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Old 09-04-2010, 01:06 PM
dlotz dlotz is offline
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Location: Kalamazoo, mi
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Quote:
Originally Posted by Excaliber View Post
No problems with my flat tappet Comp Cam I put in several years ago. I did take extraordinary measures to break it in. As I recall the first 20 minutes after the first start up determine whether a flat tappet cam will live or die, you usually find out in the near future following that.

I'm wondering what steps were taken during the dyno break in to assure a long life? Removal of the inner springs? Break in rocker arms? Holding the rpm at or above 2,000 rpm for those first 20 minutes? If it went straight to the dyno without any special mechanical attention to break in, there's the problem! For an engine builder, doing any of the above is a real pita, it takes up a lot of time and eats directly into the profit margin. That is why so many builders won't even offer a flat tappet anymore, just to much hassle and risk if you don't get it right.

Hotfingers, roller lifters don't generally require any special mechanical attention for break in. Wierd you had a run of bad luck, I don't know what to make of it. Some years ago ALL the cam manufacturers were having problems with flat tappets, which was eventually traced, primarily, to the changes in oil available. That remains an issue, but of far less concern with the roller lifters, then or now,,, strange. Another factor, then and it remains an issue, is low quality lifters, perhaps made in China sort of thing. A large number of cam failures, some years ago, were a direct result of readily available cheap and inferior lifters.

Barry did everything to correctly break in the cam at the dyno, I was there. We used the BP break in oil and additive, we had the inner springs off, warmed it up for a good 30 minutes. Then we shut down, added the inner springs, checked/adjusted the valve lash and started again checked timing, adjusted carbs and then stated the pulls. Barry has been doing this for years and knows his stuff.

Funny thing is that the paperwork that came from the cam has a disclaimer blaming oil for flat tappet cams breaking. I sure hope this wasn't an old cam they just pulled off the shelf somewhere that was from that era. The lifters and cam came as a set so if either are junk then they are both CompCam parts.... and still under warranty!

We checked the rocker and adjuster and they are NOT loose which tells me the slop is on the cam side. Could it be anything else I can check before we pull the engine?

I am still under warranty, but as mentioned the time and labor is the pain. Especially when we were supposed to unveil it at the family reunion tomorrow! Like they say, it happens

Last edited by dlotz; 09-04-2010 at 03:52 PM..
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