We like flat plane crank V8s because they are optimized for a high redline, and they are only found in halo cars, supercars, and the top end of professional motorsports. Due to the use cases, they are also reasonably light for their power.
We like flat plane crank V8s because they are optimized for a high redline, and they are only found in halo cars, supercars, and the top end of professional motorsports. Due to the use cases, they are also reasonably light for their power.
I don't know about being optimized for a high redline. The larger the engine, the more they DON'T like high revs because of the secondary shaking. As noted upthread, the almighty Cosworth DFV had its redline dropped substantially for reliability reasons when used in endurance racing, and Porsche went to a cross plane crank for their flat eights for vibration reasons.
The highest revving large (greater than 5 liter) V8 engines in racing are all cross plane. If NASCAR and Top Fuel and Pro Stock felt there was an advantage with a flat plane crank, they would be using that. And they did try it at least once. Note that in PS they have a lot of leeway with engine design and they will do things like have two different bores and two different strokes because the end cylinders have a different induction path than the middle four, and they adjust intake tract length by changing the deck height. Apparently there are 500ci PS engines with deck heights in the 8" range!
What is interesting is that an engine builder did a test on a Winston Cup engine, I'm thinking it was from the era where they were kissing 10k, where for S&Gs he made "headers" from 8 inch stubs dumping at a right angle into a 4" log... and power did not change.
Pete. (l33t FS) said:The highest revving large (greater than 5 liter) V8 engines in racing are all cross plane. If NASCAR and Top Fuel and Pro Stock felt there was an advantage with a flat plane crank, they would be using that.
One needs to be careful with this logic, otherwise it would imply that there was no benefit to fuel injection before 2012...
Back to the original question, what about that Buick V8 that they sold to Rover? Weren't there flat plane crank versions of that?
In reply to codrus (Forum Supporter) :
Arguably the only benefit to EFI is drivability 
People have not been able to make as much power with port EFI as with a carburetor. Something about the superior atomization, the additional mass in the airstream affecting ram tuning, not sure.
It is interesting to note that F1 injected the fuel UP into the plenum, not down into the ports, and they were running at extremely high pressures to get the kind of atomization you can get with some calibrated orifices and an emulsion well
If I go forth with my 4.8 plan - and this thread is making be realize why I probably still would not be happy with it - it will be carbureted. Note that a decent carb costs as much as an EFI controller, plus it would still need a $700 MSD unit to control spark, so this is not for economical reasons. They just respond better when you have a good carb.
In reply to codrus (Forum Supporter) :
I've heard that flat plane crankshaft were offered for the Rover/Buick engine but I don't think that was a factory configuration.
Came stock in the TVR Cebera. But it wasn't really a buick/rover engine anymore. It's under 100hp/liter, not really worth it.
In reply to mr2peak :
Wow. Neato!
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