Spark plug discussion***Split from engine car reassembled thread***

[sean]

Why +4's? I've heard nothing but bad stuff about those plugs, especially when used in a D. Bosch silver's work just fine. The only function of a plug is to create an arc. It only needs one tip to do it!

Andy

I've only heard and experienced bad things with the single prong platinums, I've had no issues with the +4's. Personally installed them on well over 10 cars without out issue, that should be good enough stats for Steve to use them. I will say this, the OEM Bosch, silver I believe, are great too.

[stevedmc]

I've only heard and experienced bad things with the single prong platinums, I've had no issues with the +4's. Personally installed them on well over 10 cars without out issue, that should be good enough stats for Steve to use them. I will say this, the OEM Bosch, silver I believe, are great too.

Nonsense.

I'm not saying the plugs are why his car won't start but the concept with those plugs are stupid. I've actually seen better gas mileage on my Geo Metro running a set of cheap NGK plugs that were properly gapped.

The concept of the +4 plugs are stupid in my opinion. The spark will only travel across one of the prongs and not all four. I've never had a problem with properly gapped plugs. What I have had a problem with is plugs that weren't gapped to the correct setting.

[sean]

Nonsense.

I'm not saying the plugs are why his car won't start but the concept with those plugs are stupid. I've actually seen better gas mileage on my Geo Metro running a set of cheap NGK plugs that were properly gapped.

The concept of the +4 plugs are stupid in my opinion. The spark will only travel across one of the prongs and not all four. I've never had a problem with properly gapped plugs. What I have had a problem with is plugs that weren't gapped to the correct setting.

Never argued concept or gas mileage. Just that I've never had issue with a car running poor with +4s.

[Bitsyncmaster]

Nonsense.

I'm not saying the plugs are why his car won't start but the concept with those plugs are stupid. I've actually seen better gas mileage on my Geo Metro running a set of cheap NGK plugs that were properly gapped.

I've seen exactly the opposite on a few cars I've run +4 on. Better MPG with the +4s.

[82DMC12]

Nonsense.<br />
<br />
I'm not saying the plugs are why his car won't start but the concept with those plugs are stupid. I've actually seen better gas mileage on my Geo Metro running a set of cheap NGK plugs that were properly gapped.<br />
<br />
I've seen exactly the opposite on a few cars I've run +4 on. Better MPG with the +4s.

And how can this be explained? I see no logical reason + 4's would help anything unless one of the tips break... You still have 3 left :-P

Sent from my DROID BIONIC using Tapatalk

[stevedmc]

I've seen exactly the opposite on a few cars I've run +4 on. Better MPG with the +4s.

I've never compared the bosch fancy smancy ones to a plain old spark plug on my Delorean but on my Geo Metro I did find that I get better gas mileage with plain old NGK plugs.

Are you sure you aren't comparing 4 prong plugs to improperly gapped regular plugs?


And how can this be explained? I see no logical reason + 4's would help anything unless one of the tips break... You still have 3 left :-P

The only think I can think of is the regular plug was either old or wasn't properly gapped.

[Bitsyncmaster]

And how can this be explained? I see no logical reason + 4's would help anything unless one of the tips break... You still have 3 left :-P

Sent from my DROID BIONIC using Tapatalk

I don't have an explanation for it just the result comparison. I replaced the stock plugs and maybe they were gaped to wide after long use.

Why did your car do better with stock plugs?

[82DMC12]

I don't have an explanation for it just the result comparison. I replaced the stock plugs and maybe they were gaped to wide after long use.

Why did your car do better with stock plugs?

I don't know since I've never tried using +4's. I use standard Bosch Silver's. I prefer to let others experiment so I don't waste my money...

http://www.dmchelp.com/showthread.php?778-Bosch-platinum-4

Vendor comments are enough to make me stay away.

Andy

[stevedmc]

I don't know since I've never tried using +4's. I use standard Bosch Silver's. I prefer to let others experiment so I don't waste my money...

http://www.dmchelp.com/showthread.php?778-Bosch-platinum-4

Vendor comments are enough to make me stay away.

Andy

Dave is awesome.

[Ron]

And how can this be explained? I see no logical reason + 4's would help anything unless one of the tips break... You still have 3 left :-P

Sent from my DROID BIONIC using TapatalkOne of the ideas is that they will fire to the closest prong, and when it erodes enough, it will fire to the next closet, etc., multiplying the life (proper gap range) of the plug... -- There is not $.02 difference in the way it will run with the "correct" plug.

