How far can you deviate on piston weight before needing to rebalance?

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travis
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How far can you deviate on piston weight before needing to rebalance?

Post by travis » Wed Feb 14, 2018 11:29 pm

For a purely street/utility use 351w that was balanced with a set of 790 gram pistons/pins, would you rebalance after to going to a 21 gram lighter piston and pin? This thing will rarely, if ever, see 5000 rpms. I am concerned about long term durability and having a smooth running engine

rustbucket79
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Re: How far can you deviate on piston weight before needing to rebalance?

Post by rustbucket79 » Thu Feb 15, 2018 12:13 am

You'll never notice the difference but if you can afford, especially if you need to replace a flex plate or resurface your flywheel or replace your harmonic you may as well balance. Much better than wishing after the fact. #-o

Ericnova
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Re: How far can you deviate on piston weight before needing to rebalance?

Post by Ericnova » Thu Feb 15, 2018 12:14 am

Being lighter like that wouldn't even make me blink. Run it.

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MadBill
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Re: How far can you deviate on piston weight before needing to rebalance?

Post by MadBill » Thu Feb 15, 2018 3:03 pm

Lots of engines are deliberately 'overbalanced' by more than that.
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.

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