lethal93ta

Ive been looking all over for a piston in the 8.5-9.0 range for a 383 but no one seams to make them, do I have to order a set of custom pistons or does someone make them.I really dont want to spend 800-1000 bucks like people are telling me.

97WS6SCharged

JE/SRP makes a 33cc dished forged piston for blown applications. It's supposed to be around 9:1 with 58cc LT1 heads.

lethal93ta

LT1 heads arnt 58 cc tho there 54 I want my compression down to atleast 9.0 im planning on running 12 lbs of boost.

97WS6SCharged

LT1 heads are supposed to be 58cc, LT4's are supposed to be 54cc.

http://store.summitracing.com/partde...131631-8&N=120 300014

lethal93ta

I already CCed my 2 sets of heads both of them came out to like 55 and till I mill them flush thell be around 54

97WS6SCharged

There's usually a bit of variation. Mine measured 57.something before they were milled. I just go by what GM says they're supposed to be. Anyhow, those pistons are about as dished as you're going to get with an off the shelf piston.

lethalz

I have 96 LT1 aluminium heads, and I've always though that are 54.4 cc

bunker

They are ussually 54-55 range if you cc them, after some milling etc.. mine are 51.5cc

97WS6SCharged

Like I said, there's usually some variation. I had to mill my stock heads quite a bit to make them straight after the head gasket blew. Maybe I cc'd the one on the high side. They're right around 55 now. My other set that Brent is working on started around 55 and now they're around 59 with all the porting and chamber reshaping.

arnie

Is this a thread on head cc, or pistons?
For head cc volume, do a search, this has been discussed thoroughly, in the past. Do not go by what GM states, but by what has actually been measured by those that state they have done so. You can even use 'arnie' in a search, if you like.

For pistons, do a search of the different mfrs., JE, SRP, TRW, Wiseco, Venolia, etc., etc., check their sites, and make a decision. From what I've found, a 31 cc dish is about the extent of what you may find. Crunch the #s, and if you need more volume, a bit of combustion chamber work, may be necessary.

lethal93ta

I really didnt want to mess with the combustion chambers, but im doing a full rebuild and would like to do a 383 and I need my compression down so I can run more boost on it.

97WS6SCharged

You could use the JE pistons I posted the link to above with a set of 76cc AFRs or the 64cc Trick Flow LT1 heads. That would get your compression down quite a bit.

Kraest

If you are trying to lower compression with the stock heads, JE makes alot of pistons to fit your application, and you can use a thicker head gasket (.049") ? I'd also mess with the combustion chambers.

Mike

arnie

The gasket determines the quench clearance. Although there have been those that have shown that not just tolerance, but success can be had with NO quench on a (very) high turbo boost application, for low to moderate (15-20#) boost applications, in street driven engines, I do not see that as an option. Though oem LT1s have been assembled with over .050" clearance, AFAIC, for a precision built engine, I consider anything over .040" as excessive.

rskrause

www.jepistons.com

Rich