Reply to "Normal engine life"

The internals that wear the fastest are the valve guides and the rocker arm tips.

That is because of the scuffing action across the top of the valve that the rocker arm has.

Some engines will show noticeable oil consumption as a result at about 60,000 miles. Some less.



IF you install a set of roller rocker arms then the thing could go on forever seemingly without needing a rebuild.

Difficult to say if it's better for mileage to use the original cast iron piston rings or chrome molly ones?

It's usually the block wall that shows the wear from the friction though.

Full synthetics will reduce that wear if used after break in.



My engine builder will tell you that the rings are seated within 5 minutes of the initial start up.

I did have a 427 Ford with chrome molly rings that ran like crap for a lot more than 5 minutes after start up. We were looking at what was wrong with it internally and all it was, was the rings needing seating.

Top and bottom were molly. That might have been a mistake AND it was running with open breathers.



The bottom ring HAS TO HAVE 12 in-mg of vacuum in the crankcase to seat right. You don't get that with open breathes. In fact there may be a + pressure wise which is just not good.