[john5670]

I took the motor apart yesterday because the motor was ticking. I measured the valves and the worst was .085, so I pulled the cam. This is what 4 lobes look like and the rest were getting there. Its not mis-matched parts.... everything was spec. by Butler and assembled by Wheeler Racing. What would cause this?

Take a look -

Comp x-energy

[Brian Baker]

I've never seen a cam wear like that...roller or otherwise. Defect in material or hardening process of the cam?

[screamingchief]

The lifter should'nt even be riding on that area of the lobe.

So my WAG would be they assembled the cam/gear/eccentric hardware improperly allowing too much fore-aft cam movement.

Seen many folks screw up that deal,even guys that know pontiacs pretty well.



Bret P.

[Brian Baker]

Originally Posted by screamingchief

The lifter should'nt even be riding on that area of the lobe.

Bret P.

Looks to me like the center of the lobe is deteriorated. What are you looking at that tells you the roller is contacting the lobe in the wrong area?

[screamingchief]

Originally Posted by Brian Baker

Looks to me like the center of the lobe is deteriorated. What are you looking at that tells you the roller is contacting the lobe in the wrong area?

From the poor pic quality I could hardly tell if it was a flat tappet cam or a roller,but a bit closer look shows some tracks on the other lobes.

I guess with a quick glance I thought it was a flat tappet cam.

Now we know otherwise...

Is the lobe damage on the opening or the closing side of the lobe?

If it's the closing side of the lobe I'd be checking the spring pressures closely.

What springs are being used on this ?

Seat & open pressures ??

What cam specs ???

What was the lash ?

Bret P.

[john5670]

This is what I think I have. When I find the paper work i will post the exact build.


Valve Springs: Pacaloy Springs 240 @ 1.900
Cam - Mild Comp X-energy
Rockers: Ultra Gold Pontiac 1.5 7/16 Aluminum Rocker Arms with Stud Girdles
Lifters: BPG Solid Roller Lifters
oil restrictors
Pushrods: Chromemoly
Heads - Butler E-heads ported to 330cfm (assembled by Butler w/Ferra race valves)
Intake - Rpm port matched

Dynoed:

586 hp @ 6000 Rpms
575 lbs of torque

[john5670]

The cam was installed properly. Its is a solid roller.....and the rollers still look like new. the tracking marks from the roller look consistent. The cam just fell apart it looks like. The motor was dyno tuned with the valve lash checked.

[bignate]

That has got to be a defect in material or hardening process.

[Brian Baker]

Agreed...the picture is blury.

[Brian Baker]

I still say it looks like a material defect or hardening defect of the cam. I've thought about it a bit and if it were a spring issue, I would think the wear pattern would look like, well...a wear pattern, and not a pattern that looks like a hillside when the soil erodes away. I would contact Butler and see what they think and see what kind of assistance you can get from them in dealing with the cam manufacturer.

[TCSGTO]

Looks like metal spalling which is a fatigue failure. Is the cam a cast or billet core?