LS1_PNYTAMR

iTrader: (1)

okay.. im researching a set of forged pistons and forged stock sized rods to run with stock crank..

but how do u tell if future cams will clear with aftermarket pistons or stock heads? just dont wanna buy something then buy a large cam, or heads and say oh ****, thats not going to work or get pistons with a 10.5:1 comp with stock heads and then buy aftermarket heads and say oh hell now its 11.5:1 or what not ya know....

if it matters, id prolly get pistons,rods, tsp 233/239 cam or f13 cam at the same time, then later on after i got more money, get afr heads or what not.



just a young car guy trying to learn a few things, thanks.

LS1_PNYTAMR

iTrader: (1)

also will the patriot stage 2 ls1 heads..... change the compression any???? i know ls6 would or 5.3.. but there ls1's just basically a port job on stock heads right, does that make a difference?

jrp

iTrader: (16)

6.098 rod and 3.898 flat top piston with 2cc valve reliefs will clear anything thats out right now. compression will be slightly lower with the valve reliefs as its like adding extra volume to your head chamber. you'll only increase compression with your piston if you get domes. ls1 heads will not change compression unless you mill them.

i've got diamond forged pistons w/ 2cc valve reliefs and 6.6 domes and my heads have been milled .020, cam is a 238/236 .586/.589 112+0 w/ a .045 gasket and i have plenty of clearance. forgot the exact amount off the top of my head though.

CAT3

iTrader: (9)

Compression ratio will be affected by the thickness of the head gasket, and volume of the cylinder head combustion chamber, as well as piston design.
When you buy pistons they normally say xxx cr with xxcc heads. There is a sticky at top of this section with CR info as well. If you build the bottom, lets say using flattops at 11:1 cr with 66cc head (assume thats your stock cc) then you go to buy heads, you ask what the chamber size is, if they are stock ported heads, make sure they are not milled. And use the correct thickness gasket, there will be no CR change! If you however buy 6.0l heads unmilled your compression will drop, and vice versa if you buy 5.3L heads milled .050" your cr will go thru the roof!
Cam selection, is relative to the clearnace available, and many piston makers include valve reliefs cut into the piston already. You can search through threads to find similar setups which will get you into the ballpark. Worse case scenario, you end up not having good enough clearance and have to cut reliefs in-car. You can also measure everything once the bottom is done, and heads are in, using the test springs and dial indicator to find clearance and then order a cam, which will slow you down on buildtime. Or you can give all your engine build particulars to a sponsor and they should be able to assist you in selecting the right sized cam, or have one ground for you. Jason or Trevor can dbl check, but I am sure the 233/239 was designed to clear with stock height assembly, as well as the F13.
Porting doesnt change the CR, as long as they are 5.7L heads, unmilled and you use factory/stock thickness gasket you will be good.

LS1_PNYTAMR

iTrader: (1)

okay.. i was gonna run something like this 6.098 rod and 3.898 flat top piston with 2cc valve reliefs.. proly want use 6.098 rods tho.. i thought u wer supposed to run 6.125 and 3.905 or something??? this way my machine shop can put a slight hone to the block to make sure the rings seat properly right? hell if 6.098 and 3.898 is just as good no reason to change i guess right.

if i got any heads they be afr 205's and i guess the dont come milled, and i woudn't have them done that way. from what ive seen the look awesome the way they come.

just wanna make sure if i buy a 233/239 tsp cam or f13 or something in that size range, and then change pistons to something like above with afr's untouched, it would not screw things up... im kinda money limited, so id buy cam, then bottom end, or heads then bottom end ect.. so i have to make sure what i get is compatible with future plans ya know.

thanks for the 2 replys.. really helped.

CAT3

iTrader: (9)

Safer bet is to hone the cylinder out for the new rings to seat better, but from reading, some have gotten away fine with new pistons, rings and rods in stock untouched bottom.

Good luck

Charlie