Lightened Flywheel

[BRENT in 10-uh-C]

Originally Posted by Dave in MN

We even tried Ron Kelly's method of modifying a SB Chevy front harmonic balancer and mount it to the inside of a lightened flywheel. It actually worked the best in narrowing the vibration range. Voodoo or fuzzy logic I know but it was hard to argue with good results.
Good Day!

I'm pretty confident that all Mr. Kelley's balancer did was add weight to the center of the flywheel. The flywheel mass (-of any weight) cancels any affect of the flywheel mounted balancer when they are both mounted onto the same flange. If it were mounted onto the opposite end of the crankshaft where it could dampen the torsional pulsations of the crank, then it would do a lot of good.

[wensum]

Originally Posted by BRENT in 10-uh-C

I'm pretty confident that all Mr. Kelley's balancer did was add weight to the center of the flywheel. The flywheel mass (-of any weight) cancels any affect of the flywheel mounted balancer when they are both mounted onto the same flange. If it were mounted onto the opposite end of the crankshaft where it could dampen the torsional pulsations of the crank, then it would do a lot of good.

Thanks for that observation Brent, It was my understanding that a harmonic dampener is most effective at the front end of the crankshaft? Having seen a a flywheel mounted dampener, not only did it look complicated, but one also has to remove the motor to fit it. Whereas the Harmonic dampener pulley is so much easier to fit, and in my experience, very effective.

[Synchro909]

While I'm no expert in this area, it seems to me that a heavy flywheel will cause greater torsional stresses in the crankshaft due to its inertia. For that reason, I have gone with a lightened one at the back and one of those Murray Horne (From NZ) harmonic balancers on the front. I have no reason to regret that.

[Dave in MN]

Originally Posted by BRENT in 10-uh-C

I'm pretty confident that all Mr. Kelley's balancer did was add weight to the center of the flywheel. The flywheel mass (-of any weight) cancels any affect of the flywheel mounted balancer when they are both mounted onto the same flange. If it were mounted onto the opposite end of the crankshaft where it could dampen the torsional pulsations of the crank, then it would do a lot of good.

Brent,
I agree, it added weight and that was key in lowering the range of vibration. The same happend when a flywheel of approximate equal weight, that was solid...no balancer added, was tried.
The difference between the two was the range of vibration was much tighter and less in intensity to almost not noticeable. The mounted balancer appears to take the edge off the torsional pulse, when a cylinder fires or the maximum pressure is reached on the compression stroke. I now run that version of flywheel in my Phaeton.

I tested these varying flywheels with the engine on the dyno. By varying the load at the rpm the vibration was most evident, the vibration could be intensified and clearly observed. The battery of tests taught me how to better build and tune an engine. Again...some say fuzzy logic but the dyno and results don't lie.

I have tried one of Murray Horne's combination front pulley/dampers. It also helps lessen the observed harmonic slightly. I need to complete more tests on his product when I have time. Available time seems in short supply of late.
Hope you and family are doing well...Good Day!