Olds heads
#1
Olds heads
Hi,
I came across a set of Olds heads for 20$, needless to say I snapped them up. I was told they were from a '68 350. How can I ID them to be sure? My plan is to have them rebuilt and then replace the tired ones on my 68 Cutlass ( also will rebuild the short block).
In the same vien, I was reading my Motors Manual and see that 68 350 have a couple different compression ratios listed. Are the differences soley related to the combustion chamber size? and again, is there a fairly simple way to ID which is which?
Any minor performance tips for these heads would be appreciated too!
Thanks!!!
I came across a set of Olds heads for 20$, needless to say I snapped them up. I was told they were from a '68 350. How can I ID them to be sure? My plan is to have them rebuilt and then replace the tired ones on my 68 Cutlass ( also will rebuild the short block).
In the same vien, I was reading my Motors Manual and see that 68 350 have a couple different compression ratios listed. Are the differences soley related to the combustion chamber size? and again, is there a fairly simple way to ID which is which?
Any minor performance tips for these heads would be appreciated too!
Thanks!!!
#3
It is very easy, they will have a large number on the corner, in this case if it is a 68 head it should be a "5" Cylinder head volumes were the same, compression ratios were changed by using a different sized dish in the piston.
#4
Excellent help captjim, thanks! These have a "8" so I suspect they are from a 73-76 ( found a cool website to help in ID'ing)and not a 68. I seethe ones in my car now are "5", is there a way to determine the compression ratio without removing the heads to see the pistons?
Thanks again.
#5
I see the ones in my car now are "5", is there a way to determine the compression ratio without removing the heads to see the pistons?
Thanks again.
Thanks again.
#6
To add to Joe's post, the factors determining Cr are the piston dish, depth in the hole, gasket bore and thickness, and cylinder head volume. There is a tiny amount between the piston and the top ring. So, there are several variables. If the engine has never been apart, the Cr should be in the low-mid 8.xx to 1 neighborhood. But, that is just an estimate. Read this if you care to,
http://www.oldspower.com/vb/showthread.php?t=36717
EDIT Obviously, bore and stroke are primary factors, too. In the case of an Olds 350 it is 4.057 x 3.385.
http://www.oldspower.com/vb/showthread.php?t=36717
EDIT Obviously, bore and stroke are primary factors, too. In the case of an Olds 350 it is 4.057 x 3.385.
Last edited by captjim; July 29th, 2009 at 12:33 PM.
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