PAC 1218's with a F13????
02-10-2010, 09:35 PM
#2
230/232 and .595/.585 on a 112 LSA
are the 1218's enough or would you go 1518's?
Will also be swapping in a set of 243's off a c6 vette. Would like to know how much I can shave off to raise the compression a little when I clean them up and install the valve springs at the machine shop. I was thinking .005-.010??? The 243's have 64.45cc chamders stock and I would like to take them down to a little over 60cc.
might need a 114 lsa to clear???
are the 1218's enough or would you go 1518's?
Will also be swapping in a set of 243's off a c6 vette. Would like to know how much I can shave off to raise the compression a little when I clean them up and install the valve springs at the machine shop. I was thinking .005-.010??? The 243's have 64.45cc chamders stock and I would like to take them down to a little over 60cc.
might need a 114 lsa to clear???
02-11-2010, 06:31 AM
#5
I found this on performancetrucks.net
So you want to figure out how much to mill:
It takes about .005" milling of the block deck to remove 1cc of volume. It takes .007" milling to remove 1cc from an LS1 head
Simple Milling Math:
You have a stock 66cc chamber and you want to get down to 63cc
66-63 = 3. You have to remove 3cc's
.007 x 3 = .021. So to get your 66cc chambers down to 63cc you'd have to mill ~.021.
You can also do the reverse, say you want to mill a head .030 to figure out how many CC's that removes you take .030 / .007 = ~ 4.28. Milling a stock 5.7 head .030 puts your chamber at ~ 62.
It takes about .005" milling of the block deck to remove 1cc of volume. It takes .007" milling to remove 1cc from an LS1 head
Simple Milling Math:
You have a stock 66cc chamber and you want to get down to 63cc
66-63 = 3. You have to remove 3cc's
.007 x 3 = .021. So to get your 66cc chambers down to 63cc you'd have to mill ~.021.
You can also do the reverse, say you want to mill a head .030 to figure out how many CC's that removes you take .030 / .007 = ~ 4.28. Milling a stock 5.7 head .030 puts your chamber at ~ 62.
02-16-2010, 01:23 PM
#6
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1218 = 1518
1518's are just nitrided and polished..among other things
They're rated .650 because the nitriding allows for higher stresses (on a spring, highest stresses are on the surface).
1518's are just nitrided and polished..among other things
They're rated .650 because the nitriding allows for higher stresses (on a spring, highest stresses are on the surface).
