fundamental concept question

[threestar40]

I was talking with an old drag racer the other day and I have been working on a diesel sailboat a little lately. Something has been on my mind about the MASS of a fly wheel.

When I was taking the diesel out of the boat and looked at the sheer mass of the flywheel I thought to myself "No wonder diesels have so much torque. The flyheel is so heavy...once they get to turning they are hard to stop."

The old drag racer said in his day running a high compression 283 block bored and stroked to a 305 he ran a 60 pound flywheel with a powerglide because the motor was such a revver it ran out of breath and torque on the top end. I could kind of see his point not really, hence my question,

What are the advantages and disadvantages of running a heavier flywheel on a gasoline motor...esp. with a automatic tranny?

Rick =)

 

[Rob]

Hmmm....good question. I guess one disadvantage that I can think of is that with the increased weight, it takes more engine power to rotate that additional mass, therefore there is a greater degree of driveline loss.

I believe some ZR-1 owners that have replaced their dual mass flywheel setup with a single flywheel have experienced slightly greater acceleration because the engine doesn't have to work quite as hard as it did with the dual mass flywheel.

That's my understanding anyway. Maybe others can shed some better light?

 

[warren s]

Thats a new one on me, with an auto i cant see any differance.

Except- back in the 70s a popular conversion was to run an automatic with no torque converter, but an actual clutch setup.

This was a poor mans Lenco. So it was the same as having a heavy flywheel in an manual.

 

[4cefed]

Advantages = greater amount of potential energy for quicker launches.
Disadvantages = Slower acceleration.

Heavier = better for drag racing
Lighter = better for road racing

Thats my stab at it. What do ya'll think?

 

[threestar40]

4ce, that is exactly what rkreigh said over at the lt5registryforum, What about top end effects and if the heavy one is better for drag racing because it hits harder on the launch, does that make up for the loss in acceleration?

Thanks for the replies,

Rick =)