What is the Best PRV engine combination ?

[MartyP]

I would like to know to know which combination of engine parts in stock form would givve the more power and still be reliable.

I just heard so many different things ???

Anything from a:
3.0L eagle Premier
B28E or F
B280 from a volvo
B27 ?

Base, cranckshaft ?
cylinder
head
piston
cams
injection type ?

etc...

[Andrew]

The Renault Alpine A310 Pack GT used a modified 2.9 PRV with triple two barrel weweb carbs. The result was 193 HP.

Also the Talbot Tagora SX used a 2.6 PRV with dual three barrel weber carbs and produced 166 HP.

From what I recall , there were only 27 Apline Pack GT's ever built. While there were approximately 1,000 Tagora Sx's built, finding one in 2015 would be quite a challenge.

[opethmike]

Any gains you would get from this sort of thing would be small, and worth neither the effort, nor the money.

[DMCVegas]

Any gains you would get from this sort of thing would be small, and worth neither the effort, nor the money.

Painful as it sounds, that is the absolute truth. As it was told to me many years prior when I started inquiring about the same thing, the answer I got was that if there was a cheap and easy way to extract more power with a combination of parts from other PRV engines, we'd all have those bits installed already.

While the PRV is indeed a modular engine, many of the key modular parts vary greatly from iteration to iteration. Example: When you're looking at those higher power numbers for Carbureted and Electronically Injected engines, a sizable part of that is due to their cylinder heads with larger intake ports because of the absence or relocation of the fuel injector bosses. And the list goes on with other parts.

Mechanically speaking the easiest thing would be an Alpine A310 top end with a performance manifold, cams, and carb. But that is NOT cheap nor easy to track down all the cores you'd need to exchange not just for those parts, but for the other ones to adapt them to your engine.

Your best bet is either DMCH or DPI if you want increased PRV performance.

[opethmike]

I suppose we should ask OP what the goal for the engine is?

[MartyP]

Reliability and a little more performance.

Without spending 10K on complete new system.

Just parts that you can swap that would make it the best prv.

[Delorean Industries]

Just drop in a 3.0 with a set of headers/efi and call it a day. Best you can get without spending on advanced development components within that price range.

[SEO Motorsports]

3.0L eagle motor with Euro B280E camshafts, EFI, head studs and a good centrifugal supercharger, headers, 8psi and call it a day.

The absolute best PRV setup would be take the block and send it to Golden Eagle or Benson to have it sleeved with ductile iron sleeves. You could go over bore and make a 3.2L if you wanted I'm sure. This was my plan before I went with the 2JZ engine in my car.

https://www.goldeneaglemfg.com/index.php?main_page=page&id=1
http://www.bensonsmachine.com/benson-sleeves.html

Crower should still have the specs on the rods I had made years ago and CP made my 3.0L pistons. This was way back in 2005 but I'm sure they keep records, just give them a call. I would have the heads ported with the focus around the bowls/valves and open up the exhaust ports to match the gasket. B280E or custom cams and always add boost to a PRV, they will always be dogs without it. I would love to build one of these,with someone else money of course!!

[MartyP]

The plan is only to have the best engine I could get

I know there are some difference beween the engine in the Delorean, The Volvos 760,262,264 and even the Peugeot 505 PRV.

I was looking at the best compnent that would it between each other.

B28
B280E
B280F

[Farrar]

The B280 engine had provision for an oil cooler, and main bearings #2 and #3 were cross-bolted. But unless you plan to go forced induction, the Eagle/Dodge 3.0L swap will probably suit you just fine.

[nullset]

Just drop in a 3.0 with a set of headers/efi and call it a day. Best you can get without spending on advanced development components within that price range.

Josh,

I'm curious - starting with a stock 3.0, what all is needed to do the conversion? Do you offer a kit of parts or have some suggestions?

[JohnLane]

I have stroked the even-firing crank from 73 to 79.2
Three liter sleeves can be oversized to 93.5 and use a standard head gasket.
Pistons are custom anyway so do the math for how to shape the piston crown. I give them a dish with a nice radius for effectively a quench pad all the way around the combustion chamber.
All else being equal more displacement makes more torque.... Torque being what presses you back in the seat.
Forced induction makes for much more torque.
I prefer the B-280 block for the cross-bolted mains and oil cooler.
Cylinder heads are where the D got robbed for power. Bummer that a nice four cam four valve head never got produced that we could use.
I'd love to give an even firing head direct injection. Use the quench pad for the spot to put the injector.
Current programmable engine management is the cat's pajamas. Makes lots of power whilst keeping the engine from blowing up.

