Need help figuring DCR for LQ9 with FM11
Need help figuring DCR for LQ9 with FM11 Need help figuring out the dynamic compression on a modified LQ9. This is for a motor going in on '01 Firebird. The heads are off and are going to be getting decked, but I don't know how much dish a LQ9 piston has nor do I know the .005" duration for Futral's cams.
Ben T.
Ben T.
I can do the calculations myself I just don't have all the variables.
It's a 114LSA FM11 installed dot-to-dot. Compressed gasket thickness is 0.042. We'll assume the pistons are 0.007 out of the hole.
Thanks for the help Predator-Z. I'd like to have the advertised duration and the amount of dish that a LQ9 piston has so I can play around with it.
Ben T.
It's a 114LSA FM11 installed dot-to-dot. Compressed gasket thickness is 0.042. We'll assume the pistons are 0.007 out of the hole.
Thanks for the help Predator-Z. I'd like to have the advertised duration and the amount of dish that a LQ9 piston has so I can play around with it.
Ben T.
Okay, it looks like people use the rule of thumb .050" duration plus 50* equals duration at .005" degrees of lift. That makes the 228 lobe climb to 278* of advertised duration. Using those figures I'm coming up with;
A 67.x cc chamber yielding around 10.9+/1 compression and 8.4x/1 dynamic with around a .020" mill and using a .042" head gasket.
This sound good to anyone else? I'm pretty sure it'll clear, how does clearance sound to other people? .042 gasket, .020" mill and a 228 intake lobe on a 114LSA +4.
Ben T.
A 67.x cc chamber yielding around 10.9+/1 compression and 8.4x/1 dynamic with around a .020" mill and using a .042" head gasket.
This sound good to anyone else? I'm pretty sure it'll clear, how does clearance sound to other people? .042 gasket, .020" mill and a 228 intake lobe on a 114LSA +4.
Ben T.
The tigher LSA (or more advance) would both further limit the amount of clearance, but if you're going to be running a stock head gasket and, say, a .025" mill it should still clear and yield a DCR in the 8.2ish range- which still isn't bad.
Ben T.
Ben T.
