i think i know why ka motors dont like high rpms

[InsanityInc]

I think for the normally aspirated KA a harmonic damper is not as important as a harmonic damper on say a F20C (S2000 motor).

The two factors which affect crank harmonics are:1) The power level: imagine the crank like a tuning fork which, everytime the combustion ignites, generates a frequency that travels through the reciprocating assembly. The bigger the bang (more HP), the more damaging harmonics. This has shown to prematurely wear bearings, cause crankshaft failures and bent rods etc...These symptoms are more apparent on Honda engines making lots of power that use solid hubs.

Sort of right, but for the wrong reasons. More HP != bigger bang. More Torque = bigger bang. 150tq@8600 ~= 240hp, 150tq@5600 is less horsepower, but the same amount of combustion energy (bang) per cycle. Higher RPM levels in and of themselves create more damaging harmonics. But like I said, it makes more sense to worry about more immediate problems before harmonics.

[NateDogg]

I guess what I wrote wasn't really clear. What I meant was when comparing the same engine with different HP levels, you will have different degrees of harmonics. I wasn't really trying to compare a F20C to a KA but thanks for clearing that up about the tq and rpm and what not.

[Boost_Veteran]

did anyone use a harmonic damper/fluidampr as an solution to the KAs $hitty harmonics? I dont think I did, or anyone else. All I know is I will be running one for my poor main bearings, it should help them out alittle.

[NateDogg]

Do you have a link or a contact to talk to about the Fluidampr? Is it for sure going in production or is this just a rumour?