How much piston/pin weight loss before needing to rebalance ?

[travis]

I’m really rethinking my piston choice on this 351w I’m putting together. I don’t remember the bob weight the machine shop came up with, but the pistons/pins/rings/locks etc ended up at 778.7 grams. How much lighter can I go before I need to rebalance this mess?

[Mark O'Neal]

The "rule" used to be 20 grams heavier, 10 grams lighter.

I have no idea who wrote the "rule" or the validity it holds....but it's as good a rule as any. If you're going to lighten those bricks up, don't bother for a few grams. Any decent aftermarket piston should come in at least 100 grams lighter.

[Orr89rocz]

viewtopic.php?f=1&t=52400

Lol you asked this last year. What changed since then?

[travis]

viewtopic.php?f=1&t=52400

Lol you asked this last year. What changed since then?

Memory failure? Although this weight reduction will be significantly more than 21 grams I think

[PRH]

The question for me is.........In the context of what the intended use of the motor is...... will it really be worth anything?

NHRA stock eliminator pistons have to weigh the same as stock.
So, 340 mopars are running well into the tens with piston/pin combos approaching 900g(the trw L2316’s in my old 340 were 889g).

25 years ago I was running 10’s with my street/strip 448 that had trw replacement pistons/pins that weighed 1100g....... bobweight of nearly 3000g.

So, imo....... if they’re going in a mild street type 351 for a pick up or street cruiser...... spend the $$$ somewhere else.