Has anyone weighed a stock L98 piston? Curious what the weight is.

I'm running stock crank/rods, but 610 gram pistons. Curious how far off balance my setup is.

-- Joe

 

I just measured this recently, but I'm going from memory here so don't hold me to the exact gram. I recall measuring a stock 350 piston at 603g with a wrist pin of 145g. You're REAL close. You shouldn't have any problems with balance.

Remember to check the wrist pin weight (some pistons use thicker wrist pins that can REALLY throw things off if you don't take them into account). ~145g is what almost all stock 350 wrist pins weigh. Also, if your new pistons use thinner rings (1/16" vs. 5/64" stock) you might shave a few grams of total weight off thanks to them as well.

I have built motors further out than this without rebalancing and never had a problem. Obviously, if you want the best possible power and longevity from it you should get the whole bottom end balanced anyway.

 

OK. To be perfect though,you could shave 7 grams off each piston then? Hrmm..

Thanks!

-- Joe

 

Don't hold me within 7 grams. That's like the wieght of 7 of the smallest size of paper clips. I bet a set of stock pistons probably vary more than that from lightest to heaviest. If you were off by 35 grams or 50 grams, yeah, it might be time for a re-think of the whole situation. But for 7 you move on with life and don't look back.

 

Checked balance on my last engine. Piston and rod assemblies ranged from 1343.5 to 1354 grams. Did notice that the lightest and the heaviest ones were paired on the same journal so GM must make some effort to get them in balance.