at hand.

Was it diesels started to out perform gas burners, with no spark gap or coil at all?

======

Well watch is about over. Please continue on with extraneous truths.

CYA! :popcorn:

[content22207]

Was it diesels started to out perform gas burners, with no spark gap or coil at all?

Yes indeed, with compression ratios almost three times as high.

Which releases more energy: a spring compressed to 1/8 its original length, or a spring compressed to 1/20 its original length?

To be brutally honest Ron, if you don;t understand the difference between gasoline combustion and diesel combustion, you have no business commenting in this thread in the first place.

Bill Robertson
#5939

[content22207]

Back to the thread at hand:

If an owner wants:
- decreased emissions
- more reliable combustion
- more complete combustion
especially in a lean burning engine like the a DeLorean PRV, there is no better way to accomplish that than to increase secondary ignition voltage and spark plug gap.

Engineers from AC Delco, Lucas, Ford, and Champion all agree.

Every American and Japanese car manufacturer came to the same conclusion, and did just that in the 1970's -- a practice that continues to this day (they did so first on the exact same engines that had been running smaller plug gaps with breaker points -- ignition technology that inherently limited secondary voltage and spark plug gaps, then continued doing so on newer designed engines).

A subset of European manufacturers continued using lower voltage ignition and smaller plug gaps, even after breakerless ignition made higher voltage ignition and larger plug gaps possible. Evidence points to a reluctance to redesign the ignition coil -- a necessary step towards high energy ignition.

The PRV, as used in a DeLorean, can benefit greatly from higher voltage ignition. That is why Renault/Chrysler started using higher voltage capacitive coils and a larger plug gap for the 3.0 version of our engines (Autozone shows the 3.0 PRV plug gap as .044", but other online sources show it .030-.035" -- both are wider than the original DeLorean spec).

Bill Robertson
#5939

[Bitsyncmaster]

In the late 60s the big new thing was capacitive discharge ignition. The problem with gas engines back then was leaded gasoline fouling the plugs. So they decided to burn the plugs hotter and open the gap with capacitive discharge ignition. I don't hear much about that anymore. Unleaded gas was started in the early 70s.

Race engines always needed higher power coils, dual points etc. to run 10000 RPM. That was due to the dwell times are just to short to get the energy into the coils.

I'm still open for info on what advantage there is to using a different spark set up on our low compression engines. What is better, more voltage or more current. Does a higher voltage spark ignite fuel faster than a lower voltage with more current? If it ignites the fuel faster, wouldn't you need more advance timing? So as long as you don't get any miss fires what are the benefits?

Does the higher voltage cause our distributor cap to fail sooner since it was not designed for that voltage.

[content22207]

In the late 60s the big new thing was capacitive discharge ignition. The problem with gas engines back then was leaded gasoline fouling the plugs. So they decided to burn the plugs hotter and open the gap with capacitive discharge ignition. I don't hear much about that anymore. Unleaded gas was started in the early 70s.

The higher voltages possible with capacitive coils simply were incompatible with breaker points.

Everything eventually went capacitive after after breakerless ignition. GM was the first in the 1970's, mounting a capacitive coil directly to the distributor cap. Ford went capacitive when they introduced TFI modules in the 1980's (the module mounted to the distributor body). All distributor packs were capacitive. I don't think there has been a new car model with inductive ignition since the mid 1980's.

Bill Robertson
#5939

[stevedmc]

I'm not going to post something saying I've been a mechanic for 30 years, blah blah blah. I'm just going to say facts which I have been doing all along.


About 6 months ago I decided to upgrade my ignition. I purchased a high performance coil, MSD spark plug wires, and new spark plugs.

I gapped my new plugs to .05 and didn't bother to increase voltage going into the ignition coil. I left the resistor grid wired to put 6 - 8 volts into the coil.

The problems were very quick to surface. The car wouldn't alway start and when it did it ran like crap. Many of my friends were quick to blame my fuel system saying the engine was flooded. Also my gas mileage dropped drastically.

I then pulled each plug and regapped them to .026. The car ran perfect after that.

When I got around to redoing the wiring in my engine bay I decided to rewire the resistor grid to provide 12 volts into the ignition coil. Then I gapped my plugs to .05

The car ran perfect at .05 only after I increaed voltage going into the coil.

Ron can post all the foolishness he wants but I am not responding to anymore of his posts on this subject.

[content22207]

I just corresponded with an owner who may have wired his coil backwards: "The input to the coil is about 4.75V and the output is over 7.5V." If that statement is correct, not just written backwards, he definitely has the wires on the wrong terminals.

Why is this such a common problem in the DeLorean community? Bosch coils may be labeled bass ackwards, but Pertronix and MSD coils clearly have their positive and negative terminals labeled with "+" and "-" signs.

Bill Robertson
#5939

[Ron]

what changed between 1969 and 1980? I'll give you a hint: it wasn't the engine.was it diesels started to out perform gas burners, with no spark gap or coil at all?
yes indeed,...
To be brutally honest Ron, if you don;t understand the difference between gasoline combustion and diesel combustion, you have no business commenting in this thread in the first place.

:rofl:

[content22207]

Ron can post all the foolishness he wants but I am not responding to anymore of his posts on this subject.

I'm pretty sure Ron and Martin realize they are wrong, and rather than taking their lumps they are just trying to steer this thread off in tangential directions.

In 1981 Bosch ignition stood alone with low voltage coils and small spark plug gaps. That is an uncontestable historical fact.

By 1981 every other ignition manufacturer had already adopted higher voltage coils and larger plug gaps, even for engines that previously used low voltage coils and small plug gaps (the change can not be attributed to new engine designs, although some engines that previously were high compression did have their compression ratios dropped).

I have no idea why Bosch didn't upgrade to HEI.

The number of vehicles running Bosch ignition in the 1980's was an extremely small segment of the global car market. Unfortunately DeLoreans were in that small group.

I find it particularly interesting that Chrysler used higher voltage ignition and wider plug gaps for its 3.0 iteration of the PRV, while Volvo continued to use a Bosch ignition system and .028" plug gaps on the B280 (I have no idea who made Chrysler's 3.0 ignition). Starting in 1988, for the same basic engine, the North American user equipped it with HEI while the European user stuck with earlier spec ignition -- a clear dichotomy if I ever saw one.

Bill Robertson
#5939

[Ron]

I'm not going to post something saying I've been a mechanic for 30 years, blah blah blah. I'm just going to say facts which I have been doing all along.You brought it up and said I didn't have any (experience). I don't see why I shouldn't tell you mine.


About 6 months ago I decided to upgrade my ignition. I purchased a high performance coil, MSD spark plug wires, and new spark plugs.

I gapped my new plugs to .05 and didn't bother to increase voltage going into the ignition coil. I left the resistor grid wired to put 6 - 8 volts into the coil.
I already said I'm sorry you were silly enough not to follow the directions.:dunno:



The car ran perfect at .05 only after I increaed voltage going into the coil.
I told you you were not on the same page...That is primary voltage! I have been talking about secondary voltage (relatively more coils in the secondary = more voltage output) and about voltage at the plug gap. You are putting words in my mouth (or thoughts in my head?), again. I've seen that idea here, but I didn't say it.

Ron can post all the foolishness he wants but I am not responding to anymore of his posts on this subject.Good. You really haven't been doing that anyway...most of it was pick and poke instead...and the majority of the rest on some other page.

======
I was asked to do this, so here goes for the benefit of the doubt:

Take a deep breath, calm down, get on the same page and read this:
From the beginning, primary voltage...
Voltage (E) = Amperage(I) x Resistance(R), so R = E/I. At the moment before a spark, the resistance at the plug gap is a fixed value (it changes afterward but too involved to get into here), so, if we increase the primary's input voltage, the secondary's output voltage must increase. Now, (P)ower = I x E. Since we increased E and I (it will draw what it wants), we increase P. This is all you had to do to increase energy at the gap. You could of accomplish this by bypassing 1/2 or all of the resistor grid (that's what its job is!). Not a good idea...the rotor, especially one with a resistor in it, will not like it on a long trip (The more you run through them the more heat they give Sparky [oops FS, um,] off...); The change in energy changes the burn characteristics, including the moment of max burn (we want this to happen when the piston/crank is at the optimum position. [For those who wonder why timing is often set to a point before the position even reaches the top...That is basically why...the higher the RPM the sooner we have to start the burn...time]; The list goes on and on.
FWIW, I believe you (at least basically) knew most of this.
=====
Now, the other page...the 'a plug with widened gap will not fire' - '"performance" includes HP and emissions' page.

