Originally Posted by jafroyd
I just put a new comp cams k-kit in my 327. I changed the oil and filter before break in. Is it absolutely necessary to change it immediately after break in? I've taken it out for a couple of road tests but nothing major.
The thing that sometimes happens is with filters where guys are not running the bypass valve, the break in paste can plug up the filter and if it's an un-bypassed continuous flow and it gets plugged, you're buying a new engine.
Aside from that, if the cam and lifters didn't fail during break in and dump a ton of metal shavings into the oil, there's no reason to immediately do an oil and filter change, the filter change being the more important of the two. At this point just to be sure you're getting rid of trapped moly and any shavings. You'll get some metal at break-in but it shouldn't be more than a very light metallic sheen floating on the oil.