Camshaft failure

[Alan Roehrich]

Originally Posted by Michael Pliska

A couple of questions:

1) Is the zinc and single-weight oil necessary for break-in with a roller cam BBC? Using Total Seal gapless second rings.

2) Is an additive necessary for an already-broken-in hydraulic flat-tappet SBC?

For both these engines, I plan on using (at least until I run out of it) older Castrol GTX 20W-50. I've had a few cases of the oil around since I used to run both cars back in the early 90's. I've already been using it in engine #2 since I put in new rings and bearings (just reused the camshaft and put the lifters and pushrods in the same locations).

Regards,

Roller camshafts don't break in. But a good mineral base oil is really necessary for initial ring seating in most cases. No comment of the gapless second ring (and yeah, I run Total Seal, just no gapless rings at all, ever).

I suppose a certain amount of ZDDP is necessary, in most cases with flat tappet cams, although I also think some synthetic oils have a good enough extreme pressure package that they work without ZDDP.