I was, collectively, being told it is wrong to say increasing gap alone increases energy at the gap. And, that if we widen a gap, there would not be enough voltage to jump it.
That leaves us (me anyway) wondering how engines with wide/worn gaps run. [Bill said it won't. You didn't answer, even though the question was directed to you.] I see it like, we increase R by widening the gap and it still runs, so it must be sparking. So, we must have increased the energy. Now, we are back to P = I x E. We raised P, so... :dunno:

As for "performance" includes HP and emissions, that was aimed at Bill, IIRC. Besides, he has repeatedly ignored the question from almost everyone since he knows most of ALL of the above (enough to be dangerous anyway) and that it contradicts his 'coil alone improves performance' statement(s) and his glorious paper (that is supposed to shed new light on 1981 technology (while it points to and agrees with a 1960s paper :screwy:, and this particular point w/o question :screwy:).The screwball is arguing with himself.
...and wants me to argue with both of them (or should I say all three of you? :devil:)

[Ron]

Yeah, I have a DMCH headlight switch, so it's not bone stock. :nervous:OMG! I forgot to mention my speedometer and boost gauge.:blackeye::angry_whip:

[Ron]

I'm pretty sure Ron and Martin realize they are wrong, and rather than taking their lumps they are just trying to steer this thread off in tangential directions.No, you did that, as far as I am concerned, when you said that changing the coil alone would increase performance...I was in a neutral corner until then.
That invoked the performance/HP-emission crap you kept ignoring from most everyone.
But I see below you are trying to sneak it in now -- Along with your conclusions on their conclusions.

I wonder how long it will take you to pick on a another typo, verbiage, insignificant piece, etc, and start of on another tangent or explode with more extraneous truths.

"Delorean...lean burning...2011"
More fun than a barrel of monkeys.

Love ya Bill.
I'm done...really...truly.


Back to the thread at hand:

If an owner wants:
- decreased emissions
- more reliable combustion
- more complete combustion
especially in a lean burning engine like the a DeLorean PRV, there is no better way to accomplish that than to increase secondary ignition voltage and spark plug gap.

Engineers from AC Delco, Lucas, Ford, and Champion all agree.

Every American and Japanese car manufacturer came to the same conclusion, and did just that in the 1970's -- a practice that continues to this day (they did so first on the exact same engines that had been running smaller plug gaps with breaker points -- ignition technology that inherently limited secondary voltage and spark plug gaps, then continued doing so on newer designed engines).

A subset of European manufacturers continued using lower voltage ignition and smaller plug gaps, even after breakerless ignition made higher voltage ignition and larger plug gaps possible. Evidence points to a reluctance to redesign the ignition coil -- a necessary step towards high energy ignition.

The PRV, as used in a DeLorean, can benefit greatly from higher voltage ignition. That is why Renault/Chrysler started using higher voltage capacitive coils and a larger plug gap for the 3.0 version of our engines (Autozone shows the 3.0 PRV plug gap as .044", but other online sources show it .030-.035" -- both are wider than the original DeLorean spec).

Bill Robertson
#5939

[content22207]

But I see below you are trying to sneak it in now -- Along with your conclusions on their conclusions.

Not to point out the obvious, but I *DID* mention emissions (and fuel economy) in the very first post of this thread, as a quote from an even earlier post of mine in other thread....

Bill Robertson
#5939

[Farrar]

(I have no idea who made Chrysler's 3.0 ignition)

Probably Renault/Bendix; it was their powerplant. The Eagle Premier was derived from the R25. The car was originally to be marketed in the USA by AMC as a Renault. Chrysler’s acquisition of AMC came just prior to the car’s introduction, thus the change of badging and labels was rushed but the car’s production was not.

The original model (1988) of the Premier had AMC build plates on the driver's door, and even in 1989 the Premier an emissions decal under the hood that stated, "American Motors Corporation" and then in tiny letters, "Built by Chrysler." All models still had radiator hoses with the AMC logo.

It seems that Chrysler is in the habit of not changing what they yank from other manufacturers -- the Chrysler Crossfire's engine compartment is 100% Mercedes-Benz, right down to the German/English labeling, metric measurements, and a Mercedes-Benz logo on the air filter cover!

OK, that's enough trivia for one day. Back to our regularly scheduled pointless arguments. :lol:

Farrar

[stevedmc]

OK, that's enough trivia for one day. Back to our regularly scheduled pointless arguments. :lol:

You don't know what you are talking about. Our arguments are not pointless.

[Farrar]

You don't know what you are talking about. Our arguments are not pointless.

That was a pun. Point-less ... points ... ignition!

Ah, well.

Farrar

[content22207]

it was their powerplant.

Actually Volvo was the lead partner on the B280 redesign. Volvo also started using the new engine one year earlier: 1987. And Volvo owned the Douvrin tooling (note the scene in the Pennebaker documentary where Chuck Benington is explaining to JZD that Volvo wants royalties on DeLorean engines even though they were sourced from Renault).

The Eagle Premier was just Chrysler's way of satisfying Renault purchase requirements in the AMC acquisition. Nobody at Chrysler liked the car.

The most important thing about the 3.0 versus the B280 for the purposes of this thread is that Chrysler went with totally different ignition for what is basically the same engine, which clearly demonstrates:
- HEI works just fine on a PRV
- a major manufacturer itself chose HEI over low energy Bosch ignition for its PRV's (HEI on a PRV is not just the province of a few DeLorean owners cobbling something together from the pages of Jegs and Summit)

Bill Robertson
#5939

[Farrar]

Actually Volvo was the lead partner on the B280 redesign.

So AMC bought it from Volvo, or from Renault?

Farrar

[content22207]

Renault was calling AMC's shots by then. They had already pretty badly screwed up the company. Other than the Alliance, AMC was reduced to building rebadged Renault products that didn't sell worth a damn. Le Car? Give me a break.

Renault was a partner in the Douvrin plant. Volvo engineers did the redesign work (that's what members of Volvo forums claim).

Bill Robertson
#5939

[Farrar]

Renault was a partner in the Douvrin plant.

But did AMC buy the drivetrain from Renault, or from Volvo? That's all I want to know.

Farrar

[content22207]

AMC was Renault. Renault bought a controlling interest in the company in 1982. That's why AMC had to sell AM General (foreign companies weren't allowed to build US military weapons, at least not back then).

Bill Robertson
#5939

[Farrar]

So ... it was Renault's drivetrain?

Farrar

[sean]

So ... it was Renault's drivetrain?

Farrar

OMG! This is like a bad Abbott and Costello bit.

[Farrar]

OMG! This is like a bad Abbott and Costello bit.

:lol:

But I am guessing I play the part of Lou Costello... :(

Farrar

[sean]

:lol:

But I am guessing I play the part of Lou Costello... :(

Farrar

:D
Who is Lou? You is Lou?

[content22207]

So ... it was Renault's drivetrain?

Absolutely, just like Alliance drivetrains.

When Renault bought a controlling interest in AMC, they basically told everyone to shut up and build what they had already designed in France (Dick Teague tweaked things a bit for the American market, but the cars were unmistakably French). The Premier is no different than the Alliance -- a French car tweaked for the American market.

Fortunately Renault did not throw away AMC's own engine tooling. When Chrysler bought AMC, they were in desperate need of a cast iron 6 cylinder engine (Lee Iacocca did throw away Chrysler's 225 tooling). The Chrysler 4.0 is AMC's 258, built with AMC's own tooling (a wonderful little engine that traces its heritage all the way back to 1964). Chrysler also continued to produce AMC's V8, alongside its own V8 platform. Under Chrysler auspices AMC designed engines continued to be produced, using AMC's original tooling, until 2006.

Bill Robertson
#5939

[Farrar]

Probably Renault/Bendix; it was their powerplant.


Actually Volvo was the lead partner on the B280 redesign.


But did AMC buy the drivetrain from Renault, or from Volvo? That's all I want to know.


AMC was Renault.


So ... it was Renault's drivetrain?


Absolutely, just like Alliance drivetrains.

Okeydoke...


Probably Renault/Bendix; it was their powerplant.

Farrar

[content22207]

Volvo and Renault were both partners in the Douvrin plant (along with Peugeot of course). It's not as though you had two different suppliers of PRV engines. All PRV's came from the same place. They were just spec'd differently according to each manufacturer's needs.

