Lt4 compression ratio
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Teching In
Joined: Apr 2004
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From: PA
Lt4 compression ratio Building a 383 for a friend using Lt4 heads.
Using the supplied pistons his comp ratio figures to be 11.8-1.
cam is .540 236°@.050 .586 .238@.050 on a 112° L sep
How high can he feasably go on pump gas with reverse cooled heads.
thanks
Using the supplied pistons his comp ratio figures to be 11.8-1.
cam is .540 236°@.050 .586 .238@.050 on a 112° L sep
How high can he feasably go on pump gas with reverse cooled heads.
thanks
Last edited by 1uke; Jan 2, 2006 at 02:39 PM.
Stock the LT4 was 10.8. How much compression he can actually run depends on chamber shape and quench as much as anything. Did the heads get ported and did the porter play with the chambers? LT4 heads are not that wonderful in stock form, good yes but not the pinacle of performance most of those new to the LT1 want to believe they are. Provided the cam has some overlap to bleed off low speed pressure and the quench isn't really wide it should work.
Joined: Nov 2001
Posts: 10,023
Likes: 6
From: LT1 land...the "409" of the 90s!
Actually you can run ALOT of compression IF you pick the right cam 
mine is 12.1 to 1 and Jims is 12.5 to 1.
i have a program that calculates what the Dynamic CR is. THAT is the important number 9.0 is the limit many say. mine is like 8.7 DCR.
If you post up all the important info we can calculate it. we will need the cam Base numbers as well as center lines and all the other CR info.
Maybe you can get SStrokerAce to chime in. I learned alot from Brett!
mine is 12.1 to 1 and Jims is 12.5 to 1.i have a program that calculates what the Dynamic CR is. THAT is the important number
9.0 is the limit many say. mine is like 8.7 DCR.If you post up all the important info we can calculate it. we will need the cam Base numbers as well as center lines and all the other CR info.
Maybe you can get SStrokerAce to chime in. I learned alot from Brett!
Joined: Nov 2001
Posts: 10,023
Likes: 6
From: LT1 land...the "409" of the 90s!
