Reply to "MME ENGINE FAILURE UPDATE"

What are the lift specs on the camshaft?

There are only a few ways to snap the rocker arm like that in my view.

Either the rocker arm, on the valve side was bottoming out against the rocker arm pedestals (unlikely), you have very high rate valve springs AND the valve spring retainer was bottoming out on the top of the valve guide ((pretty high likeliness) OR you have valve spring bind because of a mismatch with the lift requirements of the camshaft.

The assembled height of the valve springs may also be incorrect. That would make the rocker arm go past center of the valve stem and COULD cause a binding.

These problems all stem from high valve lifts and the fact that if they did happen, none of those clearances were checked by the builder.

Did you decide initially on one camshaft lift spec, say .585", and then at the last minute increase it to over .600"?

Also remember that if you chose a hydraulic lifter camshaft, normally you never get 100% of that lift. If the clearances were checked while the engine was not runnig and the lifters were not pumped up, it is likely to get a false reading of something like .100" too low.

The percentage of lift attained with a hydraulic lifter is going to depende on how much oil pressure they get at running.

It is possible that in the break in period you lost some of the tension in the springs allowing more lift and causing bottoming out that was never seen on the engine stand.

Unless God said it was OK, NEVER run an hydraulic lifter in a performance engine.