Solid rollers with off set push rod hole issue.

gg408 said

Thank you all for the replies.
The damage on the lifter is on the opening side of the ramp just before the top. The lifter bores where bushed for flat tappet solid lifers that measured .904"and these BAM lifters measure .903", so the clearance is about .0028" atm with the BAM's.
Spring pressure are 255 lbs on seat and 560lbs over the nose.
Cam specs are 255/262 deg @ .050", 112 lobe sep, lobe lift .399'intake .409'exhaust with 1.5 rockers.
All intake lobes have same wear pattern , runs on one side lobe , runs flat across the top then runs on the opposite side of the lobe going down. its as if its trying to turn twist the lifter.
This has me stumped

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I would venture that the 0.0028"lifter clearance with the offset lifters is causing the lifter to tip in the bore. This will put extreme load on the contact area of the lifter roller and cam lobe on the opening ramp. The spauling is metal fatigue from the extreme contact point pounds (tons) of force. Properly set up with full width roller contact across the cam lobe, you have the spring load multiplied by the rocker ratio and then the acceleration or inertial load along a fine line of contact. Now it the lifter has a bit excess clearance and some force can push the lifter offset in the bore or the bore is not 100% perpendicular, the load contact is reduced from a 3/8" line to a 1/32" or 1/64 contact point. If we consider the 1/64" point width, the loading is 24× what it should be. Metal will fatigue very quickly in that circumstance.
I would get the block inspected very carefully. You may need to rebush the lifter bores with a tighter tollerance and go to centered lifters.