camshaft failure

[OneStopRestoration]

SpeedyB

Its pretty quiet, however the exhaust note is on par. For a little more money you could go solid rollers, to get back lifter tick. I considered that but deicded the hyd roller was my route from now on.

[Crossbreed383]

Good morning everyone..
Please re-read post #14
I tried to politely give the reason without throwing any companies under the bus, but
hey, looks like multiple people in here have seen the same from said company.
It is a core issue, plain and simple .
Thanks

[RobR]

Thanks Pete!
Nick’s post:

Originally Posted by Crossbreed383

The issue IMO is more to do with insufficient case hardened depth on the cam cores being used. The issue is when the case depth on the nose isn't enough and this is magnified because of spring psi being highest at over the nose of the cam, than on the base circle of the cam .
Certain companies use the same UGL( unground lobe ) cam cores for a multitude of cam valve events, pt numbers , etc . The issue lies in that you harden the lobes during heat treat, but when you try to cut the more than one cam profile, using multiple centerlines or lobe lift( base circle) on the same core ,you end up grinding away too much or even going through the heat treat in some spots.
If the use a specialty UGL for each specific cam then the case depth is set at XX mm of what it needs and you after final grinding you are left with sufficient heat treat depth.
We see it all the time here .
Thanks

[big gear head]

I'm building a 327 for my dad's 55 Chevy. I'm using a Comp Cams flat tappet hydraulic cam CS XE284H-10. I took it out of the box and was cleaning it to get it installed and I noticed that the lobes had a rough finish. I put it in my lathe and turned it slow while running a wire brush over the lobes. I used gray ScotchBrite after the brush and the lobes are smooth. I wonder if this has anything to do with the failures. Pictures are before and after. It's hard to tell in the pictures how rough the finish was before cleaning them.

[Too Many Projects]

Before pic looks like 100 grit sand paper. Looks a lot better after, but are you going to trust it, Freddie ?? Was the rough texture case hardening scale ? Seems it couldn't have been machining burrs if it came off with a wire brush.

[big gear head]

We are using the new diamond coated lifters on it, so I feel pretty good about it. I have no idea what the junk was that was on the lobes. It wouldn't come off in my mineral spirits tank. The wire brush took most of it off pretty easy. I heat treat metal all the time, and I'm pretty sure that this wasn't scale from heat treating it.