Damper diameter performance question

[cncguy987]

A smaller diameter damper is lighter etc, but is a larger diameter better for any reasons? Would the stroke of a crank dictate using a smaller or larger one?

[PackardV8]

A smaller diameter damper is lighter etc, but is a larger diameter better for any reasons? Would the stroke of a crank dictate using a smaller or larger one?

Define "better".

Yes, for ultimate dampening of torsional vibration, larger and heavier is better.

No, for faster acceleration of rotating mass, smaller is better.

Maybe, define your application.

[Lizardracing]

Also consider the weight ya going out there in the nose. 8” damper on a stock or cast steel 350 snout is a lot.
Scat says to use the 6” on there 9000 series stuff. I’ve had a failure Before when the key tore out the damper slot but no damage to the crank snout.

[PackardV8]

Also consider the weight ya going out there in the nose. 8” damper on a stock or cast steel 350 snout is a lot.
Scat says to use the 6” on there 9000 series stuff. I’ve had a failure Before when the key tore out the damper slot but no damage to the crank snout.

For true. The SBC crankshafts made with a BBC snout are for a reason. Back when, the Ford FE truck 361"/391" crankshafts are the same as the car until the huge diameter, long snout because of the extended high RPM with AC and air compressor loading.

[cncguy987]

To go further into my question, i was curious if a larger diameter damper would dampen the harmonics of the engine the same or better and does the cubic inches of the engine effect that. Would cubic inches mandate a larger one? The engine is a top of the line dirt late mod engine, 430 ci, with a bbc snout.

[MadBill]

Years back on S-T, I referenced SBC tests by David Vizard. AIR, even with 600 RPM/sec. pulls, the biggest (8") damper made the most power and the bare hub made the least.
Here's some info and further links: http://www.atiracing.com/products/dampe ... /index.htm

[BOOT]

Use, power level and displacement are factors. Just ask a aftermarket manufacture and give them your info. For example a trailer queen track drag car, just a hub is said to be sometimes used. Trucks or performance(not the weak 70's low hp) sbc would have the larger diameter unit but an aftermarket might do better n not need to be as large. Another factor would be the number of belts and accessories. Usually safe to go larger with a damper if your want to protect your investment.

FYI some aftermarket type need to be rebuilt/replaced if you have a major engine failure

[rebelyell]

There's a LOT more to this than big or little; ask the pros at BHJ
https://harmonicdampers.com/index.php?m ... il6nmqemj7

http://harmonicdampers.com/downloads/pd ... r_Info.pdf