The Pennebaker documentary records Volvo's demand for royalty payments from DMC, for engines sourced through Renault, because the tooling inside the Douvrin plant belonged to Volvo. That does make it appear that the PRV partnership was not evenly divided between the three manufacturers.

Volvo newsgroups make it sound as though Volvo engineers were primarily responsible for modifying the original odd fire design into the even fire B280, used first by Volvo in 1987, then by Renault in 1988 as the 3.0.

Interesting footnote: the bilge pump engine in my car is Peugeot sourced (it has a Peugeot engine number). It was built in the same Douvrin factory as all other DeLorean engines, but spec'd by Peugeot for its own use (in my case, an off-road marine application).

Bill Robertson
#5939

[cineman]

Volvo and Renault were both partners in the Douvrin plant (along with Peugeot of course). It's not as though you had two different suppliers of PRV engines. All PRV's came from the same place. They were just spec'd differently according to each manufacturer's needs.

The Pennebaker documentary records Volvo's demand for royalty payments from DMC, for engines sourced through Renault, because the tooling inside the Douvrin plant belonged to Volvo. That does make it appear that the PRV partnership was not evenly divided between the three manufacturers.

Volvo newsgroups make it sound as though Volvo engineers were primarily responsible for modifying the original odd fire design into the even fire B280, used first by Volvo in 1987, then by Renault in 1988 as the 3.0.

Interesting footnote: the bilge pump engine in my car is Peugeot sourced (it has a Peugeot engine number). It was built in the same Douvrin factory as all other DeLorean engines, but spec'd by Peugeot for its own use (in my case, an off-road marine application).

Bill Robertson
#5939

The evenfiring PRV was first introduced by Renault, with the 2.5lt turbo in the R25 and Alpine GTA, in 1985. The 2.8 and 3.0 of every other manufacturer came later.

regarding Volvo and Delorean, the castings numbers of heads and cams are in fact the one used from Volvo, so maybe that's why Volvo requested a royalty. I have bought documents in france, i will scan, from a Renault archive where is specified the first 500 or so engine for Delorean was of a kind ( quite all Volvo p/n ) and after they changed... my assumption is that they needed the first engines to be exactly like the Volvo one that was already certified emission for the USA, and that the engine in all the prototype and first cars, and after they changed it a bit...for royalty? power? emission? who know...

[Farrar]

Volvo and Renault were both partners in the Douvrin plant (along with Peugeot of course)....

I give up. Even if I'm right, I'm wrong. :lol:

Farrar

[content22207]

Dunno who is right or wrong, but I do know now that Renault was hemorrhaging money throughout the 1980's (just learned that looking up info for another thread).

I always assumed that since Renault was able to buy a controlling interest in AMC and build a new factory in Canada, they were profitable. Apparently nothing could be further from the truth. Renault lost money every year between 1980 and 1986, racking up a staggering $5.75 billion in losses (more than $11 billion in 2010 dollars). New management was able to turn a profit in 1987 and 1988, in no small part by selling Renault's share of AMC to Chrysler, but by the end of the decade things had turned sour again (profits plunged 87% in 1989 alone).

Must be nice to be a government owned auto manufacturer. Thank God that could never happen in the United States. Oh wait, nevermind....

Bill Robertson
#5939

[DCUK Martin]

2. Deloreans suck and Martin likes it.

Grow up. If there's a genuine need to reengineer something I'm there with bells on, but I'm a firm believer in "if it ain't broke, don't fix it"... with the additional caveat of don't go crowing from the rooftops using as flowery language as possible on "how badly engineered and sub-standard these silly little cars are!". Stick to the facts, wherever possible stickin gto solid engineering principles along the way....




Bosch ignition is not optimized -- it is minimized.

No one outside of a narrow segment of the narrow European market ever used it. Bosch ignition was adequate in Europe because:
- Their compression ratios were higher
- Their fuel mixtures were richer
In the North American market, it is barely functional at best, with absolutely no wiggle room for variation or degredation. That is one reason why a DeLorean engine can run acceptably one day, then suddenly run very badly the next.



What a complete and utter howler of a post!

1) Have you ever actually TRIED opening up the plug gaps on a stock coil? Given I *know* it'll maintain a spark under twice the pressure generated in a stock DeLorean engine, I'll cheerfully put money on it working just fine. Remember: I use it on my turbo engines under 15psi of boost producing well over 200hp. "Barely functional at best"?!?!?! Get a life...

2) You've got your facts completely backwards - it takes MORE energy to generate a spark when under more pressure, not less. I've repeated this fact a hundred times but you're still ignoring it.... can't think why.:umm:

3) Running a carburetor gives you much less control over the mixture and no engine likes to run lean, yet all will run pretty much fine when rich (not talking catalysts here!). The more you start to worry about emissions, the closer to stochiometry the engines are required to run. Stochiometry is where the spark plug has the easiest time.


How many times and how large do I have to write the word?
Increasing the gap WILL[/SIZE] increase the voltage at the plug. It's a fact despite what Bill says. It's physics.


Here's what Ron is trying to explain…..

The spark plug will fire at whatever voltage is sufficient to bridge the gap.

If you have a coil that can produce up to 1.21 jigga-volts, but the air/mixture/etc breaks down at 25 volts, guess how much voltage is going across that gap? 25V.

Now, let's say you double that gap. If we wave our hands and summon magic (seriously, I don't feel like looking up the equations right now), we'll see that the voltage at which the spark occurs (breakdown of atmosphere) increases, because of the larger gap.

Simply increasing the gap WILL increase the voltage at the plug. If that voltage exceeds what your coil is capable of creating, no spark will happen.

The key to all this is just WHEN that breakdown occurs. Just putting in a higher voltage coil and a wider gap will not necessarily improve things without other changes.

The timing would probably need to be altered at best. Those modern engines running larger plug gaps also likely have much more intelligent electronics to fire things at just the right time.

...

Debate technique: If you are found to be wrong on one point, quickly throw something else out there to distract the person you're debating with and keep moving constantly.

--buddy

Where's the "What he said" smiley gone....?


Bullshit.
I have it from more than one reliable source that widening it at all will not allow the spark to jump, because there will be no increase in voltage, which is required to make the longer jump.
:screwy:

Umm.... not sure what you meant there, Ron.


Yes indeed, with compression ratios almost three times as high.

Which releases more energy: a spring compressed to 1/8 its original length, or a spring compressed to 1/20 its original length?

To be brutally honest Ron, if you don;t understand the difference between gasoline combustion and diesel combustion, you have no business commenting in this thread in the first place.



Oh my gaaaawd. Did you really just write that? :lol: Your analogy of a spring is fundamentally flawed: You have to put the energy in to compress it in the first place, right? And as no energy transfer is 100% efficient, ipso facto more energy is lost compressing the gases in a diesel than in a petrol engine.

The efficiency of any heat engine is fundamentally linked to its compression ratio, but not for the reason you state.


Back to the thread at hand:

If an owner wants:
- decreased emissions
- more reliable combustion
- more complete combustion
especially in a lean burning engine like the a DeLorean PRV, there is no better way to accomplish that than to increase secondary ignition voltage and spark plug gap.

Engineers from AC Delco, Lucas, Ford, and Champion all agree.


That reads like one of those spam emails that says "As seen on TV and even Oprah!"

They don't "agree" with you Bill. I'd love to get a good running stock DeLorean on a gas analyser and dyno and let you do your best with the ignition to see if we get any improvements at all.... but that ain't gonna happen, so we'll just keep fighting on here...


I don't think there has been a new car model with inductive ignition since the mid 1980's.



You WHAT?! Complete and utter nonsense.... ask yourself why even modern cars use "coil packs" !?! Capacitive ignition was used for a brief period to overcome problem associated with coil charge times. Even a quick glance at Wikipedia tells me that:

"Capacitor discharge ignition (CDI) or thyristor ignition is a type of automotive electronic ignition system which is widely used in outboard motors, motorcycles, lawn mowers, chainsaws, small engines, turbine-powered aircraft, and some cars."

Well done demonstrating another yawning chasm in your knowledge.




About 6 months ago I decided to upgrade my ignition. I purchased a high performance coil, MSD spark plug wires, and new spark plugs.

...then did a bunch of othe rstuff to make it run right but you never said how it ran before you decided to "upgrade"?


