Cam comparison

dukeboy_318 said

So I’m mostly worried about the flat tappet issue that seems to be plaguing the industry right now. Since 2020, out of the 23 in our car club, 19 have had their flat tappets wipe. And some of these guys have been been hot rods since the 50s.

The last one that just had his wipe was in an engine built for his drag car by a professional Indy car team in Speedway. Last 14 miles after breaking in on the dyno. Hydraulic lifter failed

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So was I, ESPECIALLY after losing 9 or more lobes very recently on an engine break in I did on a Chevy 402........and I did everything right. First time I have EVER flattened a cam on an engine since I've been working on cars. Yes , it was a Comp Thumpr hydraulic flat tappet.

That said, I was really nervous when I recently finished the engine swap on my 75 F250, Gladys. I've had the 400 for her built and stashed for a few years. Did everything right there. Initial fire up went fine. After it got good and up to operating temp, I could hear the lifters ticking. I was sweating bullets. I put probably 200 miles on it and it got no worse but got no better.

I changed the preload several different ways. Although the rockers are non adjustable, the rocker pivots can be shimmed to change preload. I tried light preload, medium, and heavy. No change. This was with expensive Crower Cam Saver lifters.

I said screw it and tore back into it and replaced those high dollar lifters with stock Melling $4.99 a piece lifters from Summit. Broke it back in and it's been quiet as a MOUSE and running great ever since. Talk about dodging a bullet. The Crower lifters looked great as for breakin wear, so the ticking was in the valving of the lifters themselves. So I cannot recommend the Crowers.