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I'm wondering what the maximum bore and stroke of a couple of engines, and possibly their approx. max capacity (though I can figure that out though an online engine capacity calculator).
I'm namely wondering about the PRV V6 and the Cosworth DFV. Would anyone have any idea what the maximum practical bore and stroke measurements for these engines would be?
As far as the DFV is concerned, the maximum size was about 3.9 liters (within the given external dimensions of the engine). I do not know what the corresponding bore and stroke was, but I guess it combines the 90 mm bore of the DFY, with the original 65 stroke of the DFV. Your engine size calculator will do the math.
That actually gives the approx. displacement of the 3.3 liter version that was popular in Group C Junior/C2 racing.
If the DFL used the 90mm bore of the DFY, then the stroke would be about 77mm or so. That gets you to around 3.9 liters.
The reason why I also asked about the PRV is that the max displacement produced was 3.0 liters (2975cc to be exact--93x73mm bore/stroke). But I also read that at Le Mans in 1996 that the Renault Sport Spider derived Helem GT1 cars used a 3040cc version. So I'm wondering what the bore and stroke would max out to, as well as to see what the original V8 version's max displacement would be.
[quote=Chernaudi;1012420]That actually gives the approx. displacement of the 3.3 liter version that was popular in Group C Junior/C2 racing.
If the DFL used the 90mm bore of the DFY, then the stroke would be about 77mm or so. That gets you to around 3.9 liters.
The reason why I also asked about the PRV is that the max displacement produced was 3.0 liters (2975cc to be exact--93x73mm bore/stroke). But I also read that at Le Mans in 1996 that the Renault Sport Spider derived Helem GT1 cars used a 3040cc version. So I'm wondering what the bore and stroke would max out to, as well as to see what the original V8 version's max displacement would be.[/quote]
yes 3.9 was the maximum I found too, but apparently that engine vibrated the whole car to pieces. It was replaced by the 3.3 version. I do not know how the Douvrin engine arrived at over three liters.
Also, it should be known that engines like the Zytek and Mugen LMP1 V8s were in ways distant relatives of the DFV family, but they were able to go up to about 4.5 liters.
And when I say distant relatives, that's what I mean--those engines are probably hugely different in reality than the DFV, even if the DFV inspired elements of their designs.
And back to the PRV and the original plans for the engine to be a V8, I wonder what Peugeot, Renault and Volvo were trying to get that engine to compete against? I'd have to say things like the Buick/Rover V8 and the smaller displacement (3.6 or 4.3) liter Ford Windsor small block V8, though the Windsor was never a very common engine in Europe for production cars.
Rover V8, the smaller Merc V8s, also probably for some more cachet in America.
There were many projects back in the mid/late sixties and early seventies to develop large V8 engines/rotary engines for luxury/executive cars which were cancelled when the 1973 Oil Crisis started. For instance BMW designed a V8 for their 7 Series back then, but with the advent of the crisis the focused on developing the existing straight six engines.
The PRV ZSN4 V6 first turned up at Le Mans in 2.7 litre normally aspirated form aboard the privateer WM in 1976.
Over the years the small band of WM enthusiasts added 4 valve heads, turbos and sundry extras of their own design and manufacture.
Peugeot 'assisted' unofficialy, building a version of the ZSN4 capable of being used as a stressed member, also taking the bore out to 91mm, for a capacity of 2850cc and 540BHP at race boost.
By 1988 the Dennis Mathiot Competition developed version of the V6 was eased out to a 93mm bore and near 3000cc with a claimed output of 950BHP.
WM ran their final race in 1989, which more or less ended the career of the PRV ZSN4.
Thanks Wombat, that gives some good insight.