I'm pretty sure Ron and Martin realize they are wrong, and rather than taking their lumps they are just trying to steer this thread off in tangential directions.

http://1.bp.blogspot.com/-llexKFzKFCo/TZYuSqBpqfI/AAAAAAAAJDo/7TdFM78qcr8/s320/KettleCallingPotBlack%255B1%255D.jpg




regarding Volvo and Delorean, the castings numbers of heads and cams are in fact the one used from Volvo, so maybe that's why Volvo requested a royalty.

Funny then that the numbers cast into DeLorean parts like the intake manifold, sump and more are actually Renault part numbers.... even the camshaft numbers Bill has posted in his Volvo literature are traceable Renault numbers....!




Must be nice to be a government owned auto manufacturer. Thank God that could never happen in the United States. Oh wait, nevermind....



Yeah, check out Renault's performance today....

[stevedmc]

...then did a bunch of othe rstuff to make it run right but you never said how it ran before you decided to "upgrade"? YEAH, I believe my statement saying, "Deloreans suck" is enough to explain why I upgraded. 16510 still sucks but its not as bad as before and I have slightly better gas mileage as a result of making it less sucky.

[sean]

Grow up.....

Now that's how to mutli-quote! Thanks Martin!


YEAH, I believe my statement saying, "Deloreans suck" is enough to explain why I upgraded. 16510 still sucks but its not as bad as before and I have slightly better gas mileage as a result of making it less sucky.

HA! Carbs....Reducing the level of DeLorean suck since 2000.

[content22207]

2) You've got your facts completely backwards - it takes MORE energy to generate a spark when under more pressure, not less. I've repeated this fact a hundred times but you're still ignoring it.... can't think why.:umm:

Because real engineers, who build ignition systems for a living, disagree with you?

For example, Pages 61 and 62 of the afore mentioned SAE paper (Lucas' commentary):
"The effects of spark duration, air-fuel ratio (A/F), compression ratio and ignition advance were observed.... [11:1 compression ratio results] For these conditions a 2 millisecond spark was adequate until the A/F exceeded 16:1, whereas for a 7:1 compression ratio 2000 milliseconds were necessary for this A/F.... The effect is aggravated by low compression ratio."

Page 64 [Delco engineers' response]:
"... Similarly, with higher compression ratios, the mixture temperatures and pressures at the time of ignition are increased. These conditions reduce the spark duration required to prevent any engine misfires for the same A/F."

This particular exchange involved the study's spark duration tests, but the effects of higher compression also apply to spark energy, gap projection, and electrode size: any given fuel/air mixture is easier to ignite under higher compression than the exact same mixture is under lower compression.

Bill Robertson
#5939

[nullset]

This particular exchange involved the study's spark duration tests, but the effects of higher compression also apply to spark energy, gap projection, and electrode size: any given fuel/air mixture is easier to ignite under higher compression than the exact same mixture is under lower compression.

Bill Robertson
#5939

Easier to ignite has nothing to do with the voltage required to break down the air gap of the spark plug.

The plug will spark at whatever voltage is sufficient to bridge the gap, no matter what the 'maximum output' voltage of your coil is, no matter what your compression ratio is, and no matter what your A/F is.

[sean]

HA! Carbs....Reducing the level of DeLorean suck since 2000.

For prosperity sake, Steve stole it from me but Im ok with that ;-)

[content22207]

Easier to ignite has nothing to do with the voltage required to break down the air gap of the spark plug.

The plug will spark at whatever voltage is sufficient to bridge the gap, no matter what the 'maximum output' voltage of your coil is, no matter what your compression ratio is, and no matter what your A/F is.

Easier to ignite has everything to do with how wide you set the gap. If you set the gap too narrow on a low compression engine (harder to ignite), you risk misfiring not only because the spark voltage will be too low, but because the flame front will be too small.

It's no historical coincidence that American manufacturers widened their plug gaps at the same time they were dropping compression ratios.

Bill Robertson
#5939

[Ron]

Bullshit.
I have it from more than one reliable source that widening it at all will not allow the spark to jump, because there will be no increase in voltage, which is required to make the longer jump.
Umm.... not sure what you meant there, Ron.
[Man, you're really going to make me work here....]

I was being sarcastic (Bill & Steve)....well, sardonic:

Well, It went like this:




I will say increasing secondary voltage OR widening the plug gap will increase energy at the plug gap.Wrong.Widening the plug gap without increasing voltage will turn your ignition to sh!t.
...
Edit to clarify my response: How the hell do you think spark is going to jump across a wider spark plug gap if you don't increase voltage

The same way it jumps across when some dumbass don't change his plugs out and there is hardly enough material left to recognize that it was an electrode.

It won't.
Voltage must increase until it reaches a level sufficient to ionize the air between the electrodes. If that level is never reached, electrical current in one electrode will never flow to the other one. That is why spark plugs need a transformer (coil) in the first place, otherwise you could simply run your car with the distributor connected directly to the alternator.
Bill Robertson



...you should be guessing that since stock engines run with worn plugs and wide gaps, spark must be jumping across the worn/wider gaps.
So I ask you, "How the hell do you think spark is going to jump across a wider spark plug gap if you don't increase voltage?"It won't. Put a timing light on the plug -- it won't be firing.
Bill Robertson

[Well, that wasn't so bad...all of the cut and paste reminded me of working for Equifax...at least it wasn't Assembler.]

========

Well, since I'm already here, again:

RE:

No, you did that, as far as I am concerned, when you said t...That invoked the performance/HP-emission crap you kept ignoring from most everyone.
But I see below you are trying to sneak it in now -- Along with your conclusions on their conclusions.
I wonder how long it will take you to pick on a another typo, verbiage, insignificant piece, etc, and start of on another tangent or explode with more extraneous truths.
( It didn't take long, the very next post in the thread: )


Not to point out the obvious, but I *DID* mention emissions (and fuel economy) in the very first post of this thread, as a quote from an even earlier post of mine in other thread....
Bill Robertson
Yeah, you *DID* mention it, but saying, ...


In a low compression engine, like the stock DeLorean PRV, the mixture is harder to ignite. Leaning the mixture out for fuel economy and emissions exacerbates the situation.
...does not remotely address '"performance" including HP & Emissions', whether you did when you said a hotter coil alone would increase it, or your emissions (to name but a few).
Just another extraneous truth.
And, yeah it was where you quoted from an even earlier thread, YOURSELF (http://dmctalk.org/showthread.php?1277-Ignition-coil-questions...&p=15048&viewfull=1#post15048)! :hysterical:
You *ARE* getting sneaky! I'll have to try that one...

=====


Now that's how to mutli-quote! Thanks Martin!

I was proud of this post (http://dmctalk.org/showthread.php?1334-High-Energy-Ignition-(HEI)&p=17009&viewfull=1#post17009) until now.:huh:

[cineman]

Funny then that the numbers cast into DeLorean parts like the intake manifold, sump and more are actually Renault part numbers.... even the camshaft numbers Bill has posted in his Volvo literature are traceable Renault numbers....!

Yeah, check out Renault's performance today....

Yes, you are right: every part number on the PRV is native Renault (77...79 etc )
I would like to really know the economy partecipation of all the members of the PRV association at the time: for me appear that Renault did quite everything and got the more.
What i was meaning is that the parts on Delorean engine, at least the top end, was used directly just by Volvo at the age. heads, pistons... just Volvo had the 2.8lt engine at the time, renault got it more later.

Also, this is a scan of the rare document i got. The contract for the engines from Delorean was made directly from Renault, this was confirmed by me by some french guy wich visited the Douvrin factory and know some of the old manager and also by Nich Sutton in N.Ireland, who told me that Renault was the only company to get all the money after the closure of the delorean factory, just because they signed the contract in some way directly with JZD. This is the Renault documents "PR" "Piece de Rechange" for the Delorean engine and parts from them. I have 32 page on this.

Look what i was talking about: the first 126 engines got some different parts, like the ignition distributor "017" wich was directly used on the Volvo 264... and than came the quiter "023" we have. And there are lot of other difference in cams, heads, pistons...
Well.. i find it really exciting, dont ? Would be interesting to confirm it by seeing some of the Proto car engine and checking the numbers...

4736

4737

[DCUK Martin]

Now that's how to mutli-quote! Thanks Martin!



http://t3.gstatic.com/images?q=tbn:ANd9GcSe1kAsPVNVxRlss3QnhVijNZu-IYq5yZukpUqMFRbgGodV_BLJhA

It's really easy, just quote and reply as normal to each post, then instead of clicking on "submit", cut and paste it into Notepad. Keep doing that with every repply, and cut back out of Notepad into the last one. Simples!

http://4.bp.blogspot.com/_5kSia53SdlI/TH6QwKVjqrI/AAAAAAAABLU/9IBsi_1hG8s/s1600/Simples.jpg



Because real engineers, who build ignition systems for a living, disagree with you?

Bill, they are talking about the spark duration required to ignite the mixture, not the power required for the spark to fire. NOT THE SAME THING!

BTW just for once, let me say it: I -am- a qualified professional engineer. Twice over in fact.



The plug will spark at whatever voltage is sufficient to bridge the gap, no matter what the 'maximum output' voltage of your coil is, no matter what your compression ratio is, and no matter what your A/F is.

Let's not confuse Bill. I agree with you entirely that the voltage will stop climbing the moment it's reaches the required level. However, just to be clear for Bill's sake, increased pressure reaises that level.

[Ron]

Let's not confuse Bill. I agree with you entirely that the voltage will stop climbing the moment it's reaches the required level.Why didn't someone tell me!!! I must have told him 10 times in as many threads...
I'm sorry Bill.

[content22207]

The converse is also true: if your plug gap is too wide, maximum coil output voltage will be reached before it is sufficient to jump the gap, and the plug won't fire. If you don't believe me, just gap your plugs .05" and leave the rest of ignition stock, then try to drive the car.

Stock DeLorean ignition is incapable of reliably jumping .05" plug gaps -- period.

All the theory in the world isn't worth two cents when your engine is misfiring all over the place.

Can I hear an "Amen" from anyone who has actually tried to do so, versus the armchair theorists.

Bill Robertson
#5939

[stevedmc]

The converse is also true: if your plug gap is too wide, maximum coil output voltage will be reached before it is sufficient to jump the gap, and the plug won't fire. If you don't believe me, just gap your plugs .05" and leave the rest of ignition stock, then try to drive the car.

Stock DeLorean ignition is incapable of reliably jumping .05" plug gaps -- period.

All the theory in the world isn't worth two cents when your engine is misfiring all over the place.

Can I hear an "Amen" from anyone who has actually tried to do so, versus the armchair theorists.

Bill Robertson
#5939

YEAH, I tried it and it didn't work.

YEAH, I told them that.

YEAH, they won't listen.

[DCUK Martin]

The converse is also true: if your plug gap is too wide, maximum coil output voltage will be reached before it is sufficient to jump the gap, and the plug won't fire. If you don't believe me, just gap your plugs .05" and leave the rest of ignition stock, then try to drive the car.

....

All the theory in the world isn't worth two cents when your engine is misfiring all over the place.

So here's a novel thought:

Leave it alone

It's perfectly reliable working as designed. Point made. :thankyou:

[content22207]

Stock DeLorean ignition is functional (most of the time), not optimal.

I prefer optimal performance over merely functional performance, just like nearly every other automobile manufacturer in 1981 (and since, to this very day), so:

I upgraded my ignition to 1981 (and since, to this very day) General Motors standards.
I upgraded my ignition to 1981 (and since, to this very day) Ford/AMC standards.
I upgraded my ignition to 1981 (and since, to this very day) Chrysler standards.
I upgraded my ignition to 1981 (and since, to this very day) Toyota standards.
I upgraded my ignition to 1981 (and since, to this very day) Datsun (Nissan) standards.
I upgraded my ignition to 1981 (and since, to this very day) Subaru standards.
I upgraded my ignition to 1981 (and since, to this very day) Honda standards.
I upgraded my ignition to 1981 (and since, to this very day) Mitsubishi standards.

The best part of my upgrade: the high winding ignition coil that made it possible cost *LESS* than a Bosch Blue coil.

Icing on the cake: My coil was Made in USA by an American corporation, not Made in Brazil by a foreign owned corporation (Bosch coils are Made in Brazil now).

When you get right down to it, I wanted my PRV to perform at least as well as a 1988 and later PRV, so I upgraded my ignition slightly beyond the same specs Chrysler used on the Premier 3.0.

Bill Robertson
#5939

[sean]

Stock DeLorean ignition is functional (most of the time), not optimal.

I prefer optimal performance over merely functional performance, just like nearly every other automobile manufacturer in 1981 (and since, to this very day), so:


Got a follow up question about this in you carb thead (http://dmctalk.org/showthread.php?95-Ask-Bill-about-carbing-a-DeLorean-and-other-K-Jet-Carb-tangets).

[content22207]

The fact that nearly every automobile manufacturer was already using HEI in 1981, and the fact that they have continued to use HEI to the present day, evidences two facts:
1) HEI was not a passing fad -- when DeLoreans were new in the showroom it was already established as the ignition standard that has never gone away
2) HEI is independent of fuel delivery -- manufacturers have used it on carbureted and electronically fuel injected engines alike

Bill Robertson
#5939

[dn010]

What did Volvo use on their K-jet setups in the 80's?

[Ron]

I wanted my PRV to perform at least as well as a 1988 and later PRV, so I upgraded my ignition slightly beyond the same specs Chrysler used on the Premier 3.0.Let me get this right.
Although you seem to imply it, you don't actually claim it here, so I ask, does this mean you accomplished what it seems you set out to do -- That is, does your PRV meet or exceed the power output and have as clean or cleaner emissions than those of the average, 1988 and later, factory equipped PRV stock vehicles?

[DCUK Martin]

All odd fires, Volvo, Renault, Peugeot have the same setup.

[content22207]

Even fire is where ECU's diverge. Volvo went with a redesigned Bosch ECU for the B280 (still .028" plug gap). Renault/Chrysler went with a Renix (Bendix?) unit for the 3.0 (Autozone shows .044" plug gap, other online sources show .030-.035").

Bill Robertson
#5939

[DCUK Martin]

In the 3 litre turbo PRV, the most powerful production variant (in fact de-tuned so as not the break the trasmission). the plug of choice is the NGK BKUR7ET.

I'll let Bill work out what the "7" in the part number means.

[content22207]

You find the most interesting things in syndicated print:

5034

Bill Robertson
#5939

[DCUK Martin]

So now I've gone to the effort of enhancing that image so I could read it at all, can you tell me one simple thing:

What's your point?

Modern high compresion, faster revving, higher specific-power engines may require a higher voltage to jump the spark gap, and that gap may, or may not, be wider than 0.7mm

This does not apply to the DeLorean engine whose system works just fine if it's healthy.

[content22207]

Incorrect: higher compression ratios can effectively combust with lower spark energy than lower compression ratios.

As a forced induction user, who publicly claims that his engine runs better with stock ignition than HEI, you should know that.

Bill Robertson
#5939

[DCUK Martin]

Don't go putting words into my mouth, Bill. I said that my turbo engines successfully run with a stock coil whereas attempts to use a higher "performance" unit resulted in misfire. The plugs I use are those used by the Alpine crowd, both of which are cold plugs with a 0.7mm gap.

The voltage required to jump the gap of a spark plug increases with combustion chamber pressure. Prove me wrong.

BTW lets not forget that a few pages back you claimed that inductive ignition has been obsolete since the early 80s...

[content22207]

Prove me wrong.

Pages 61 and 62 of the afore mentioned SAE paper are a good start (are you *EVER* going to read that thing?).

Or, as any student of American automotive history will tell you, as compression ratios dropped from the 1960's into the 1970's, misfiring became an increasing common problem (exacerbated by leaner fuel mixtures). That is one reason American manufacturers adopted HEI across the board in the 1970's.

Don't forget that the DeLorean PRV runs in North American guise (low compression, lean mixture).

Bill Robertson
#5939

[DCUK Martin]

You have AGAIN repeated that the DeLorean engine runs lean. WRONG. The DeLorean engine, as with every engine with a 3-way catalyst, is designed to run at stochiometry (perfect fuel/air ratio) for 99% of the time.

I can't even find the link to that paper now. Please, go ahead and quote the exact passages that back up your assertion.

It is a physical fact that resistivity of a gas increases with pressure. I don't know how you think you can ignore sh!t like this... it is first principles stuff.

[content22207]

Yay! Martin is going to read two pages of the paper!

5040 5039

(Remember: 7:1 is *LOWER* compression than 11:1).

Bill Robertson
#5939

[DCUK Martin]

You are confusing flame propagation with spark energy.

Those pages talk about the requirement for longer spark duration in lower compression and "lean burn" engines.

The DeLorean engine does not run lean, nor is it a particularly low compression engine.

[content22207]

Compared to a Eurospec PRV, the North American version is low compression and lean burn.

You need to look at HEI in its historical context. The 1972 Clean Air Act changed the North American automobile manufacturing landscape radically. For example, in 1972 manufacturers dropped compression on every single engine they manufactured. Whereas 10:1 to 11:1 compression ratios were very common in the 1960's, you could not buy a new production vehicle with an engine with higher than 8.5:1 compression after 1972 -- period. It was a radical change, noted in all the automobile magazines of the time. Automobile manufacturers also started jetting their carburetors leaner, partly for emissions and partly for fuel economy -- especially after the 1973 oil crisis.

HEI was developed to optimize combustion in the low compression lean burn North American engines of the 1970's, of which the DeLorean PRV definitely is one.

And of course, with the exception of turbocharging. engines have continued to run in low compression lean burn guise ever since, which is why ignition components such as coil voltage and spark plug gap never went back to their breaker point specs. Regarding turbocharging, which does consume more fuel and produces more pollution, remember that manufacturers have to meet what is known as Corporate Average Fuel Economy -- their entire fleet meets governmental targets. Turbocharged models are offset by econo models. For every Mustang there are multiple Foci. For every Camaro there are multiple Volts. Etc. Forced induction is the exception, not the rule.

Bill Robertson
#5939

You have to read the entire page, Martin:

5051

Bill Robertson
#5939

[DCUK Martin]

(typing this through gritted teeth)

Get your terminology right. "Lean Burn" refers to very specific, very rare types of spark ignition piston engines which are designed to run at AFRs greater than 14.7:1.

The PRV, whatever flavour, is not one of them.

Your document, and those parts you have underlined proves nothing with regard any advantage on the DeLorean engine.

Bottom line, there is nothing wrong with the DeLorean ignition system as designed!


Compared to a Eurospec PRV, the North American version is low compression and lean burn.


No, it has a lower static compression ratio and runs closed loop fuel control meaning it stays around stochiometry. This is not "lean"!




HEI was developed to optimize combustion in the low compression lean burn North American engines of the 1970's, of which the DeLorean PRV definitely is one.
:boxface:



Regarding turbocharging, which does consume more fuel and produces more pollution,


Bollocks. Per hp, a forced induction engine is actually cleaner and more efficient than a naturally aspirated equivalent. Forced induction increases the volumetric flow of the engine and a turbocharger uses what would otherwise be wasted energy to do it.



Forced induction is the exception, not the rule.


For now.... but trust me, in a few years you'll see smaller and smaller engines with larger and larger, more elaborate turbochargers, mirroring what has happened with diesels over the past 20 years.

[Agent Smith]

Through gritted teeth indeed. I normally lurk but the amount of misinformation and ignorance in the thread by this guy is appalling.

[Ron]

Through gritted teeth indeed. I normally lurk but the amount of misinformation and ignorance in the thread by this guy is appalling.
He has all of the information...he just chooses to ignore or re-interpret it.

=====


Compared to a Eurospec PRV, the North American version is low compression and lean burn.
And compared to a bean can full of burning gasoline it isn't! -- That's not a DeLorean engine either!



You need to look at HEI in its historical context.
OK !!!

:bootyshake:......:dork: You supplied the information to prove yourself wrong!

Lets look at the conversation between the experts, Ray and Tom, that YOU posted.
The very first thing YOU underlined is where Ray is clearly referring to "cars these days" and "for the past decade or so", when he said "Right." to Tom!
Ray continues with, "Now that spark plugs need much higher voltages for more complete combustion (and therefore fewer emissions)," -- 1981 is not "Now", but over three decades earlier!

As already said, the other papers you posted clearly show engineers were aware of all this, as do the papers they refer from the 1960s! DeLorean would have used one of many other coils readily available in those days -- There is nothing wrong with the stock coil on a stock DeLorean. And again, changing the coil alone does not change the resistance from the coil to the plug, so the energy used will remain the same! It uses what it "wants" NOT what you "push" through it.




The 1972 Clean Air Act changed the North American automobile manufacturing landscape radically. For example, in 1972 manufacturers dropped compression on every single engine they manufactured. Whereas 10:1 to 11:1 compression ratios were very common in the 1960's, you could not buy a new production vehicle with an engine with higher than 8.5:1 compression after 1972 -- period. It was a radical change, noted in all the automobile magazines of the time. Automobile manufacturers also started jetting their carburetors leaner, partly for emissions and partly for fuel economy -- especially after the 1973 oil crisis.
HEI was developed to optimize combustion in the low compression lean burn North American engines of the 1970's, of which the DeLorean PRV definitely is one.
According to the DeLorean Workshop Manual (A:01:01), Vehicle Specification Data: Compression ratio = 8.8:1
According to the DeLorean Workshop Manual (A:02:01), Engine Tuning Data: CO = 1%
Facts all of your wild comparisons and historical facts can not change:
8.8 > 8.5
1% = 0.01
CO can be equated to air/fuel ratio -- 0.01 percent CO is equivalent to 14.7:1 air/fuel ratio.
14.7:1 is Stoic, neither rich NOR lean!

[DCUK Martin]

8.8 > 8.5


Darn, missed that one :rofl:

Anyway static CR tells you nothing about the actual volumetric compression ratio under load. It's only useful for comparing engines with identical valve timing, it gives no absolute reference point.

[content22207]

1) Trend: If lower voltage ignition jumping smaller plug gaps performed better than higher voltage ignition jumping larger plug gaps, manufacturers would have gone back to them. They didn't. Manufacturers went to ever higher voltages and ever larger plug gaps. It is common now to see COP voltages as high as 100,000 volts and plug gaps as large as .08".

2) PRV specific: Renault itself jetisoned Bosch ignition, and the small plug gaps it can support, and went to higher voltage ignition and larger plug gaps on the 3.0 redesign.

Is it possible Martin had problems with his high winding coil simply because he wired the poor thing up backwards? For some reason that seems to be an endemic mistake among DeLorean owners. As I've said all along, if you want HEI performance, you need a complete HEI setup, including correct polarity in/out of the coil.

Bill Robertson
#5939

[DCUK Martin]

1) Trend: If lower voltage ignition jumping smaller plug gaps performed better than higher voltage ignition jumping larger plug gaps, manufacturers would have gone back to them. They didn't. Manufacturers went to ever higher voltages and ever larger plug gaps. It is common now to see COP voltages as high as 100,000 volts and plug gaps as large as .08".


The optimum plug gap depends on a whole heap of variables. Wider gaps with higher voltages are not simply "better". There are modern cars with 0.7mm gaps just like there're older cars with larger gaps.



2) PRV specific: Renault itself jetisoned Bosch ignition, and the small plug gaps it can support, and went to higher voltage ignition and larger plug gaps on the 3.0 redesign.

No they didn't. To say Renault "jetisoned" Bosch on their inability to support larger plug gaps is frankly laughable.

The switch from Bosch to Renix was more to do with politics and Renault's deal with Bendix as they moved towards EFI.

All the PRV cross-ref plugs I can find are gapped at 0.6-0.7mm, same as DeLorean. (Renault 25 V6, Safrane V6, Espace V6, Laguna V6, Alpine A610 (turbo), Alpine GTA V6 turbo - all pre-1995. Feel free to look 'em up yourself).

[content22207]

The optimum plug gap depends on a whole heap of variables

5054


Feel free to look 'em up yourself).

5053

Bill Robertson
#5939

[Ron]

1) Trend: If lower voltage ignition jumping smaller plug gaps performed better than higher voltage ignition jumping larger plug gaps,
STOP right there!
More facts you can not change:
1. Larger plug gaps (with or without higher voltage ignition) is not changing the coil alone!

2. If you believe that to be true then you must accept the converse:
If higher voltage ignition jumping larger plug gaps performed better than lower voltage ignition jumping smaller plug gaps DeLorean manufacturers would have went with them. They didn't.
(Remember 'your' papers prove they were aware of all this in the 1960s).



2) PRV specific: Renault itself jetisoned Bosch ignition, and the small plug gaps it can support,
Stop right there!
Look at what you posted! :bootyshake:......:dork: The Bosch ignition CAN support the small plug gaps! :thankyou:


[Mods, would it be possible to supply a smiley with a appropriately sized anal orifice]

[content22207]

Look at what you posted! The Bosch ignition CAN support the small plug gaps!

