I don’t recall the original cam going flat.
Am I remembering that right?
No mention of the installed height on the springs.
The Comp 911 is a fairly stiff single spring.
(If installed at the factory height of 1.860, the load would be 137 closed/
[email protected] lift. While many people have broken cams in successfully like that, I think you’d find if you called around to some cam grinders that they preferred the open load for break in to be like 275 or less.)
If you used a zinc additive in regular oil, that’s not even close to the same thing as actual break in oil.
I always use a paste/or grease style of cam lube...... I have no idea about what comes with a Summit cam.
No mention of whether or not you verified lifter rotation.
One of the pics you posted of the old lifters had one that was clearly not turning.
That would have been the first thing I checked with the new cam & lifters.
If you used Summit lifters, they are usually imported. Should show country of origin on the box.
Might not matter...... then again, it might.
And, we don’t know what the lobe taper situation is.
I’m not hating on the OP, but it sounds like there might be at least a couple items that could be “improved” on for a higher success rate of cam break in.
Sometimes **** still happens.
Recently I was talking with a customer who was interested in getting a cam to replace one that didn’t make it thru break in.
We discussed all the things he had done in preparation for the break in, and it really sounded like he had all the bases covered...... and it still didn’t survive.