Originally Posted by shane.,herold
cobalt, the hex head on the stud is where i am having interference problems with the base of the rockers.
I dont remember the spring specs its been awhile, the cam specs are
Intake Duration at 050 inch Lift: 250
Exhaust Duration at 050 inch Lift: 260
Duration at 050 inch Lift: 250 int./260 exh.
Advertised Intake Duration: 283
Advertised Exhaust Duration: 290
Advertised Duration: 283 int./290 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.533 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.553 in.
Valve Lift with Factory Rocker Arm Ratio: 0.533 int./0.553 exh.
Lobe Separation (degrees): 106
What I neglected to say was the stud boss needs to be shorter. Sorry if this was confusing. That's what can happen when posting before the coffee has kicked in!
This is briefly mentioned in the link above (Valve train points to check). I need to go back and add the cures for the various conditions listed there.
These your rockers? http://www.summitracing.com/parts/cs...make/chevrolet
Hopefully you're using 7/16" studs (these rockers are also available for 3/8" studs), and as I mentioned above, GOOD (meaning stiff) pushrods. Stock wall thickness and diameter won't cut it.
A 1.65 ratio pushes the lift to 0.586" intake/0.608" exhaust. The piston to valve clearance needs to be verified, as well as the other things listed in the link above.