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View Full Version : Piston Balancing

Rockin' Al
04-09-2007, 09:54 PM
Chris,
When you are lightening pistons, how important is it to balance the weight of each piston after machining? What is a good number for the weight difference between the heaviest and lightest piston?

I have access to a scale that can measure to 0.05 grams. Is a range of 0.25 grams good enough? Is that overkill?

Thanks,
Rockin' Al Miller
fast66
04-09-2007, 10:43 PM
On everything we do the pistons and rods are balanced within a 1/2 gram. I know most cup teams and pro stock teams go with 1/2 also anything less than that is splitting hairs due to oil being pushed around the crank case. You still going to run NSCA or moving classes with your Vette?
Ken Schertz
04-09-2007, 10:57 PM
Al would have to weigh 3512 with the Vette. Hell Davis could drive, with Huber riding shotgun and Al and I in the back seat yelling GO! GO! GO! LOL
Chris Uratchko
04-10-2007, 08:21 AM
Within 5 grams from heaviest to lightest engine won't know the difference.

When I am balancing my own I just shoot for around 1 gram.

Everyone has their thing I suppose.... crankshaft balancing I have found is not an exact science and very subjective... unless you talk to someone who balances crankshafts for a living and then .2 grams will kill the whole deal.

I don't mind folks worrying about .2 grams it certainly don't hurt.
388Monte
04-10-2007, 09:55 AM
Like Chris said, 5 or less and I wouldnt have a worry. Your going to have that in oil from piston to piston as the motor operates. These guys that balance within a tenth of a gram kill me. If you do lighten the pistons to get weight close from one to the other, PLEASE DO NOT REMOVE MATERIAL FROM THE BOTTOM OF THE PIN BOSS, Your taking the stucture right out of the piston. You can radius the out edge of the pin boss, just do not take it from right under the pin hole.
Rockin' Al
04-10-2007, 01:44 PM
Al would have to weigh 3512 with the Vette. Hell Davis could drive, with Huber riding shotgun and Al and I in the back seat yelling GO! GO! GO! LOL

Ken,
The easiest way to get to 3512#s would be to get you, Mikey, and Rockin' Al Sr together for a weekend and then use the empty beer cans as ballast.