I have been thinking lately about the cam break in procedure and why that it is recommended. You know putting the moly-lube on the lobes of the lifters, keeping the engine at a certain rpm range for a certain amount of time, using such and such motor oil for best break in, any special break in assembly lubes and so on. Why do we do this?

I work for an auto manufacturer and I have watched when they first start up the cars off of the assembly line and believe me they follow nothing like what the cam manufacturers recommend that you do when installing their new camshaft and lifters. No auto manufacturer, besides maybe hi-end ones, are going to spend 20-30 minutes to break in a cam, it is a matter of money. However, it is not uncommon these days to get an easy 200,000 to 300,000 miles out of an engine without any type of rebuild. So, why are things so different at the OEM's?

Don't get me wrong, I believe the break-in procedures are a very good idea. But, how much overkill is it really? Or is it more cya from the cam companies?

I would appreciate your all's response and explanations to my question.

Thanks in Advance,

Bart

Most manufacturers are using roller cams these days for one reason. Another that I can think of is the cams they are using as a lot smaller in lift and duration therefore the spring pressures are a lot lighter. The need for the extended cam break-in may not be needed for such small cams.
My .02

I agree with 67ss..........It's not like the OEMs never had cam failures. The move to rollers probably had several motivations. Elimination of cam failure, internal friction reduction and the reduction of wear particles in the oil are at least a few of them.

The lower lift and softer springs are valid points too. The whole point of increased RPM during the break-in period is to increase internal splash. This and the oil drain-back through the lifter valley are the only ways that the cam lobes are lubricated. Improved oils and filters may reduce the need for break-in slightly........but it's cheap insurance.

I read somewhere they spin crate motors over with air to break them in. Could they posibly also do this with new engines?

Chevrolet used to run new engines when they were assembled, long before they ever hit the assembly line. I don't know if they still do though?

I always wondered how much time the motor had on it when it left the factory. I never checked the hour meter when I bought my last Yukon.

I always wondered how much time the motor had on it when it left the factory. I never checked the hour meter when I bought my last Yukon.
You can count on your Yukon to have been driven to the restaurants at lunch break daily, with full load of workers