COMP-Cams quality.........

[olddog]

I haven't the experience of a professional builder and wouldn't make a pimple on Barry's butt. That said I only speak to learn more, as it is an interest to me.

The overhead cam engines I have had apart used cam followers. Many may be rollers, but some are not. Specifically they were the 2.2 Chrysler, and a 95 Ford 4.6 4v. The followers rub against the cam lobe. There was no roller tip. I believe the 2v modulars were a similar design. I don't know the geometry to understand if the ratio is similar to a rocker arm set up. So the loads could be way different, but the design would have some things in common with a flat tappet lifter, as far a a flat part rubbing directly on the lobe.

In the Ford modular case, the lobes are made from powdered metal that is harder than the hubs of hell. Then the individual lobes are slid onto a hollow shaft. The shaft is expanded to grip the lobes and a cam shaft is made. A very different process, to make a cam. Lobes will crack, but not wear.

I saw an engine that was assembled without the intermediate shaft between the oil pump and distributer. (Red neck mistake, it was not primed with a drill) It ran for a good 5 minutes before, the zero oil pressure was believed (didn't think the electric gauge was correct). When the lifters started to tap, a mechanical gauge was installed and it was restarted. It ran on the assembly lube only. No splash oiling; no oil being pumped. The intermediate shaft was installed. No damage to the engine. It lived a long life. It was a mild after market cam with normal springs and rockers in place. The point being that you could not have broke a cam in more wrong, and there was no problem. Then a guy like you meticulously does everything right and a cam wipes a lobe.

I cannot help but think that all the cam break in procedures is a magicians trick to keep our eyes focussed on something other than the real problem. I'm not saying that they do not help reduce failures. They might, but that is beside the point. If it does matter, it is because the design is on the ragged edge of failure. It sure does give the cam manufacturer a bunch of cover to claim you didn't break it in correctly.

I have never understood what needs to wear on a cam break in and how that wear is supposed to stop. I understand that a cylinder is honed and the rings will wear it to get a perfect fit/seal. Why would I want a cam and lifter to wear together to get a perfect fit?