Hello,

Gathering parts for a 460ci rebuild. This engine has approx 166K on it and was used as a heavy hauler in a 1985 F-250.

Should I take this opportunity to replace the cam bearings?

If so can anyone suggest a quality manufacturer?

Rgds

nonrev

 

If you are doing a rebuild then yes, that would include the cam bearings IMO. I had the machine shop do mine, I think we used Clevite.

 

Clevite are great bearings.

If you use a flat tappet cam make sure you ask the builder about the proper procedure for cam break in.
If he looks at you like your crazy or doesn't know then find another builder.
also make sure he checks that the lifters are free to float and spin without sticking.

I haven't heard about someone having a "Soft Cam Lobe " in a long time but I don't do many car engines any more.

 

Cam bearings don't survive the hot tank at most machine shops, so need to be replaced.

 

Yeah, if it's apart and has 166k I would do cam bearings. And if it's getting tanked you'll definitely need to do them.

Make sure you use a TON of assembly lube on the cam lobes and get a quality break in oil with enough zinc. A few years ago cams were failing left and right and it was because of two things. 1) Chinese lifters and 2) Oil being reformulated and zinc as well as some other things being removed. Zinc cushions the lifters but attacks the cat when the engine starts burning oil. Since new cars use roller lifters they got the oils reformulated to save the cats. The end result was that even if you did everything right you could still wipe your cam. I know a shop that wiped 2-3 cams in 30 years and they had 30+ in 2 years when all this started.

Once everything's broken in they seem to tolerate the new oils but for break in and the first couple of changes I would use an oil formulated for a flat tappet cam regardless of the cost because it's cheaper than a rebuild.

 

I add ZDDP to every oil change regardless of anything else.

I'll second the use of the correct assembly paste, I smeared it anywhere the cam touched.

 

The real cam problems a number of years ago were the Chevys, they would wipe a cam lobe off in nothing flat. We used to swear they used rubber camshafts. I put lots of the assembly lube on lobes, lifters etc. I use a 50-50 mixture of oil and STP on everything else when assembling my engines. I do not let someone else build mine, they won't always do it my way. I second the new cam bearings at 166K, you would be amazed at how much oil pressure loss you get from worn ones.

 

Yeah, the Chevy cams in the 60's and especially the 70's would wipe all the time. I've had a few of those cars and have a set of pushrod plugs so you can run the engine with the valve covers off and not get oil all over. That's the quickest and easiest way I know to see if the cam is wiped or not.

I'm referring to a few years ago when aftermarket cams were wiping out no matter what you did. The shop I was referring to has be around since the 60's in one form or another and they're setup plenty of cams so it wasn't installation or break-in that was the problem.