I've got a GM 2.8l 60 degree V6 out of an 1988 Cavlier. Its got about 320k kilometers (200k miles) on it. When I pulled the cam out I noticed that some of the lobes were worn round. I have not measured each lobe but by visiual inspection it appears that there may be a pattern. The lobes are worn most on the timing chain side - moving away from the timing chain side the wear decreases, until at the other end there is no wear.
My first thought was worn cam bushings at the timing chain end doing something weird to the cam, but I couldn't figure out how that would cause this type of wear since the cams simply work against the lifters. Then I thought perhaps there is something in the way the oil flows in these engines that may lead to more wear at the timing chain end over time.
Another reason might have been a coolant leak at this end of the enigine with coolant getting on the worn lobes ???
Any ideas ?
As a side question, can anyone recommend a good modern source of info for using gaskets and sealers when I rebuild ?
Thanks, Bep