Avoid "close enough" crossovers and brands with high DOA and/or premature failure rates by using the Bosch Silver or Platinum.
If you want longer lasting snake oil, get the four prong ;-)

[stevedmc]

One of the ideas is that they will fire to the closest prong, and when it erodes enough, it will fire to the next closet, etc., multiplying the life (proper gap range) of the plug... -- There is not $.02 difference in the way it will run with the "correct" plug.

Avoid "close enough" crossovers and brands with high DOA and/or premature failure rates by using the Bosch Silver or Platinum.
If you want longer lasting snake oil, get the four prong ;-)

That is a good point about firing to the next closest when one prong wears out.

Here is a thought. I wonder if the 4 prong plugs have different gaps amongst each prong. I'm not poking fun but am genuinely curious.

[Ron]

That is a good point about firing to the next closest when one prong wears out.

Here is a thought. I wonder if the 4 prong plugs have different gaps amongst each prong. I'm not poking fun but am genuinely curious.Their goal is to make them the same...if they made them progressively shorter, then they would be wasting the difference for each of the three shorter ones... As is, they take turns being the longest (repeatedly), but not necessarily in order, of course...

[Bitsyncmaster]

It makes sense that the +4 would have four times the life. Maybe the fact the spark is open at the bottom is why it seemed to work better for me.

[stevedmc]

It makes sense that the +4 would have four times the life. Maybe the fact the spark is open at the bottom is why it seemed to work better for me.

True but isn't it amusing that a certain vendor replaces these plugs without question whenever working on ignition problems?

[sean]

True but isn't it amusing that a certain vendor replaces these plugs without question whenever working on ignition problems?

Amusing? I suppose I dont understand Steve humor. There were also times when certain vendors said we had to use Purflux oil filters(might be before your time) and that Nology spark plugs/wires added performance.

[dmc6960]

I had tried the +4 in combination with an alternate coil way back 8 years ago. Car ran like absolute crap the whole time they were in there. Put the stock coil back on with a new set of copper plugs and all was good again. Dont know if it was both, a combo of both, or just one of the two. Never looked back. That was the shortest lived waste of money I ever put in the DeLorean.

[Bitsyncmaster]

True but isn't it amusing that a certain vendor replaces these plugs without question whenever working on ignition problems?

I have two sets of the vendor recomended plugs just waiting for my +4 s to cause problems. It's been 5 years and they still run so good I have not replaced them.

[stevedmc]

Amusing? I suppose I dont understand Steve humor. There were also times when certain vendors said we had to use Purflux oil filters(might be before your time) and that Nology spark plugs/wires added performance.

I believe captain carburator and Grady believe in regular spark plugs as well.

[sean]

I believe captain carburator and Grady believe in regular spark plugs as well.

I'll congratulate them the next time I see them.

[Johny181]

The idea of the +4 connects are ridiculous in my view. The ignite will only journey across one of the prongs and not all four. I've never had a issue with effectively gapped connects. What I have had a issue with is connects that weren't gapped to the appropriate establishing.

[Ron]

The ignite will only journey across one of the prongs and not all four.
True...the spark will jump to the closest electrode. But it will erode and the spark will jump to the next longest, and so on... They just last longer.

[Bill Robertson's Sock Puppet #1]

It is extremely difficult to change multi electrode plug gaps, which does rule them out for certain custom ignition setups.

[David T]

If you compare the cost of the plugs and consider the mileage most of us put on our Deloreans it doesn't make economic sense to spend the extra coin on the more expensive plugs. There is no improvement in performance or gas mileage. Who needs a plug that can last 100,000 miles in a Delorean?
David Teitelbaum

[Kenny_Z]

After this:

http://uploads.m-cgi.com/kennyz/plug.jpg

I'll stick with traditional plugs in all my vehicles. I did have an issue with a head gasket leak in that cylinder but I've read that this is a common problem with this type of plug. You can see the traditional plug is just as dirty when I pulled the head but not cracked or broken after more miles.

http://uploads.m-cgi.com/kennyz/monte/engine09.jpg

[sdg3205]

If current trends continue it will be 2082 when i hit 100k miles.

[Ron]

fwiw, I wasn't suggesting to use the multi-prong plugs, just explaining the idea behind them...

Delorean or not, if the engine is stock, you are almost always better off to stick with the plug the manufacturer calls for. Why toss all of the manufacturer's re$earch out the window when they want performance just as much as we do? (Emission/mileage requirements wouldn't force the use of a different plug. Look at an old chart when they had a free hand -- sometimes the same plug was used from I4 thru V8.)
Same thing goes for any of the ignition components. Change one, and you change the characteristics of the burn. ...And even if you tweak things for a particular engine, if you get your fuel from a local gas pump, you wasted your time.

Bosch HR 6 DS
Word.