[jamesrguk]

I dumped in the full Volvo b28e engine into my car last year, due to my own one suffering block rot.

It's a much nicer drive and I look forward to popping it on a dyno in the future but preferably along side other d's to enable direct comparison, as indeed we did at eurotec a few years back.

I have had most of the configurations in my ownership including:

1) stock oem engine b28f
2) oem with cat bypass
3) oem with bypass and Volvo b28e fueling
4) oem with free flow exhaust and Volvo fueling (dyno'd at eurotec and won 'fastest auto' I have a t-shirt to prove it!)
5) full Volvo b28e

Better torque from the b28e does make for the best 'original looking' set up IMHO but I would like to dyno it at some point.

If you can get a Volvo b28e grab it and keep everything, after all aside from the sandwich plate and sump it's all interchangeable.

Obviously you may come up against emissions issues in the states.

I

[Farrar]

All else being equal more displacement makes more torque.... Torque being what presses you back in the seat.
Forced induction makes for much more torque.

Finally someone who knows that a million horsepower doesn't mean jack without torque to back it up. What a breath of fresh air!

Welcome to DMCTalk, John Lane! Thanks for all of the useful info you've posted on the TurboBricks forum over the years. I took some notes and have a parts list going for my "dream PRV build." :)

[content22207_2]

Finally someone who knows that a million horsepower doesn't mean jack without torque to back it up. What a breath of fresh air!

Horsepower doesn't exist -- ie: there is no independent "horsepower" measurement (there is no such thing as a "horsepower gauge").

Horsepower is a mathematical calculation based on other independent measurements that do exist: torque and RPM (there are a multitude of gauges to measure torque and RPM).

Formula is: Torque x RPM / 5252.

(For the morbidly curious there is a historical basis for this formula, based on how much water James Watt assumed a "typical" horse could raise from a coal mine).

High horsepower numbers depend upon high torque or high RPM (or both, though they tend to be mutually exclusive -- it's hard to get high torque engines spinning very fast, and engines that spin very fast tend to produce less torque).

Popular misconception is "horsepower" translates into a team of horses harnessed to the front of your car like a Conestoga wagon -- 200 horsepower is equal to a team of 200 real life horses dragging your car around. Obvious problem is: what kind of horses are they? A team of 200 Shetland ponies is not equivalent to a team of 200 Clydesdales, but they are both "200 horsepower".

A low torque engine with high horsepower rating has to spin very quickly to produce those numbers. Think of a motorcycle engine. But until that engine is spinning quickly it produces very little power. That is why you don't see small cars pulling heavy trailers -- they can't even get they load moving without stalling or burning up the clutch/transmission (every once & awhile somebody gets the bright idea to pull a U Haul cross country with their Honda, usually blowing something up in the process).

A high torque engine with low horsepower rating does not need to spin quickly to produce power. That is how a semi tractor with "only" 300-400 horsepower can move a 60,000 lbs trailer (multiple gear ratios help obviously -- typical semi tractor only revs to ~1,500 RPM before shifting).

I have a Lincoln with a 7.5 liter engine that produces "only" ~250 HP. Yet it manages to propel the car's 5,000 lbs girth 0-60 MPH *FASTER* than a DeLorean (right at 8 seconds). How is that possible? Do the math: the engine produces 500 lbs of torque at 2,800 RPM -- it's a high torque low rev'ing engine. The engine does not need to be spinning quickly to produce power -- it has significant power even at idle. That same engine was used in tow trucks, Coca-Cola trucks, fire trucks, etc for many years for that very reason. You can not say the same for small displacement engines that have even higher horsepower ratings.

Similarly my 26,000 lbs GVWR (18,000 lbs light weight) school bus has a 6.9 liter gasoline engine, producing ~220 HP. It's nowhere as fast as my Lincoln of course, but it does propel itself just fine -- Thomas wouldn't have put a bus body on it otherwise. How is that possible? My bus weighs 5-6 times more than a typical passenger car, and carries 6-7 times as many people, but its engine is rated at *LESS* horsepower than most automobiles. Answer is the same: it has a low rev'ing high torque engine that yields a low horsepower calculation but significant power from idle to its much lower red line.

Horsepower numbers are all fine and good, but unless you understand what they really represent you're just salivating to marketing and advertising slogans like one of Pavlov's dogs.

Bill Robertson
#5939

[content22207_2]

As stated, my school bus has a 429 (6.9 liter) gas engine:

44261

Of course a diesel would be more powerful, but this gasoline engine propels the vehicle just fine (gasoline powered school buses were extremely common until the end of the 1980's -- some with engines as small as 305 cubic inches). Transmission is a 4 speed automatic.

