Comp cams xe268h for 318

dartfreak75 said
Here is some more brainstorming if you do the math 3.31/2=1.655 + 6.123 for the rods - 9.6 for the deck that puts us at 1.822 (max compression height at top of the block) so if I am .1 under the block then that leaves us a piston height of 1.722. The largest c h piston i can find in the cheap range (ie speed pro etc) is 1.755 with no eyebrows. That will put me at 8.78 then if I could mill my heads a little let's say .020 that that will put me at 9.18. That Is about where I want to be. That is still gonna run me about 140 for the pistons plus machine shop labor for getting the pins pressed and heads milled. But this would be a better bottom end. If the bores are good and not wore

There ya go... that's how it's done. With those numbers above, I get 8.6 SCR with a 1.755 CH (.067" below deck) and no eyebrows but adding 1 cc for the gap down to the rings, a .028" thick head gasket. So that is close to your 8.78 number.

For milling the smaller area of the 302 chamber means you will have to mill something like .007" for each cc taken off of the volume. So milling .020" would get about 3 cc's off and if the chamber start at 65 cc's then that 62 cc result would get you to about 8.9 for SCR. Getting better. I'd go at least .030" and also measure those head chamber volumes carefully, they may be smaller than you think. If you get the chamber down to an actual 60 cc's then you get to 9.1 per my numbers, again, using the .028" thick head gasket.

With that, you are at around 7.3 for DCR IF you advance the cam timing to an ICL of 104. That is a ton better than where things were heading before.