3.4 pistons?

[ForcedFirebird]

with the camaro pistons you have to remove a good amount of the cc chamber to get the combust ration down. as ive learned from my own research and the pics that someone posted comparing the iron head vs alum head.
8cc's vs 27cc for the 3400

Yep, and with my current 3.1 (12cc) pistons, the cr will be a tad under 12:1. Just on the fence about doing this head swap and running straight race gas and low boost, mowahahaha

[geldartb]

im aimin for around an 11.5.1 cr. its not my daily plus its getting a nice cam from the store on here.

[Alxsmt]

i have the 91-96 lumina/monte dohc pistons, what do u mean by size? they are standard bore if thats what you are asking

BTW i was only to come up with 12.1x:1 compression on the cr calculator with the stock dohc pistons, any one have documentation of what the compression ratio would be?? is that correct? i would like to take some proof in so they dont fight with me

[Alxsmt]

is it possable the deck clearance is .05???? thats what my friend got when he measured it, that would make the compression 10.8:1....

can any1 verify this for me???

[SappySE107]

DOHC pistons come up flush to the deck surface. No way its .050".

[Alxsmt]

ok, he just told me he wasnt able to get the correct reading at the top of the piston.... do u think that i can make 10.5:1 with these pistons??? safely


long story, the machine shop tired to BS with me... i dont trust them now AT ALL, to do ANY work

[MATT2007]

send or take them back and tell them thay are stupid and you want your money back thats what I did when I got dished insted of flat tops for my 350 by the next week I had the right pistons

[Alxsmt]

ok i took my pistons to a machine shop about 3 hours away from my house (friend and uncle knows the owner) i had him measure to see if he thought it would be safe to mill them down a bit. there at the bare minimum already.... and there isnt too much they can do to bring the compression down with combustion chamber work (not too much he would feel safe grinding off) monday im taking them back, if they dont give me a refund they are going to court.... im am comsidering just getting some stock 3400 hyperutectic pistons and MABY run a few pounds of boost in the future if its not fast enough (since the compression would be low)

[Superdave]

ok i took my pistons to a machine shop about 3 hours away from my house (friend and uncle knows the owner) i had him measure to see if he thought it would be safe to mill them down a bit. there at the bare minimum already.... and there isnt too much they can do to bring the compression down with combustion chamber work (not too much he would feel safe grinding off) monday im taking them back, if they dont give me a refund they are going to court.... im am comsidering just getting some stock 3400 hyperutectic pistons and MABY run a few pounds of boost in the future if its not fast enough (since the compression would be low)

It's still 9.5:1 that's really not bad at all. Moonwell is making TONS of power on the stock pistons...

[Alxsmt]

i have 3500 heads, according to the calculator it would make it 8.82:1

[Superdave]

i have 3500 heads, according to the calculator it would make it 8.82:1

in that case.. ouch


I've got an extra 3400 piston laying around, maybe i'll see if my old theroy works..

I'd like to shave .020" off of one and then CC it.. that should bring it to 0 deck, then you could use iron head gaskets.. smaller dish/thinner gaskets should bring it up decently...

[ForcedFirebird]

in that case.. ouch


I've got an extra 3400 piston laying around, maybe i'll see if my old theroy works..

I'd like to shave .020" off of one and then CC it.

Wouldn't that make the ring land thin?

8.82:1 with 20psi......

My car is only 8.5:1

[Superdave]

Wouldn't that make the ring land thin?

8.82:1 with 20psi......

My car is only 8.5:1

it's .197 from the ring to the top of the piston, .020 should be safe to take off...