Even though the 429 is a Mustang engine, the light weight (empty) of my bus is nearly 6 times heavier than a Mustang, and fully loaded it carries 42 people (more than 8 times as many as a Mustang). The secret ingredient is torque, albeit lower BTU gasoline torque versus higher BTU diesel torque.

High rev'ing small displacement engines have their place and purpose, but as the old saying goes, "there's no replacement for displacement".

Bill Robertson
#5939

[Farrar]

as the old saying goes, "there's no replacement for displacement".

I guess it's a good thing #2613's next engine is a 3.0L, then... (Fingers crossed!) :)

[content22207_2]

You're talking about 9 cubic inch increase -- less than a push lawn mower. I wouldn't hold your breath.

There are plenty of 3.0 advantages over its 2.85 predecessor, but displacement really isn't one of them.

Bill Robertson
#5939

[JohnLane]

The even-firing engines will have that perfectly smooth idle.

More displacement makes a higher static compression ratio. Can bump it to almost 3.4 liters.

With the 'E' heads of the three liter the intake ports are hugely improved over the odd-firing heads.

This requires the even-firing intake. I have run them on K-Jet and machined the hole in the head to run the distributor. B-280f cam is short in that bank to run the balance shaft offered in other markets. A distributor drive gear can be bolted to it... Ran nice. Current engine management does wonders. 60-2 trigger on the crank + #1 trigger on a camshaft. Real sequential injection. Win.

Even-firing 3.4 liter with odd-firing heads and free flowing exhaust will be indistinguishable from standard with wayyyy more torque.

[Nicholas R]

Horsepower doesn't exist -- ie: there is no independent "horsepower" measurement (there is no such thing as a "horsepower gauge").

Horsepower is a mathematical calculation based on other independent measurements that do exist: torque and RPM (there are a multitude of gauges to measure torque and RPM).

Formula is: Torque x RPM / 5252.

(For the morbidly curious there is a historical basis for this formula, based on how much water James Watt assumed a "typical" horse could raise from a coal mine).

High horsepower numbers depend upon high torque or high RPM (or both, though they tend to be mutually exclusive -- it's hard to get high torque engines spinning very fast, and engines that spin very fast tend to produce less torque).



For what it's worth, Torque is also a mathematical calculation: Force X Distance. You just don't notice because your torque wrench is already calibrated to determine the force at the distance between the head and the midpoint of the handle.

Also, there most certainly is a "horsepower gauge," it's called a dynamometer, and in the engineering world, power/horsepower/watts are regularly used independently. And sure, you can make the argument that some dynamometers measure torque and RPM and do a calculation, but if so, you can also make the argument that a torque wrench just measures force and distance and does a calculation. That said, there are a lot of different ways to determine and calculate power without the need for torque. A lot of dynomometers actually determine the amount and rate of work (work as in the measure of a force through over a distance) being performed, and later back calculate the torque in order to also have that measure. In the end, horsepower is a measure of how much energy a device can output over a period of time. Any device that measures power or energy over time is a "horsepower gauge".

Sure when you're talking about engines, horsepower is a bit more difficult to perceive than torque (which you can compare to a wrench on lug nuts), but its measure certainly has it's use, just as torque does.

[content22207_2]

You all have me convinced -- while I've got my 18,000 lbs school bus at the house over the weekend I am going to snatch out its cast iron V8 with a mere 220 HP and replace it with a lightweight aluminum motorcycle engine pumping out more than 250 HP. Surely those additional 30 horses will make the bus faster than it's ever been before -- numbers don't lie....

(And just look at all the extra space I will get under the hood. I could even mount the bus' new engine between my feet in the passenger compartment. This is going to revolutionize commercial transportation).

Bill Robertson
#5939

[Drive Stainless]

For what it's worth, Torque is also a mathematical calculation: Force X Distance. You just don't notice because your torque wrench is already calibrated to determine the force at the distance between the head and the midpoint of the handle.

Also, there most certainly is a "horsepower gauge," it's called a dynamometer, and in the engineering world, power/horsepower/watts are regularly used independently. And sure, you can make the argument that some dynamometers measure torque and RPM and do a calculation, but if so, you can also make the argument that a torque wrench just measures force and distance and does a calculation. That said, there are a lot of different ways to determine and calculate power without the need for torque. A lot of dynomometers actually determine the amount and rate of work (work as in the measure of a force through over a distance) being performed, and later back calculate the torque in order to also have that measure. In the end, horsepower is a measure of how much energy a device can output over a period of time. Any device that measures power or energy over time is a "horsepower gauge".

