My Pete rebuild

[Squish099]

(12-30-2021 )Nostalgic Wrote:  

(12-30-2021 )Squish099 Wrote:  Just remember.. The faster something spins the more critical balance is.. 2000 rpm max is a whole hell of a lot different then 8000.. And guys balancing to 0.05 gram are on big and small block ford/Chrysler/gm.. Parts are much smaller spun at much higher rpm. Usually the crank and is spun balance with Bob weights too so the crank counter weights match the assembly that's attached to them... Balancing rods and pistons do squat if crank ain't balanced too..

I realize it's a long way to 8k, but saying 2k max is a way too controlling statement lol. Bob weights aren't used to balance the crank like in a v engine. Inline 6 is a inherently balanced spinning triangle with 3 throws 120* apart, and stays that way as long as everything you bolt to it is balanced as well. Of course I'm betting on the hope that Cummins balanced the crank correctly lol.

Yes most I6 cranks are neutral balanced as far as firing harmonics. Your going through an awful lot to balance rotating mass. They do spin balance I6 cranks with Bob weights on performance built motors to get counter weights the same as piston/rod weight on that throw..