[70bird]

I have a Gen 5 HO 502cu crate engine in my '70 Firebird. It has just over 3000 mile on it and the distributor gear is sharp enough to slice your finger if you run it across it. The wear is uniform. It looks pretty even the whole length of the gear. I don't have a roller cam, so that's not the problem.

Any Ideas?

[87442lover]

Why would a roller cam have anything to do with it? Roller cams are less stressful on the engine.

Wheres that page with wear patterns?

[willys36@aol.com]

http://hotrodders.com/showthread.php...ar+lubrication

http://hotrodders.com/showthread.php...ar+lubrication

http://hotrodders.com/showthread.php...utor+gear+wear

http://hotrodders.com/showthread.php...utor+gear+wear

[johnsongrass1]

Incorrect spacing of the distributor gear often causes wear. If the heads, block or manifold were milled excessively the dist. height would be affected. You may need to place shims between the dist. and manifold.

[70bird]

I've read that roller cams are made from billet and are made from harder material than a non-roller cam. The harder material will wear down the softer distributor gear. I think it was in Car Craft about 5 or 6 months ago. They did a walk through on going to a roller cam in a non roller engine.

[willys36@aol.com]

Originally posted by 70bird
I've read that roller cams are made from billet and are made from harder material than a non-roller cam. The harder material will wear down the softer distributor gear. I think it was in Car Craft about 5 or 6 months ago. They did a walk through on going to a roller cam in a non roller engine.

As usual, the car magazine got the facts 100% wrong. It has been decades since you could trust anything a car mag says, basically since the likes of Roger Huntington retired. Hardness of the drive gear has so little to do with wear on the driven gear it isn't worth discussing. As long as the gear isn't too soft, which is not very likely, the only critical specifications are geometry (precisely correct in the vast majority of cases) and tooth surface finish. If the teeth on your cam gear are smooth and shiny, your problem resides in lack of lube, over-stress on the driven gear from too big a load, worn bushings, or some other cause on the driven end.

[Shawnski]

I had the choice of brass or hardened steel for my roller cam. If it is a race motor and is tore down often, go brass very forgiving on the mesh, however street engines demand the steel gear for longevity as the brass lasts oh about 3000 miles...