Sure when you're talking about engines, horsepower is a bit more difficult to perceive than torque (which you can compare to a wrench on lug nuts), but its measure certainly has it's use, just as torque does.

Nick,
I know that Bill started off with "Horsepower doesn't exist," but his other point was that the figure seems useless in comparing engines (250HP school bus vs. 250HP motorcycle). As a ME, could you comment on where is the horsepower measurement is most relevant?

[content22207_2]

(250HP school bus vs. 250HP motorcycle)

220 HP school bus.

By the numbers, a motorcycle is 14% more powerful than Ford's V8.

Bill Robertson
#5939

[content22207_2]

Of course my bus' front wheels alone (just the tires and rims) weigh about the same as a motorcycle, so I'm a little befuddled how a numerically superior motorcycle engine is going to manage to drag the rest of the vehicle around, but numbers don't lie....

Bill Robertson
#5939

[Nicholas R]

Nick,
I know that Bill started off with "Horsepower doesn't exist," but his other point was that the figure seems useless in comparing engines (250HP school bus vs. 250HP motorcycle). As a ME, could you comment on where is the horsepower measurement is most relevant?

Horsepower is always a measure of the rate at which the engine/motor/power system is able to produce/convert energy. For me, horsepower is very important because it never changes, despite gearing. If I spec out a 10hp electric motor, no matter how many reducers, gearboxes, pulleys, etc. I add, the system will still always be delivering 10hp. Most gearboxes and such are therefore rated by HP. Torque on the other hand changes at every step. A 30:1 gearbox multiplies the torque by 30 times, where a 1:30 gearbox divides the torque 30 times.

We say "100hp/100ftlbs at the rear wheels" but obviously thats not actually true. The torque at the wheels is a factor of the ratio of the gear you're in, and the differential/final drive ratio. With the DeLorean's 3.44:1 differential, even in 4th gear where the ratio is almost 1:1, the actual wheel torque would be 344ftlbs.

Now by no means am I saying that one measurement is more important than the other; both have value and both are important when considering an engines capability. You cannot compare the capability of a motorcycle vs a schoolbus based on one number because both have their merits. A school bus can haul far more, but obviously a motorcycle can accelerate far faster. Which do you want?

There really comes a lot of difficulty in comparing engines as though they're all like for like. A steam engine may produce 10,000ftlbs, but only at 10hp, since it's turning so slowly. Sure it can deliver a ton of torque, but the actual rate that it does that is arduously slow (Maybe 10-30RPM). To compensate, it will likely add a gearbox to increase the RPM but decrease the torque. On the other hand, a Formula 1 engine may make 1000hp, but only 250ftlbs. Torque is low, but the rate of delivery is ridiculously high (up to 20,000RPM). Similarly, a gearbox will reduce the RPM and increase the torque.

Personally, I wouldn't want either of those in my DeLorean, just like I wouldn't want a motorcycle or a school bus engine. I need and engine that is designed to produce power at a rate and RPM range that is consistent with the gearing of the car, with a torque rating that is appropriate for the amount of mass I'm trying to move. Though in my case that's not a PRV, it's a modified LS1 :wink: :burnout:

[Farrar]

I think the problem (and BOY are we off topic now, oops!) is that marketing pushes horsepower. It has "power" in it so otherwise uninformed consumers will go "ooh, more power" and buy the car with the bigger number. Personally, I think a power-to-weight ratio would be more useful, but tell that to marketing.

Long story short: marketing ruins everything. LOL ;)

[Delorean Industries]

Well said nick. Rate of delivery.

[content22207_2]

A dollar is a dollar. Doesn't matter whether it's 100 pennies or a single dollar bill -- both have the same purchasing power.

Ipso facto, horsepower is horsepower. Doesn't matter if its a big cast iron V8 or a little aluminum 4 cylinder: 250 HP *MUST* be more powerful than 220 HP -- 30 horses more powerful to be precise. Numbers don't lie....

Bus is in service this week, but perhaps over the weekend I can bolt up a little motorcycle engine.

Wonder if I should snatch out the 60 gallon gas tank and install a 4 gallon motorcycle gas tank while I'm at it?

World's first 1.5 liter school bus with 4 gallon gas tank -- I am going to be the envy of every school system in the country.

Bill Robertson
#5939

[content22207_2]

I am negotiating buying my church's bus as a backup. That thing has a diesel engine that is bigger than my gas burner but only puts out 170 HP -- what a dog.

Bill Robertson
#5939

[davidc89]

I am negotiating buying my church's bus as a backup. That thing has a diesel engine that is bigger than my gas burner but only puts out 170 HP -- what a dog.

Well the Diesel doesn't have a carburetor so....

