B16 Balancing

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steacy91

New Member
Had my b16 bottom end built with eagle forged rods and supertech pistons, new acl bearings, does balancing the block entail just matching the piston/rod combo's weight for each cylinder, or is there more to it, i got the block back built, pistons, rods and crank installed, tried doing some research but couldnt find any definate answers. Should I be ok to go ahead and put it all together or do i need to have some balancing work done first ?
 
There should be more to it. The crankshaft will be balanced with the flywheel, pressure plate, and crank pulley attached to the end of it to eliminate possible vibrations. This is critical because a lot of aftermarket clutches are way different than stock weight.
 
The block doesn't get balanced, I suppose you could say the "short block" get's balanced.

The most common method today is by using a process referred to "Noramalizing" or weighing each rod, wrist pin, piston assy and matching the weight of the set to the lightest one. Then they balance the crank by itself. Balance flywheel on the crank and then the pressure plate mounted to the flywheel. and the harmonic balancer on the crank.

The counterweights on the crankshaft provide a centrifugal solution to the mass of the rod, and also to the reciprocating mass of the rod/piston assy. The offset used is not 100% and because it's centrifugal -vs- reciprocating there will always be offset error and vibration. It's about making the offset error the same for each cylinder.

You need to have the balancing work performed first. I'm surprised the machine shop that did the work on the block didn't discuss that with you. You might want to ask around a little about them, perhaps they aren't the ones you want doing the work.

The machine shop should have discussed your objectives and given you feedback and consultation on your project. ;)
 
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Ok cool, yeah the guy who did the work mentioned balancing when i first talked to him, said he couldnt do it himself but he had a shop he deals with that could, but he didnt have the flywheel and clutch and all that. Is the head ok to be installed when its being balanced ? thanks.
 
No, gotta have it torn down. They will pull the piston/rod assy's and match the weight of them to one another via the lightest one. That process is called "Normalizing" - then, any piston/rod can be put into any cylinder when assembled. Also, matches everything up in terms of the crank to piston relationship.

Yeah, the shop that did mine sent the cranks out for balancing and did the rod/pistons in house.
 
Recommend you get the crank, flywheel, balancer (crank pulley) & pressure plate done to complete the process.

Normalizing the pistons/rods will probably help without doing the crank, that assumes the crank is close. Best to have it all done.
 
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Talk to them about the flywheel, clutch, and pressure plate, as well as the crank pulley.

EDIT: beat me to it lol
 
^ Yep - smoked ya on the keyboard! Got the Hole Shot. That's ok, your hatch would incinerate mine!!! :)
 
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