used cam and used lifters

[ol guy]

Cam lobes are ground flat, be it solid,hydraulic or roller. Lifters on a solid or hydraulic are convex at cam mating surface. This why lifters spin in the bores. This is also why roller cam set-ups want to screw in or out of a block requiring thrust plates and so on. Back to my original post on this subject, parts inspection is the key to whether or not it will fail. Also a clean lubricant without remnants of last failure still are still in the system adds a problem. If anyone has been around the rebuilding of engines business you learn real qwick what will and won't. As far as having the tools to measure convexity of a lifter, Sorry never needed one. I do repair and build motors not sell parts, although I have done both when needed.M

[Moneypitt]

Cam lobes are ground flat, be it solid,hydraulic or roller. Lifters on a solid or hydraulic are convex at cam mating surface. This why lifters spin in the bores. This is also why roller cam set-ups want to screw in or out of a block requiring thrust plates and so on. Back to my original post on this subject, parts inspection is the key to whether or not it will fail. Also a clean lubricant without remnants of last failure still are still in the system adds a problem. If anyone has been around the rebuilding of engines business you learn real qwick what will and won't. As far as having the tools to measure convexity of a lifter, Sorry never needed one. I do repair and build motors not sell parts, although I have done both when needed.M
Exactly, but as a cam wears it loses that flatness. The lifter and the cam wear together, and the lifter loses some of that convexity. Replace a happily worn lifter with a new one on a happily worn lobe and they don't like each other, from the very begining. Componant hardness is also a big factor. A miss matched rockwell either way will cause excessive wear. Granted, technology has come miles in recent years, but, to me, this is like switching around worn rod bearings on a new crank with different rods.......As I said, having to do a motorhome engine twice cured me...........MP

[hotrod56cars]

Thanks for the replies!

[Sleeper CP]

Got to help a fellow Cajon'er
Sleeper CP
Big Inch Ford Lover

[speedymopars]

Here is an article I found on the net talking about cams and Chevys
"Despite having gobs of horsepower and torque, the big block Chevy has one flaw that the GM engineers never fixed. It's notorious for chewing up new camshafts. Even with proper break-in procedures, experienced and professional engine builders have camshaft failures with flat lobes. This was actually the case with the first big block that was installed in project Rodent. The big block's poor oiling system and the angle at which the lifters are situated are the primary causes of this failure. Because of this, the camshaft doesn’t get enough oil and may fail at an early stage.
Fortunately, Bob Cherveny of B.C. Engineering figured out a way to correct this problem which GM should have taken care of years ago. It’s actually a quite simple design. A tube with several small holes is mounted above the camshaft and gives it a constant oil shower."
So, it IS a Chevy thing. :idea:
I will have to revise my thinking that you can put old lifters on a new cam in a Chevy. It sounds like you can't even put a new cam and new lifters in a chevy!
In a Mopar (and I assume Ford also judging from the comments above) you can do it. A quick browse of websites like Bigblockdart.com and moparts.com shows a lot of moparites have done this sucessfully (and the ones that failed did it to themselves by not doing a proper break in - IE, low rpm break-in, no assy lube, etc. basically the builders mistake).
The common comment why it works is that the lifter takes most of the wear and tear, not the cam, so a new lifter is a new wear surface that will be molded by the camshaft during break in.
Your mileage may vary - but it does explain why there are two camps.