Where to degree my cam?
Steve, it would be installed @ 102 to achieve 4 deg advance. 102 meaning the degree after after true tdc that the intake valve is on its peak opening. Its "centerline" of the lobe. So If they want it at 106, 102 would be advanced and 110 is retarded. Changing the icl also changes the intake and exhaust valve open/close in the same way.
This is why it is really important to discuss with the person you are advising what
you mean by advanced. Because if you have a 110 LSA, to me a 110 ICL would be straight up. 106 ICL is 4 degrees advance 102 ICL is 8 degrees advanced and 112 ICL is 2 degrees retarded.
On a 110 LSA, if everything is perfect, i.e. crankshaft keyway, cam and crank gears, camshaft pin, and you install the timing set dot-to-dot and the ICL comes out to 106, you have a camshaft that is ground 4 degrees advanced.
The 20-309-4 is a cam that is
supposed to be ground with 4 degrees of advance in it. It should come out that way (106 ICL) when installed dot-to-dot. But to know for certain that everything is correct, the camshaft should be timed.
The above description doesn't mean that anyone who see's camshaft advance/retard differently is wrong. It only means, this is how I describe it. So if you are talking to a camshaft company or another person, get your definition straight before hand, so you understand each other.
