8.5 c/r and 0.50 thick head gasket

[cbr600teardrop]

like the title says ill be running 8.5 c/r pistons and 0.50 thick head gasket what will this do to my c/r

 

[cbr600teardrop]

bump

 

[viperlp01]

Why such a thick head gasket?? There is a formula that you can use to find out the C.R...

 

[need2boostpsi]

I lost 8PSI on my compression test across the board when i upgraded to 272's 1mm O/S and a Mitsu MLS Head gasket

 

[92awddsm]

With a 1/2"thick gasket(.500") I would say compression ratio should drop to somewhere around 5:1
Probably even less. Im not gonna waste my time doing the math on this.

 

[tkelly27]

Engine Compression Ratio (CR) Calculator

I was going to do the math for you, but then you bumped your thread : (

If you really mean .5" thick, you should worry about cam timing about as much as compression.

 

[cbr600teardrop]

well im having my keydiver chip reprogrammed and wanna get the math right be for i send it out

 

[sbengineering]

I think he meant fifty thousandths. 0.050. With that said, and all other factors in the normal range, the CR will be around 8.4:1.

 

[cbr600teardrop]

85.5 Mls .051" C4233-051 85.5 pistons stock head other than bc 272's

 

[tkelly27]

I'm not really sure what's so hard about using the calculator I linked you to. Do you really have a .5" head gasket, or did you mean .050?

I used .025 as the starting, and wound up with a CR difference of .02 when going to a .05 head gasket.

 

[cbr600teardrop]

should i just get my machine shop guy to do all the math cause my block pistons and head is still up there?

 

[tkelly27]

If he is building your whole engine he should have that information for you.

 

[cbr600teardrop]

na i just brought im my motor to bore and fix some broke exhaust studs and check every thing ill be putting it all together

 

[cbr600teardrop]

its sad when i went to school for automotive tech and i cant figure out what c/r on my motor is but my school didnt go that far in to it

 

[92awddsm]

Just tell jeff you have stock compression for the 6 bolt. The chip will be more than close enough for you setup. Your not gonna even get to 8-1 compression so the aggressive 1g timing maps wont effect you at all.