I'll_SHO_U
New Member
I'm in the process of doing the upper 60k and have noticed on some of the cam lobes theres some dark spots. What would cause this and more importantly, should I be worried? Thanks
cam stains
- Thread starter I'll_SHO_U
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
Yamaha V6
SHO Enthusiast
whoa boy, I could have had a LOT of fun with THAT topic description...
Are the stains actually pits?
Are the stains actually pits?
Mels
SHOVELHEAD
Hee hee, "Cam Stains" sounds like an old David Allen Coe song...
sdpatt
Sr. SHO Engr.
Carefully addressing this issue...
Where on the camshaft lobes are the spots? Are they on the heel side of the lobe that doesn't touch the shim? If so, it is only metallurgical corrosion (oxidation) and not a real concern. If the spots are on the ramp faces of the cam lobe that contact the shims, then there may be more severe corrosion or lubrication issues. Without seeing them, it is really only a guessing game.
Where on the camshaft lobes are the spots? Are they on the heel side of the lobe that doesn't touch the shim? If so, it is only metallurgical corrosion (oxidation) and not a real concern. If the spots are on the ramp faces of the cam lobe that contact the shims, then there may be more severe corrosion or lubrication issues. Without seeing them, it is really only a guessing game.
AutoSHO
No SHO = Mo $$$
sdpatt
Sr. SHO Engr.
Example of corrosion on cam lobe heel. This finish was not in evidence on the ramps.
AutoSHO
No SHO = Mo $$$
eek! Those look horrible!
I'll_SHO_U
New Member
The stains are on the ramps that contact the shim but not nearly as severe as the picture scott put up. I really shoulda documented the lobes that had the stains on them but I guess its a little late since its all buttoned up. So whats the long term senario with this?
<small>[ October 02, 2003, 03:18 AM: Message edited by: I'll_SHO_U ]</small>
<small>[ October 02, 2003, 03:18 AM: Message edited by: I'll_SHO_U ]</small>
sdpatt
Sr. SHO Engr.
If it was staining like the coloration of the engine internals from the oil being used then there may be no effects whatsoever. If the staining is a corrosion or oxidation that causes a roughness on the surface of the pressure face of the cam lobe, then there will be more rapid wear of the shims and eventually the cam lobes. You may want to consider performing the next valve gap adjustment at less than the recommended 60,000 mile interval.
Similar threads
