3 different stock 3100 pistons

[SappySE107]

I expected 2, for the change in rings, but not 3.

96 3100 beretta has 2 1.50mm rings and a 4.00mm ring. 1.480 CD .260 x 2.865 dish and a .9055 pin

99 lumina has 1.20mm 1.50mm and 3.00mm ring, 1.480 CD .260 x 2.865 dish and a .9055 pin

2000 lumina has 1.20mm 1.50mm and 3.00mm ring 1.467 CD .270 x 2.75 dish and a .9058 pin.

That means the vin J doesn't have the same quench properties of the vin M motors. Typo, or verification (i used rock auto for these specs).

[SappySE107]

2002 3400 pisto 1.20mm 1.50mm 4.00mm rings 1.478 CD .275 x 3.180 dish and a .9059 pin. what is up with these pins and why a 4mm ring! All I wanted to do was list pistons on the store

[robertisaar]

so what all does this mean to us? there are more efficient pistons depending on year and vehicle, even with the same motor?

[SappySE107]

It means I am confused by the changes. I knew the rings changed, but not the amount that the piston sticks out of the hole or the pin diameter, however small the difference.

[Superdave]

I'd just find the newest version and offer that with the matching rings.

if i'm reading that right, it looks like the '00 pistons pop out .013 less but they adjusted the dish to make up for that. Kind of a strange revision...

[3400-95-Modified]

Does this screw with the Diamond pistons? I'm assuming if you have these older rods you would have to match the years to what size pin comes with the Diamonds... Speaking of which... What pin size did they go with, IIRC you stated it was a floating pin too? vs a pressed in one.

Pin difference of .0004 is next to nothing tho... that's almost a tolerance amount...

[SappySE107]

Well I only have 3400 diamond pistons. I noticed the pin diameter is different across the board within tolerances as you said, and its been the same rods since 1980 so I don't know how they can really change that.

I only listed the latest revision for these 3100 pistons, and should have them visible on the store today after I create the piston sections. I don't know what to do with the iron head pistons just yet cause I don't have a gen 1 section at all. I may throw them in the other sections and explain the compression/quench with using them on the aluminum head motors.

[3400-95-Modified]

Well I only have 3400 diamond pistons.

Good point, I missed that this was for 3100's