What is the Best PRV engine combination ?

[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:

BlueBus1.jpg

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.