Rebuilding blacktop head

[JT]

Standard blacktop dropped an exhaust valve. The keeper notch has worn off and let the valve drop down. Known issue or unfortunate? Is it worth replacing all the exhaust valve keepers?

Pulled the head off. Everything else is in good condition.

Who does the best deal on gasket sets for a head?

[touge_ae101]

have had one of the keeper rings come dislodged from a shim that fell off the top of the valve and was resting on one side of the retainer. yours could have been something similar. luckily i checked mine within 2mins of running and didn't cause any problem.

if they all look like that are in the groove properly etc i would say leave them. haven't heard of it being a common problem.

[matt dunn]

Have heard of it happening and I have also almost had it happen to me.

When you lift the cams the buckets come up slightly,
the shim sticks to the inside of the bucket,
then the shim drops off and falls to one side so it is resting on the keeper,
and the the bucket drops back down.

None of this you can see and the only way to tell if it has happened it to recheck valve clearances.

As the shim is now resting on the keeper it is only time till it drops a valve.

Had it been apart recently?