I have never denied that Bosch ignition (coil) can support small plugs gaps -- that is *ALL* it can support. What the Bosch Blue coil can not support is HEI caliber plug gaps. That is why every vehicle running a Bosch Blue coil, including DeLoreans, has small plug gaps -- that is the best they can do.

Bosch ignition is adequate. It will make gasoline explode (most of the time). It is not performance ignition, even insofar as contemporary Mustang or Camaro ignitions. If you want performance ignition in your DeLorean:
1) You need a proper high winding coil
2) You need to increase primary voltage into that coil
3) You need to widen plug gaps

Every owner I know who has actually tried this, versus merely pontificating theories alone, has been thrilled with the results. I am not aware of anyone who has tried true HEI (more than just Martin's potentially backwards wired coil alone) and gone back to the stock setup.

Bill Robertson
#5939

[DCUK Martin]

I have never denied that Bosch ignition (coil) can support small plugs gaps -- that is *ALL* it can support.

So how does it manage in my turbo engines at a bar of boost? The gap's the same, resistive Bougicord leads, conventional (albeit different) distributor, getting on for twice the combustion chamber pressure.

The fact is that you have no evidence that the Bosch system *can't* support a greater plug gap, have you?

...and there's no point 'cos it ain't necessary.

I have no idea why AMC felt the need to specify a larger plug gap. I can only presume a man with similar "experience" as you was in charge of specifications. You said Renault, and Renault didn't increase plug gaps.

[DCUK Martin]

more than just Martin's potentially backwards wired coil alone

While nobody's infallible, Bill, I've never wired a coil up backwards on any of my 7 DeLoreans, nor any of my customer's DeLoreans. Perhaps you should try fitting capacitive ignition to yours. After all, all cars since the 1980's have used it.... (according to you)

[opethmike]

Every owner I know who has actually tried this, versus merely pontificating theories alone, has been thrilled with the results. I am not aware of anyone who has tried true HEI (more than just Martin's potentially backwards wired coil alone) and gone back to the stock setup.

Bill Robertson
#5939

Have any of these users ever actually PROVEN that there is a performance benefit? That is, had dyno testing done? Otherwise, there is only anecdotal evidence, and that is meaningless.

[content22207]

Please take all arguments for stock ignition to this thread: http://dmctalk.org/showthread.php?1593-Advantages-of-Stock-Ignition&p=19605#post19605.

Bill Robertson
#5939

[Ron]

I have never denied that Bosch ignition (coil) can support small plugs gaps -- that is *ALL* it can support.
:shock: STOP right there!
You fully imply that when you say one will gain performance by changing the coil (HEI) alone.
Damn Bill, if I posted every time you argued against that not being the case, the system would crash again! -- It is exactly what most of the BS arguments have been over!




If you want performance ignition in your DeLorean:
1) You need a proper high winding coil
2) You need to increase primary voltage into that coil
3) You need to widen plug gaps

Every owner I know who has actually tried this, versus merely pontificating theories alone, has been thrilled with the results. I am not aware of anyone who has tried true HEI (more than just Martin's potentially backwards wired coil alone) and gone back to the stock setup.

Theories? What theories?

There are plenty of coils that have a winding ratio high enough to omit #2.

Owners trying 'that' is not the same as "changing the coil alone on a good running stock Delorean". Not to mention fixing what was really wrong that caused them to do 'that' in the first place.

Who would replace a new "more than adequate HEI setup" with an old, adequate set up? :umm:

[DCUK Martin]

Have any of these users ever actually PROVEN that there is a performance benefit? That is, had dyno testing done? Otherwise, there is only anecdotal evidence, and that is meaningless.

...and as I'm always careful to point out, my position is from a properly working original system. Not a dodgy in-need-of-maintenance original system replaced with something Bill would approve of which results in a leap in performance.


Please take all arguments for stock ignition to this thread:


Why? So we leave you alone on this thread with only your soap box for company?

[content22207]

It was wrong of me to speak for any other owners running HEI. They are all grown intelligent men, perfectly capable of speaking for themselves. I will henceforth speak only of my own experiences.

I am running the following HEI setup on #5939:
- .25 ohms resistance on the coil supply (yields 12.5 volts into the coil when the alternator is charging)
- A Pertronix 40,000 volt coil
- Standard cap and rotor (one one my goals is to eventually bypass the 5K ohm resistor in the rotor button)
- MSD spiral wound distributor lead and plug wires
- AC Delco plugs, gapped ~.05"

This ignition setup has given me excellent speed and fuel economy performance in real world driving experience.

I am proud to say that my coil and distributor lead/plug wires were Made in USA.

Bill Robertson
#5939

[Ron]

So what Bill, you have went from ignoring your claim that replacing the stock coil alone will increase performance, to claiming you never said such a thing?

Isn't all of this getting old even to you? (My excuse is that I am on a mission.)

[opethmike]

This ignition setup has given me excellent speed and fuel economy performance in real world driving experience.


You keep saying that over and over again, but can you actually PROVE this? Seat of the pants is not proof. Saying that other people that have driven your have stated it feels faster is not proof. (By the way, I sincerely thank you for letting me drive your car, that was generous, and I appreciate that, as well as enjoyed the drive)

That's my only issue that I have whatsoever with anything you say about supposed performance improvements to these cars. I have never seen you provide concrete proof of any actual gains. Show me/us dyno numbers, drag strip times, etc if you are going to be so firm about them being true improvements.

[content22207]

This is how coil input voltage on my DeLorean compares to several of my other vehicles (except for the 1969 engine, which has been transplanted into a 1979 vehicle, primary wiring is stock on all):

"1969" Lincoln, 460 inch Windsor engine, Pertronix coil, Pertronix ECU, MSD spiral wires, .044 inch plug gaps:
5060

1978 Lincoln, 400 inch Cleveland engine, Pertronix coil, Duraspark ECU, MSD spiral wires, .044" plug gaps:
5056

1984 F-250, 300 inch Lima engine, Pertronix coil, Duraspark ECU, MSD spiral wires, .044" plug gaps:
5057

1985 F-150, 300 inch Lima engine, stock coil, TFI ECU, MSD spiral wires, .044" plug gaps:
5058

1988 F-150, 302 inch Windsor engine, stock coil, TFI ECU, MSD spiral wires, .044" plug gaps:
5059

Bill Robertson
#5939

Correction: my 1979 Lincoln (1969 engine) wiring harness looks to be original to the car. Obviously there is a resistance difference on the coil supply between it and my 1978 Lincoln (other than the engine, they are sister automobiles). Don't know if the resistance wire was replaced at some point, or if this is a factory spec difference between 1978 and 1979 model years (the fact that my 1984 truck only runs 10.5 volts makes that seem unlikely).

Bill Robertson
#5939

[opethmike]

Thanks for ignoring me twice, Bill.

[DCUK Martin]

Proves....?

[content22207]

My DeLorean is currently in hover mode:

5062

so I didn't feel like starting it -- this is a primary ignition reading with the battery charger emulating the alternator:

5063

(The alternator jumps it up to 12.5 volts).

As you can see, my DeLorean's ignition is very comparable to my other vehicles' ignitions. It is dramatic improvement over the anemic 6-8 volts primary of a stock ignition. This is how I accomplish it:

5064

Remember that I am running a Pertronix coil, not a Bosch Blue coil. The Bosch Blue coil is reportedly unable to handle more than 6-8 volts for extended periods of time. Do not do this on your own car unless you have exchanged the Bosch Blue coil for a proper performance coil.

As you can probably guess by now, Pertronix is my coil of choice.

I run MSD spiral wires because they are made of real wire -- much more durable than imitation wires. You can actually solder to MSD wires (John Hervey solders his terminals). Insulation jacket is 20% thicker too. You do pay dearly for a set of MSD wires, but you only pay once. They are truly lifetime wires.

Higher primary voltage, and higher coil winding ratios, allow me to open my plug gaps up to ~.05", which of course yields easier starting, better acceleration, reduced emissions, and lower fuel consumption. I am very pleased with the results. If my car had wheels on it, it would totally spank a stock DeLorean.

Bill Robertson
#5939

[opethmike]

Why do you keep ignoring questions regarding actual proof of your claims?

[sean]

Why do you keep ignoring questions regarding actual proof of your claims?

Why are you guys surprised by this? This is classic Bill. I think he gets his jollies by ignoring you guys the way he does.

