camshaft lubrication.....,discussion of theories.
 

While having the top end of an xt600 disassembled, inspection of the parts begins. Looking at the camshaft, it appears to be more "worn" on the journal closest to the cam gear than the other two journals. The cam shaft oil ports are all clear and the oil pressure is good. So, why does there seem to be a lubrication deficiency to this journal? Inspecting the head, the oil port comes up near the tach drive end of the cam. This "feed" "bearing" surface gets plenty of lubrication. The middle "bearing" surface has a significant "oil relief passage" machined down the center of it. Now onto the cam gear end bearing surface....it's machined groove is much smaller than the center one. Is this to create more oil pressure within the camshaft or is it for some other reason? This theory of lubrication passages carries over to the cam cover also. Why do the first two "bearing" surfaces have a machined oil pocket and the cam gear end has nothing? From what I can tell, this difference in lubrication design is directly related to what I'm seeing on my camshaft journals.

thanks for all of your feedback.