Thread: 383 Broken rocker, stud, pushrod

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i have a 383 stroker 9.5:1 pistons cam is .480/.480- 230/230- 107 spec it has 76cc cast heads, comp springs .530 lift and 2.0 valves. the problem is i got the motor running dialed the timing in and drove it. 100 miles later #6 cylinder broke the exhuast rocker and bent the intake push rod. it has stock rockers. i put a new rocker and pushrod on and it was fine until another 100 miles #8 cyclinder broke exhaust stud and broke pushrod on intake valve. the builder of the motor says it is getting to hot in the cumbustion chamber and causing the valves to stick. both times it broke it was not running hard at all. i was told roller rockers will solve the problem. any suggestions of whats causing this?

stock rockers wont work right with that much lift-go with roller rockers

Get your money back.

sounds like they left the valve guides to tight. been there done that.

Originally posted by 78stroker
i have a 383 stroker 9.5:1 pistons cam is .480/.480- 230/230- 107 spec it has 76cc cast heads, comp springs .530 lift and 2.0 valves. the problem is i got the motor running dialed the timing in and drove it. 100 miles later #6 cylinder broke the exhuast rocker and bent the intake push rod. it has stock rockers. i put a new rocker and pushrod on and it was fine until another 100 miles #8 cyclinder broke exhaust stud and broke pushrod on intake valve. the builder of the motor says it is getting to hot in the cumbustion chamber and causing the valves to stick. both times it broke it was not running hard at all. i was told roller rockers will solve the problem. any suggestions of whats causing this?

Tear,it down and have them hone the valve guides.Also check your valvetrain geometry.

grab one of the retainers and see if you can move it by hand if so it may not be the guides. some of the stamp rocker and cheap roller rocker geomerty sucks and some of the steel stamp rockers are junk to