Roush vs 427FE vs Keith Craft

[AL427SBF]

Originally Posted by Cobra #3170

That is the rate that those engines gain revolutions when free reved. The point is they can reach maximum rpm in about .16 seconds from idle speed in the case of the 500 inch hemi fuel engine and about .28 seconds in the case of a rather small 183 cid F1 engine. They free rev at the same rate to maximum rpm which is truly phenomenal especially when you hear either one.
It just shows that there is a lot more to it than component mass.

Fair enough, I see your point so my post edited accordingly

But I think you'll agree it's still apples and oranges to the point of this hijacked discussion - the engine architectures are nowhere near the same.

The premise on this sidebar has been - generally, when you have a SB and BB making near same power, the parasitic drain from the rotating assembly and reciprocating mass on a BB has a greater impact on acceleration vs SB.

Granted, when you're making 8000 HP on a nitro fed hemi, the rotating & reciprocal parasitic loss difference to a race fueled 800 HP cosworth is obviously overcome by the shear power of the hemi.

Btw, if you do the math with those motors, the cosworth with max RPM at 18000 and hemi at 9500, then the cosworth gets to 9500 RPM .01 faster than that godzilla hemi and David beats Goliath once again - but by the slimmest of margins lol. (just funn'in with ya)