Compression on this set up?
 

Compression on this set up?

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What would a good guess on a 302,.30,flat top pistons,61 cc chamber head's?My guess would be in the 10.1 range?Any thoughts?Another question is has anyone here delt with lowering compression on a set up like this.I know Cometic's are good but could I get this ratio down to say a 9.1?

whats the deck on the block? stock? heads new or are they deckd... and what thickness headgasket?....

my setup is going to be around 11.2-11.5:1 with a .043" HG and 64cc heads.

just to give you an idea...

I know you can custom order Cometics in just about any thickness you want... but that would have to be a THICKKK ass headgasket to get the CR down that low...

You could also have some1 massage the bowls on the heads... that will increase the combustion chamber....

LOL you should know bro it's Mikes motor.I really don't want to get all into the bowl work if possible.Not saying 9.0-1,but a low 9-1 would work.

The lower the better, dammit.

you fuckers have so many different motors, how am i supposed to know which combo your talking about...

I believe his was closer to 10:1... Im sure his heads are stock deck, as well as the block. and his is a felpro (non-metal) style HG...

Hahah yeah we do...between the two of us...we're gonna have like...4 Mustangs, 6 rearends, 3 blocks, 8 10-holes, 5 2/3 dashes :lol: , god, the list coudl go on. But yup, this is Mike's motor we're talking about.

LOL when there all done were gonna take them all over to my cousins and take pics,should be my coupe and 02 L,my brothers 86GT,my other brothers 91Vette,my cousins 92coupe,04 L,and 04 Cobra,my others cousins 86&89 GTvert's and my uncles 88 lx.Friend's are welcome too!

Anyway's,Mike's motor is 10:1 right?okay,with a set of Cometic's,what could I get this down to?Guessing of corse,I'll call Cometic after we pic up the car this week.

Oh Nick,you forgot about the 6 fenders,four doors,three hoods and all the other shit in my attic!!!:lol:I bet we could give Pat daddy a run for his money!!:lol:Want to go to the junk yard Sunday to see what we can find?:lol::lol::lol:

:lol: We get any more damn parts and Pat is going to be comign to your garage INSTEAD of the junkyard!

The best way to figure out exactly what the compression ratio will be is to mock-up the enigne and pour it. That will give you an exact number.

I used the following specs, which might be a little different than yours, and came up with 9.3-1 compression.

Bore_______4.030
Stroke_____3.00
Chbr cc's___61
Gsk Bore___4.100
Gasket_____.041
Piston______-5


I figured this out using a Fel-Pro head gasket and aftermarket pistons with larger valve reliefs. If you want to lower the compression more, stepping up to a .050 thick head gasket will lower it some more.