will changing brand of oil in a running engine [after a cam change only] do damage ?
engine in question has been running amsoil, and the change is to valvoline.
I run the engine for break in, how you break it in is a whole different subject, then change oil. More often than not to a different brand/type and no extra additives outside of anti-wear additives for a normal engine, usually none. i.e. break in with 30w conventional or break in oil and switch to 10w-40 synthetic at 500 miles.
Never had a problem.
Over the long haul I find it more important to change frequently and use a good brand. Clean oil is more important than the brand but the brand does have a definite effect over the long term. IMHO
