Will my LT1 have to high a compression ratio?
04-14-2009, 10:18 PM
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Will my LT1 have to high a compression ratio? Hi, I have an LT1 build up and I have done my home work and I think it should be good.
My compression ratio with a .030 over bore, zero deck, and a compressed gasket .039 I'm supposed to have 10.7:1 with a 64cc head.
My heads are 58cc Patriot 195s my block is not decked so they are down in the hole a bit. If it was at 0 deck and same gasket thickness and cc it takes up it would be like 11.4:1.
Is my homework right and with the aluminum heads and the LT1s reverse cooling I should not have problems on lets say 91 to 93 premium gas for Illinois?
Or should I be sending my heads back and see if I can get the 62cc chamber?
I know I have not done the dynamic or static compression ratio just going on numbers.
Might be able to have my chamber cut back or valve un-shrouded to gain a few cc.
It has 2 valve relief -5cc pistons it is a street motor for my convertible 95 Z28.
58mm throttle body 32lbs injectors, long tube headers, no egr., off road exhaust no cats. 2500 stall, 3.25 gears I think stock.
Cam
Intake center line 109
LSA 113 + 4 degrees advance
Lift Intake with 1.6 Rockers .564
Lift Exhaust with 1.6 Rockers .560
Duration @ .50
Intake 238
Exhaust 244
Tell me what you think.
My compression ratio with a .030 over bore, zero deck, and a compressed gasket .039 I'm supposed to have 10.7:1 with a 64cc head.
My heads are 58cc Patriot 195s my block is not decked so they are down in the hole a bit. If it was at 0 deck and same gasket thickness and cc it takes up it would be like 11.4:1.
Is my homework right and with the aluminum heads and the LT1s reverse cooling I should not have problems on lets say 91 to 93 premium gas for Illinois?
Or should I be sending my heads back and see if I can get the 62cc chamber?
I know I have not done the dynamic or static compression ratio just going on numbers.
Might be able to have my chamber cut back or valve un-shrouded to gain a few cc.
It has 2 valve relief -5cc pistons it is a street motor for my convertible 95 Z28.
58mm throttle body 32lbs injectors, long tube headers, no egr., off road exhaust no cats. 2500 stall, 3.25 gears I think stock.
Cam
Intake center line 109
LSA 113 + 4 degrees advance
Lift Intake with 1.6 Rockers .564
Lift Exhaust with 1.6 Rockers .560
Duration @ .50
Intake 238
Exhaust 244
Tell me what you think.
04-14-2009, 10:23 PM
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Stock is 10.4:1 w/ 56cc so you're more than fine. Stock with .026 gasket puts you into the 11.1:1 area, which will have no problem with 91oc. Some on here have well over 12:1 running pump gas. On my stocker (which has been rebuilt and I have zero clue as to what the CR is) has no prob with 87oc 
