Dohc rotating assembly balance

[stang8762]

Im in the process of tearing down my engine w/ My engine builder who i trust b/c he is a family friend .. We were talking the other day about when he goes to balance 302 /351 based rotating assembly he said that at his shop they usually balance the flywheel , clutch and damper together w/ the rotating assembly on most motors for the best balance. Is this true w/ the modular motors or since they are internally balanced its done a diff way?


I know the dohc engines are internally balanced how do you get away w/ putting on a flywheel/ clutch and damper and its still balanced

please school me im trying to learn the ins and outs of the modular motors ..

 

[fastback brian]

4.6 go internal and for the most part you dont need the crank pulley or flywheel.. typically those modular part are zero balanced from who ever makes them.. now the pushrod guys need the unbalanced parts to get the assembly balanced.. the balance machine isnt gonna set an assembly to 28 ounce or 50 ounce unbalance, they are set to go zero....

 

[OldSVTGuy]

I would trust your engine builder. While these engines are supposed to be zero balanced, the factory does not balance to the specs a custom builder would. And, if you are changing rods/pistons, you need a new balance because these are not factory parts. I prefer to have any new re-build re-balanced with the damper you are going to use, the flywheel you are going to use and the pp you are going to use. If just makes sense. And, it doesn't cost that much extra.

That, however, is my .02. Good luck with the re-build.

 

[stang8762]

Yeah im definalty going to give him my balancer, flywheel and pressure plate to make sure the rotating assembly is perfect , i was just curious what if i have to change clutches down the road ? will it throw everything off ?

 

[na svt]

Yeah im definalty going to give him my balancer, flywheel and pressure plate to make sure the rotating assembly is perfect , i was just curious what if i have to change clutches down the road ? will it throw everything off ?

the damper, flywheel and clutch should have a zero balance. If you change the clutch later you could have it and the flywheel balanced together to ensure all is good. Not many people go to that much trouble but it's not a bad idea to do so if you're spinning the shit out of the engine.