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Not enough information. Lifter type? Cam factory? This a simple cam swap situation or a rebuild? Assembly lube used? What oil? How is it being broken in? Is the system primed before fire up. How many miles to failure. See where this is going? 

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Engine only has 3k miles since build.First time had engine miss, tore down and found #7 intake lobe and lifter rounded. Checked head, springs, roller rockers, performance push rods, and lifter journal.  All looked good. Replaced cam with a slight performance cam and all new lifters. Used black paste on all lobes and lifter bottoms also used break in additives. #7 lobe and lifter rounded again before break in was done. Appeared all rockers were getting good oil. I'm lost.

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What I meant was did you roll the motor over by hand checking everything that can make contact. Not just does it have clearance but is it enough. Your cam manufacture will have minimums. Also as it is the same position did you check the spring pressures. Weak spring. Enough spring. You changed to a 'performance' cam. Matching springs? Clay the pistons? Is there something funky with that lifters bore? Oil feed or clearance? BTW, what oil are you breaking this motor in with? 


Yea, I'm fishing as I'm not there and can't see what you see and don't know this build or the builder.  






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3 minutes ago, Pete Kerns said:

All clearances look good. I'm still thinking oiling issue with that lifter bore. All springs are for the cam and were double checked at the machine shop after it happened the second time. Do the lifters get there oil from the hole inside the lifter bore?

Yep. The lobe however is mainly splash. 


Edited by Grumpy Bear
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