SBC Head ?s

[cwn anwyn]

I replaced a blown head gasket(or cracked head) with one I got from a guy on colorado4x4. I would have put both of his on but one of the valves is messed up. I had good compression on the other side. So I slapped the one head on. The only difference in the casting numbers is the new one is an X. +10cc on the intake. Will running one X head and one normal head affect anything. Its only temporary till I can get both heads redone. Any info would be great. Thanks

Z

 

[1979jimmy350]

not having the same compression ratio will cause your engine to be more unbalanced and make uneven power. you would have to run the numbers to get the comprssion ratios and what the difference is. A small amount of difference should not be to bad.

 

[cwn anwyn]

Hey thanks for the input. I dont think it will be a big difference if any on the compression ratio's.

According to this table, http://www.thedirtforum.com/castings.htm
397348768-791.94/1.50
& 2.02/1.6165-33076 CC Chambers
X casting has 10 more intake
cc volume.

the only difference in the heads that I have is the x. 10 more intake cc's. Both have 76 cc chambers(75 cc on mortec). Will this matter for a couple of weeks running. Thanks

 

[TorkDSR]

the size of the valve wont affect the combustion chamber...

but if the combustion chamber is a different size that would get weird

 

[R72K5]

better get matching heads on that engine...

make sure ones not been milled more than other too...

larger valve head can affect volume displacement, so can seat and valve head margin wear- or lack thereof, IE distance valve head is protruding into chamber.. or not., it is measured in cc's
a cc is not very much..

common sbc head combustion chamber volumes are 58, 64, 72, theres some others too, oddball ones,



good luck..,