head gasket

[mally69]

ok suppose i have 10.82 compression with a .039 head gasket,   if used a .042 head gasket how much lower would the compression be with a .042 gasket 

[471_Magnum]

Need more info. Gasket volume is only one factor in CR. Bore? Stroke? CH? Piston dish or dome volume?

Note that the Fel Pro 1009 is listed at .039" and 9 cc.

Mopar Performance sells the same gaskets in a two pack and lists them at .042". Sorry, don't recall the part number.

If these are the actual gaskets you are referencing, the answer is "zero".

[firefighter3931]

Assuming both gaskets were the same bore diameter there would be very little difference in static compression #'s.

If you're looking to pull some compression out of the motor then you have to go with a larger bore diameter/thicker head gasket, a larger combustion chamber or a combination of the two...depending on how much you want to reduce.



Ron

[471_Magnum]

What are you trying to accomplish? Are you working with iron heads or aluminum?

[aifilaw]

well, first of all, your head gasket thicknesses are kind of interesting...
in my experience, various head gasket thicknesses are, 0.04 0.06 0.08 0.10
and I typically never run anything thicker than a 0.06 because it opens you up to the possibility of an easily damaged head gasket.

a 0.02 difference in head gasket thickness is equivalent to about 0.6 static compression ratio dependent on the bore

[mally69]

ok well heres what i have  i have 440 source's  512 stroker kit. Im already bored .30 over the heads are indy ez-1 heads that are 75 cc.  440 source says their compression numbers are with a .039 head gasket and with that kit a 75cc chamber = 10.82 compression,   and the ones that come with the kit that i have are .042 , my block was decked 5 thousandths above zero deck..  im trying to figure out my compression basically

[Rolling_Thunder]

Flatout gaskets makes copper head shims if you think you need to drop some points to stay on pump swill   

[Chryco Psycho]

Use Cometic head gaskets , you need them with alum heads on an iron block so they will not fail & they are available in up to .100 thick

this should help you http://www.csgnetwork.com/compcalc.html

[mally69]

thanks for that link,  if i use a 4.380 bore gasket IF i did the rest correct i should have 11.06 compression   i was trying to get as close to 11.1 as i could and  i think  got it.

thanks guys

[Runner]

you dont "need" cometic gaskets to run an aluminum head on an iron block.   people were running iron blocks and aluminum heads without issue long before they mls gaskets came out. 

    im running the cheapo 8519 felpros with iron block and aluminum heads without a problem for over 2 years now.