Help with rocker problem.

VeeEight · Post by **VeeEight** » Wed Sep 24, 2008 5:16 pm

Hi Guys

This is a 351W stroked to 418.
I have had a rocker stud break on an AFR head (exhaust valve) causing the rocker (roller type) to come loose and rattle around the rocker cover. This has also bent the pushrod on the inlet valve, same piston. Do you think it is neccessary to take the head off to see if there is any damage to the valves or is it likely that the studs and pushrods can be replaced and all should be OK. Some help would be very useful.

Phil

ian.stewart · Post by **ian.stewart** » Wed Sep 24, 2008 5:53 pm

do a compression test, that will give you a clue if you have bent a valve,
More to the point why has the rocker stud broken, could be spring bind, could be valve float if you have ben using silly RPM allowing the valve to stay open and get clipped by the piston, stud pulling out, unlikely as they are airflows, I assume you are using a solid cam, what revs are you pulling, if you are roller hydraulic, they can over pump and keep the valve open, Solid lifter it could be the adjustment has come undone, and the pushrod pop out of the cup and bend,
The more I think about it, the more I would be tempted to lift the head, for the price of a gasket set, you could be looking for a new engine if the valve head drops off, or, do you know of anyone with a endoscope,

HairbearTE · Post by **HairbearTE** » Wed Sep 24, 2008 5:53 pm

I would certainly take the head off and have a look.

VeeEight · Post by **VeeEight** » Wed Sep 24, 2008 8:02 pm

Thanks Ian,

It is a solid cam and lifters. The engine has done 1500 miles from a complete build with all new parts except the block. It was dynoed up to 6000 rpm but I have not reved it above 5500 rpm during the 1500 miles.
Endoscope and compression test, good ideas.
Phil