[Nicholas R]

I am negotiating buying my church's bus as a backup. That thing has a diesel engine that is bigger than my gas burner but only puts out 170 HP -- what a dog.

Bill Robertson
#5939

Why stop there? Why not go with one of those steam engines. Sure they may make only a dozen or so HP, but who cares because they make huge amounts of torque, which is all that matters right? :wink:

[content22207_2]

I don't want torque, I want horsepower -- the more the better.

A 250 HP engine is numerically more powerful than a 220 Hp or 170 HP engine -- the numbers prove it.

Why wouldn't I use the engine with the highest horsepower rating? It's just like a penthouse apartment -- apartment on the 100th floor will have better views than an apartment on the 75th or 50th floor.

Unless motorcycle manufacturers are lying, their little aluminum engines produce more horsepower than Ford's hulking cast iron monsters.

And horsepower obviously equals performance -- the more the better.

That's why everybody else chases after the highest HP numbers advertised. I'm just late to the party.

Bill Robertson
#5939

[Bitsyncmaster]

A dollar is a dollar. Doesn't matter whether it's 100 pennies or a single dollar bill -- both have the same purchasing power.

Ipso facto, horsepower is horsepower. Doesn't matter if its a big cast iron V8 or a little aluminum 4 cylinder: 250 HP *MUST* be more powerful than 220 HP -- 30 horses more powerful to be precise. Numbers don't lie....

Bus is in service this week, but perhaps over the weekend I can bolt up a little motorcycle engine.

Wonder if I should snatch out the 60 gallon gas tank and install a 4 gallon motorcycle gas tank while I'm at it?

World's first 1.5 liter school bus with 4 gallon gas tank -- I am going to be the envy of every school system in the country.

Bill Robertson
#5939

So you think the 200 mile range with 4 gallons of that motorcycle will be the same in the buss?

[content22207_2]

You do realize I am joking? As Farrar first pointed out, horsepower is not an objective number, comparable vehicle to vehicle, even though the general public assumes it is and treats it that way.

Numbers do lie: a 170 HP diesel is much more powerful than a 220 HP gasoline engine even when they are the same displacement (both buses are 6.9 liter -- vastly different blocks of course).

Horsepower is not horsepower -- certainly not comparing one engine to another.

Bill Robertson
#5939

[Nicholas R]

You do realize I am joking? As Farrar first pointed out, horsepower is not an objective number, comparable vehicle to vehicle, even though the general public assumes it is and treats it that way.

Numbers do lie: a 170 HP diesel is much more powerful than a 220 HP gasoline engine even when they are the same displacement (both buses are 6.9 liter -- vastly different blocks of course).

Horsepower is not horsepower -- certainly not comparing one engine to another.

Bill Robertson
#5939

I'd be careful with your wording. To say a 170hp diesel is more powerful than a 220HP gasoline engine truly is incorrect, simply based on how you've worded it. At it's base, horsepower is a measure of power just like kilowatts. If the power rating of one device is higher than another, it truly is more powerful.

If you say it can produce more torque, then you would be correct (though you haven't actually posted the amount of torque each produces so one cannot yet be sure.

[Farrar]

Perhaps it's time for a shift in the conversation. How do we define "best PRV?"

For me, "best" would be:
- powerful enough to accelerate the car safely (i.e. to accelerate onto an interstate highway using a short entrance ramp/lane),
- easy to maintain, and
- reliable.

Fortunately, the PRV is a sturdy little engine in almost every incarnation. The only flaw I've found is the tendency for block rot.

[Delorean Industries]

Best prv is easy. Dpi spec 2 legend twin turbo. Current consumer format is rated at 465 torque 318 hp at 15psi. Perfect balance between raw power and not testing the rest of the chassis apart.

4454144542

[sdg3205]

Best prv is easy. Dpi spec 2 legend twin turbo. Current consumer format is rated at 465 torque 318 hp at 15psi. Perfect balance between raw power and not testing the rest of the chassis apart.

4454144542

Jesus Murphy. So much want.

[OverlandMan]

Best prv is easy. Dpi spec 2 legend twin turbo. Current consumer format is rated at 465 torque 318 hp at 15psi. Perfect balance between raw power and not testing the rest of the chassis apart.

4454144542

Is that your car Josh? My PRV pants just got excited.

[Delorean Industries]

No Joshua Schwartz's car. Its currently coming back for intercooler system updates and a stainless chassis. I'll let Darren Decker post pictures of 5000 when he receives it of the current spec and updated appearance items. The one pictured is a gen II from above and gen I from below. The system now has a merged X pipe with dual converters standard.