Cam Sleeve Damage

[rgh0]

The root cause of cam follower sleeves moving in the castings is typically

1. A soft head casting so that the interference fit pressure is is lost overtime as thesoft heat metal distorts and creeps
2. Inadequate interference fit when a sleeve is replaced so the fit pressure is lost when the head heats up in normal operation


If the head is soft it will show the symptoms described above normally. But if it does not i would still get it hardness tested. If the head is adequately hard that would suggest an inadequate interreference fit for the failed sleeve and the risk then is what was the fit on the other sleeves and are they future potential failure points.

Steel cam followers would not normally cause a problem with the the sleeve moving. High lift cam follower are normally actually longer as high lift cams are ground on a smaller base circle and the follower stick out of the head more.

cheers
Rohan

[Phil Standing]

Thanks Rohan. Looking back in my records to 1974 (!) I see that I did get a sleeve renewed then and I have a feeling it was this one, did not note which one at the time. That might be the root cause - not enough interference when fitted. With the valve out I can see it will have to be an oversize replacement, just a question of how big. I'll get it hardness tested too.
Thanks.
Phil.