quik01ss

iTrader: (24)

does anyone make a larger cc chamber head then stock 72cc looking for 80cc chamber if not changing piston...

JPH

iTrader: (2)

Have a cylinder head guy open the chambers up a few ccs and play around with gasket bore/thickness to achieve your intended SCR is about your only choice.

bww3588

iTrader: (49)

What compression ratio are you shooting for? What pistons do you currently have?

quik01ss

iTrader: (24)

4.005 -8cc piston 60cc chamber right not have 11.5 cr want to get to 9.5 cr but i think its just gona hav to get a dished piston

JPH

iTrader: (2)

Yes, I would have to say it would. What is the SCR with a 72cc head?

bww3588

iTrader: (49)

With an 8 cc dish in your current piston and 71.5 cc chambers you should have what you need.

quik01ss

iTrader: (24)

with a stock 72cc 317 head it is 10.13cr just gona have to switch out the pistons to -28cc get me to 9.3cr

bww3588

iTrader: (49)

with a 28cc dished piston, assuming you are using stock thickness gasket, you will be at about 8.3 to 1

by my calculations, providing you use a .040 gasket with a 4.060 gasket bore, you will need a 20 cc dished piston, or with a 28 cc dished piston you will need to mill your heads to 63cc's

JPH

iTrader: (2)

Give me your current piston cc spec, head cc spec, gasket spec and bore/stroke and deck height(if known) and let me calculate your SCR. Got to many different answers going on here.

quik01ss

iTrader: (24)

Its 4.005 bore

Bore.......4.005

Stroke....4.00

Piston...... -32 cc

Head......60 cc

Head gasket bore....4.100

Head gasket thick....0.53

Meased piston out of hole ....0.005 out

Scr.......9.04 :1

bww3588

iTrader: (49)

again, assumed measurements...how do you know he is using a 4.100 bore gasket? how do you know they are .005 out of the hole?

I'd say good thinking tho. looks to be ballpark, but never 100% accurate until OP gives exact measurements.

quik01ss

iTrader: (24)

I am the OP......lol... im building my own motor again ....the n/a style 403 i built yeilded a .005 out hole pistion so using the same company piston just -32cc this time give or take some thousandths.... head gasket is ls9 thats there specs....

bww3588

iTrader: (49)

Sorry, I was a bit...intoxicated last night.