273 piston weight comparison

[65Val]

* 273 (2-Barrel).........530 Grams
* 273 'Commando'......569 Grams

Does a 39 gram difference require a rebalance?

 

[Scody21]

Yes. You really want to be within one gram. Zero is best.

 

[4spdragtop]

I've been curious about weight differences, and not to sidetrack, but my new TF balancer was 4 lbs heavier than oem. I didn't get it balanced.
So 39 grams difference on each piston would require what exactly for balancing?

 

[Scody21]

Taking weight off the heavy piston, most of the time from the underside. Depends on that your doing.

 

[4spdragtop]

Why would I not require a rebalance with a 4lb heavier harmonic balancer?

 

[Scody21]

Why would I not require a rebalance with a 4lb heavier harmonic balancer?

2 different topics at hand in this thread.

 

[66fs]

273 Balance was in the pins, not the pistons.

 

[Cuda Al]

I'm not sure they worry about the individual pistons.

My understanding they want all the piston and rod assemblies to match each other (all assemblies the same).
The crank then needs to be matched to the assemblies.
The damper/balancer needs to be neutrally balanced (by it self).

So yes, you will need to start over.
A good shop will weigh all the pistons and all the rods and then try to pair them up to minimize the amount of grinding.


Alan