Like the title says what is considered a light piston and pin?
1. heavy weight piston and pin
2. medium weight piston and pin
3. light weight piston and pin


When looking for pistons I have seen piston weight at 635 for the piston and 163 for the pin
583 piston 163 pin
558 piston 142 pin

What affect does each gram have?
How many grams does it take to see real world affect on engine longevity?
Thoughs on piston and pin weight?

 

600g piston plus pin would be light. Each gram? well, I wouldn't quibble about every gram, but a difference of 200g is almost half a pound. The effect is seen most prominently at overlap, where the piston is coming up without compression slowing it down. The rod stretches from the weight hanging off of it, and that is when the piston hits the head if you don't have enough clearance built in.

 

Here are some piston weights for comparison:

Speed Pro L2323F= 684g
Icon KB886= 557g
SRP 206072=574g
Ross 38720=574g

 

Remember the pin and rings weigh more on the Speed Pro as well.
Plus you can use the lighter .984 Mopar pin instead of the heavier .980 Olds/Pontiac pin on any of them. The difference is approx 30 grams.

 

If you are willing to deck the block an additional .055" or lower compression, you can bush the rods to .927" and use plentiful and inexpensive SBC race pistons and pins in full floating configuration. Such a combination from Mahle, for example, will be a bit under 600g piston and pin.

 

Thanks for the replys they are very helpfull.