Camshaft Oiling

[Ralgha]

I have my top end opened up for a valve adjustment (waiting on the shims) and the service manual says to apply molybdenum disulfide oil solution to the cam and journal surfaces when reinstalling them. None of the DIYs mention this, is it necessary or is that only for new camshafts? If necessary, does anyone have an example of the right type of oil to purchase?

[Flying]

Besides the fact that the service manual says so, It's a good idea to do so since you've been doing work in the head. This practice came about once it was discovered that camshafts have a break-in period. Not super necessary for regular service, but its cheap insurance against wear on startup.

It's just a 50/50 mix of engine oil and moly grease.

[Motofool]

Originally Posted by Ralgha

I have my top end opened up for a valve adjustment (waiting on the shims) and the service manual says to apply molybdenum disulfide oil solution to the cam and journal surfaces when reinstalling them. None of the DIYs mention this, is it necessary or is that only for new camshafts? If necessary, does anyone have an example of the right type of oil to purchase?

Oil remains inside the very small clearance fit between journals and bearings for a long time after the engine stops.
At start ups, the oil pump takes a time to feed those bearings, but the remaining oil film keeps the metal parts apart during those first seconds.

Your clean bearings are dry and will suffer some damage during the first start up, until fresh oil reaches the bearings.
That is the reason to pre-lubricate those surfaces prior to reassembly.

I use grease dissolved with oil, some use plain oil.
The molybdenum disulfide is just an anti-friction (hard to washout) additive for extra safety.

https://en.wikipedia.org/wiki/Molybdenum_disulfide

[Ralgha]

Makes sense, thanks. I'm assuming this would work, am I right? Permatex 81950 Ultra Slick Engine Assembly Lube, 4 oz. https://www.amazon.com/dp/B000HBNVSK..._QirWyb6ZVVHG2

[Flying]

That'll work fine!

[Ralgha]

Awesome, thanks for the help guys.

[CrazyCanuckGoat]

Save your money. Just put a couple drops of engine oil on the cam journals and call it a day. No need to overthink it.

This isn't a dry/freshly rebuilt flat tappet cam motor that has never been run.

[corksil]

Using molybdenum as an assembly lube while installing race cams fouled my clutch friction plates. I did use copious amounts, so perhaps that was the reason for clutch slip/failure.

If I had to go back and do the project a second time, I would have used lucas oil stabilizer in place of molybdenum for assembly lube.

The lucas product is petroleum based, and molybdenum is a slippery element if I'm understanding things correctly.