Inliners International Forums General Discussion Hi Performance My '78 250 cid build

I've been playing around with these numbers for awhile now trying to convert them into proper valve timing on the camshaft, but so far they make no sense? The intake valve should start to open before TDC, but I observed it 30 degrees of flywheel (or about 15 degrees of cam) after TDC. The same thing is true of the exhaust closing which was 20 degrees of flywheel (10 degrees of cam) before TDC instead of after. Now there is probably some degree of exhaust closing and intake opening between those points that I can't see with my bare eye but probably would show up on a dial caliper, and that should be added on. And maybe the slow turning of the crankshaft is causing the hydraulic lifters to absorb some of the lift on the opening and closing, restricting the opening and closing I can observe. I'm not sure how many degrees to add to the timing of each event to get the proper cam timing numbers?

Also I mentioned above that I hooked up my compression gauge to each cylinder, and they all delivered between 180 and 190 psi on multiple turn overs each. My concern with swapping to a non-integrated head is the thick .040" replacement head gasket that is the only commonly available option. Without a lot of chamber reduction from decking, and/or advancing the stock cam, the cylinder pressure is going to really drop.