headgasket/compression ratio

[97cLyPsE]

if i got an mls headgasket and got spacers for it would lower my compression ratio obviously. now if my compression ratio is already 8:1 and i add an mls headgasket with .50mm spacers what might my compression ratio be then? i would be able to run more boost along with the right fuel upgrades right ? im not a 4g63 guy, i have a 420a. i posted here because i know theyre are alot of car smart people in the 4g63 forum. plz no flames...........thanks guys.........ryan

 

[1fast97gsx]

what are spacers?

 

[DSMeclipse4G63]

relative compression can only be properly measured in the combustion chamber, you could do a compression test and get a rough estimate, but that wont be on the nose accurate. Yes getting a spacer will lower your compression, and yes you will be able to run more boost. But thats all relative....see a car with 9:1 compression running 15psi would be as fast as a car with 8:1 run higher boost. I dont know much about the internals of a 420a, but the 4g63 has a hemispherical combustion chamber allowing for high rpm high torque operation, in other words you can have 9:1 compression and still run 20+psi(depending on the condition of your headgasket of course).

what it comse down to is how your engine is setup and what style combustion chamber you have cause that makes all the difference in the world. But realize that trading compresiion for boost wont always make power...as the endresult is that to get the same power the compression ratio will be the same in boost(9:1 at 15psi and 8:1 at higher psi have the same comperession at full boost).
Andrew

 

[97cLyPsE]

relative compression can only be properly measured in the combustion chamber, you could do a compression test and get a rough estimate, but that wont be on the nose accurate. Yes getting a spacer will lower your compression, and yes you will be able to run more boost. But thats all relative....see a car with 9:1 compression running 15psi would be as fast as a car with 8:1 run higher boost. I dont know much about the internals of a 420a, but the 4g63 has a hemispherical combustion chamber allowing for high rpm high torque operation, in other words you can have 9:1 compression and still run 20+psi(depending on the condition of your headgasket of course).

what it comse down to is how your engine is setup and what style combustion chamber you have cause that makes all the difference in the world. But realize that trading compresiion for boost wont always make power...as the endresult is that to get the same power the compression ratio will be the same in boost(9:1 at 15psi and 8:1 at higher psi have the same comperession at full boost).
Andrew

ok supposse we have a pair of 4g63's layin around. say engine A and engine B are the same engine just set up differently. engine A has 8:1 compression and engine B has 9:1 which 4g63 would be able to take more boost? thanks for ur help andrew, ur helping me understand this a bit better..

 

[CanadianTalon]

They can both take the same amount of boost and horsepower if they are built with comparable parts, but the 8:1 motor will make substantially more power on low octane pump gas.