Cam Bearings

[Robbie693]

Looks like I'm going to need a new set of bearings for the cams, some have grooves in then and raised bits/lumps..

Are they just fit and put back together or is there more to it than that?

Hopefully

Robbie

[CBUEB1771]

Robbie,
The new bearings should fit up well with attention paid to cleanliness at assembly. The narrow set are for the last cam journals at the back of the head. Make sure that the oil feed drillings at the front journals are not masked by the bearing shells. Has anyone cleaned your cylinder head by glass beading or other abrasive blasting? That is a common cause of grooves being cut into the bearing shells and bearing journals. You can try all you like to wash the blast media out of the head but it is usually the oil pump that provides the last cleaning with unfortunate results. Could you post a photo of these raised bits/lumps?

[Robbie693]

Hi Russ, sorry for the delay.

I have no evidence of any blast cleaning being done - I have receipts for head work in 1988 but no mention of cleaning.

The car has done less than 10,000 miles since the rebuild but I think it may have stood for some time without use. I was wondering if corrosion could have caused the pitting in the bearings..

I have found a few bits of aluminium swarf which look like they have come from the cam cap dowel holes (found some loose bits here) and there were a few burrs and scrapes in the caps themselves, which I have cleaned up.

The cams themselves look ok, apart from some brown staining in some areas which looks like rust but is smooth so I don'tt know what that is (see pic)

I bought new bearings and fitted them yesterday, using graphogen for lubrication, and the cams turn fine.

Pics of old bearings: