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Old 05-04-2014, 06:32 AM
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Quote:
Originally Posted by xb-60 View Post
Don't we need to define 'rev'?
If you're revving the engine with no load, then OK an engine with lower rotational mass will rev quicker (all other variables being equal), but when loaded (accelerating on the road), a higher rotating mass won't make a measureable difference.
Cheers,
Glen
Yeah, we should have defined "rev" a good bit ago. I'm pretty sure what we're talking about is an engine's ability to accelerate though. There's a lot that goes into that, and as Ed mentioned, the flywheel weights along with the trans, and the rest of the car can affect the engine's ability in the car.

On the dyno, it's a different story though, and it's easy to hear how well an engine accelerates as it's going through its powerband.

You have to also remember that angular acceleration is caused by something. It's caused by torque, or a force applied at a distance.

Rotating assemblies have their own rotational inertia that has to be overcome, but horsepower and torque will easily overcome that and will accelerate the assembly.

FE's are certainly dinosaurs in the fact that they stem back to the late 50's/early 60's, but that doesn't mean that they are all antiquated. You can hamstring them with 40 lb flywheels, numerically low rearend gears, short camshaft duration, low compression, poor intake flow, etc......just like you can a small block.

But....

Just because the rotating assembly is heavier doesn't mean that it won't accelerate quickly or won't seem zippy, and in a lot of cases, I wouldn't even count on the rotating assembly being heavier.
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