[opethmike]

Why are you guys surprised by this? This is classic Bill. I think he gets his jollies by ignoring you guys the way he does.

You're right Sean. I'm done with this silliness.

[content22207]

I wonder if anyone is willing to argue that high voltage ignition (the industry standard) is harmful or detrimental? Arguments raised thus far have not been that HEI is bad, but rather that low voltage ignition is good enough.

If no one is willing to argue that HEI (the industry standard) is bad, the question isn't "why convert to HEI?" The question is "why not convert to HEI?"

A Pertronix coil costs *LESS* than an Bosch Blue coil ($39.95 vs $69.95). It also is Made in USA (Bosch coils are Made in Brazil now). The resistor grid is already in place -- all you need do is add a jumper (less than a dollar) and move the terminals around. You can run HEI through Bosch or Bougicord wires just fine (the problem with Bosch and Bougicord wires isn't their internal resistance but their internal construction, and their thin insulation jackets).

An owner can convert to HEI for slightly more than $40. It is one of the LEAST expensive things you can do to a DeLorean.

Bill Robertson
#5939

[stevedmc]

The question is "why not convert to HEI?"

The answer is, "So you don't have to listen to Ron and Martin's crap."

[content22207]

Surely Ron and Martin would not let their feelings towards me as an individual interfere with at least trying HEI on their own cars, just to see first hand whether they like it or not.

I tried both stock ignition and HEI in real world use (not theoretically), and found that I like HEI better.

Bill Robertson
#5939

One of the "characteristics" (to keep things civil, we won't call it an "advantage" or "disadvantage") of HEI is the ability to ignite the fuel/air mixture closer to TDC and still get complete combustion.

There is a school of thought that igniting the fuel/air mixture too soon can be counterproductive because the expanding explosion will push against the rising piston.

My engine is timed 10 degrees BTDC, not 13 degrees BTDC (a stock DeLorean timing scale is superimposed next to mine for comparison):

5088

In conjunction with my ignition distributor, which clearly differs from a stock DeLorean unit:

5089

HEI definitely allows me to light my mixture closer to TDC and still get complete combustion.

Yet another reason why my DeLorean is faster than a stock DeLorean.

Bill Robertson
#5939

BTW: My block itself is a pedestrian low compression PRV, same as DeLorean. Not only does its cylinder compression read ~150 PSI (despite what Martin says, you *CAN* tell a European block from a North American one with a compression test -- my Renault Z7V block reads ~170 PSI), but I run 87 octane through it with no detonation problems whatsoever.

Bill Robertson
#5939

[DCUK Martin]

My DeLorean is currently in hover mode:



Mine's better:
http://dmctalk.org/attachment.php?attachmentid=5091




Remember that I am running a Pertronix coil, not a Bosch Blue coil. The Bosch Blue coil is reportedly unable to handle more than 6-8 volts for extended periods of time. Do not do this on your own car unless you have exchanged the Bosch Blue coil for a proper performance coil.



You still have no clue when it comes to basic electrics! You could cheerfully zap a couple of thousand volts through the coil and it wouldn't hurt it. It's current that matters, and it's current that determines the performance of the coil!




I run MSD spiral wires because they are made of real wire -- much more durable than imitation wires. You can actually solder to MSD wires (John Hervey solders his terminals). Insulation jacket is 20% thicker too.


Can I just ask if your Hi Fi speakers have arrows on them? I bet you're a firm believer in directional speaker cable...



which of course yields easier starting, better acceleration, reduced emissions, and lower fuel consumption.


Of course it does. It also reduces tyre wear, aerodynamic drag and makes your headlights shine brighter. The unfortunate side effect is that you have to carry a huge pile of bullshit around and spout it at every opportunity...



There is a school of thought that igniting the fuel/air mixture too soon can be counterproductive because the expanding explosion will push against the rising piston.

REALLY?! You don't say.... :ehh:



My engine is timed 10 degrees BTDC, not 13 degrees BTDC (a stock DeLorean timing scale is superimposed next to mine for comparison):

That's just the advance at idle and is standard on 013 distributors. It tells you nothing about the shape of the curve, only that it starts at a slightly lower level of advance. It runs more advance only a couple of thousand RPM later, so by your own ill-conceived argument, you should be running at less than 10 degrees BTDC. Let's see how your performance goes when you try it, shall we?


The answer is, "So you don't have to listen to Ron and Martin's crap."

Did you believe Carl Tilley too?

[content22207]

Despite having the same basic engine block, my DeLorean is notably faster than a stock DeLorean. Every single person who has driven it (As Mike Lund can attest, I loan the car out readily) comments on its performance. Overall it is a cumulative effect of:
- Carburetion, especially via a single plane intake manifold
- High Energy Ignition
- True dual exhaust
- Make believe catalytic converters (tubing passes right through them, so there is no volumetric change in velocity)

Live with it.

Bill Robertson
#5939

[opethmike]

Every single person who has driven it (As Mike Lund can attest, I loan the car out readily) comments on its performance.
Bill Robertson
#5939

Yup, that is pretty cool of you.

[content22207]

Was it faster than stock?

Bill Robertson
#5939

[opethmike]

It felt quicker - but I hadn't driven my DeLorean in six months at that point, so I didn't really have a good basis of comparison. What I chiefly notice (and really dug!) was the loud, gnarly exhaust.

[DCUK Martin]

Despite having the same basic engine block, my DeLorean is notably faster than a stock DeLorean. Every single person who has driven it (As Mike Lund can attest, I loan the car out readily) comments on its performance.

...and back on page 4 of this thread, I wrote:


I've actually never argued that Bill's car isn't faster than a stock DeLorean. It almost certainly is. The Alpine GTA Atmo with slightly different cams, ignition timing (advance weights) and a twin Solex carb setup but otherwise identical transmission and ignition system is a heap quicker than a DeLorean - 156hp IIRC. They didn't have the mpg or emissions figures to hit that DMC did. I'm pretty sure Bill's current setup wouldn't meet those either.

:thankyou:

[DCUK Martin]

Live with it.



Prove your ignition system made a difference. Oh! You can't. Live with that and stop posting irrelevant crap skirting around the simple fact that you can't.

[content22207]

If Martin were just to buy himself a silk mankini too, it would take our relationship to a whole new level....

"Carbs rock -- high five!"
"K-Jet rocks too -- high five!"
"Forced induction rocks -- high five!"
"American big blocks rock too -- high five"
"Crappy Lotus engineering rocks -- high five"
"Ford rocks too -- high five"
"I've run out of things to high five"
"Let's high five running out of things to high five"

Bill Robertson
#5939

[Ron]

First of all (your earlier post)- I haven taken any of your BS personal and could imagine all of us getting blasted and having a hell of a time. (Maybe one weekend here in the mountains so we won't get arrested). BUT, the evil overlord of alternative DeLorean fuel delivery SUCKS!

Back to you post above-
If that's all it takes for you to quit prefacing every other #ucking post with a turd in the pool and not offering even a "yes" or "no" TO SERIOUS QUESTIONS, I'll trade in the seafoam swim suits for mankinis (or you can have one of them) -- I'm keeping the girls. But you all have to promise not to wear them around me!!!

[DCUK Martin]

If Martin were just to buy himself a silk mankini too, it would take our relationship to a whole new level....

"Carbs rock -- high five!"
"K-Jet rocks too -- high five!"
"Forced induction rocks -- high five!"
"American big blocks rock too -- high five"
"Crappy Lotus engineering rocks -- high five"
"Ford rocks too -- high five"
"I've run out of things to high five"
"Let's high five running out of things to high five"

Bill Robertson
#5939

Huh? :dunno:

[sean]

Huh? :dunno:

.

Why are you guys surprised by this? This is classic Bill. I think he gets his jollies by ignoring you guys the way he does.

[content22207]

I think Houston should license silver metallic DMC mankinis to Adam & Eve, then someone can start a thread in the Open Discussion Forum titled For those considering wearing their Delorean Mankini:

"The material used to simulate stainless is unforgiving. It creases, and cuts...."

Bill Robertson
#5939

[sean]

Ugh, he went from not answering questions to answering every question with "Mankini". I think I liked it better before.

[stevedmc]

Ugh, he went from not answering questions to answering every question with "Mankini". I think I liked it better before.

Be thankful he hasn't incorporated the picture into a new signature.

[sean]

So it's clear Bill is not going to address any questions about his claims seriously so this thread has run it's course.