Headgasket Calculators?

[jdpolzin]

Ok, we have 2 different motors that we need to figure headgasket thickness on. Both are 4.1's, one is a .030 over and the other is a .040 over.

3.40 stroke crank (both)

.030 has 49cc at the deck, Champion Irons which i believe are 46cc in the chamber.

.040 motor hasnt been built yet so we can fill the cylinders yet. This motor will have the same pistons (Hypers) as the .030 motor but with a .040 bore. Deck heights should be the same on both blocks (assuming). This motor will have a set of GN1 Ported heads which I believe also use a 46cc chamber.

The Hypers sit down in the hole quite a bit and are rated for 7.9:1 compression. These motors do not have to be dead nuts set on a specific compression but we would like to try to get the compression as high as we can since we are using E85.

We plan to use Cometics on both motors. Given this little amount of information, can someone figure the compressrion ratio for me? Tom (Champion) said all he has in stock are .040 and .060 thick gaskets. I'm thinking we may want to try to drop down to a .027. I dont have the formulas to figure compression this way (using the CC of the cylinder instead of using piston specs).

Any help?

 

[big reazon]

http://www.kb-silvolite.com/calc.php?action=comp

 

[Major Nutz]

http://www.diamondracing.net/tools/

 

[turbonut85]

Replies are appreciated.....however we have figured out how to calculate the compression ratios as of now. But, even with a .027 cometic on the .030 motor....we come up with 7.91:1...is this a normal ratio for the 4.1 and hypers?? Seems quite low to me...IDK?? Are there any gains to be had by decking the block down .010 or .020 below stock deck height to boost compression ratios or at least to be able to run a thicker headgasket?? Drawbacks??

(.040 will be one of my motors if I ever quit blowing my $$$ on other things I don't need)