Lwt Flywheel & Lwt Crank Pulley ?'s

[tonjohn]

My friend told me that getting a lightweight Crank pulley yields a similar affect as getting a lightweight flywheel, but at a substantial cost difference.
He also said that it is supposedly bad to have BOTH the lightweight crank pulley AND lightweight flywheel due to harmonic vibration issues. Is this true?

If that is true, which upgrade is the best way to go?

Anyone installed a lightweight Crank pulley yet?


The crank pulley i am talking about is from MiniMania

[scpaul]

I saw MiniMania selling both of them, any one tried them out?

[olddad]

Don't do it. Lightweight crank pulleys serve the primary function of trashing your engine and belt driven equipment. The stock pulley has a rubber insulator between the hub and pulley, and this damping is necessary for smoothing out normal rpm variations. An engine revolution is a series of accelerations and deccelerations, and without damping the belts are jerked around. The harmonic vibrations of the engine will need that damping especially with a light weight flywheel. If a fluid damper becomes available it might be a good way to go, but the solid pulleys spell death to a 4 banger.