New engine start up question

[AVI_8]

Originally Posted by safe

Not directing this to you precisely, but what is really the logic behind limiting the rpms?

What is happening at 6000 that doesn't occur at 4000?

I see a reason for getting the engine up to temperature before getting the hammer down. I see a reason for doing pulls progressively up to higher and higher rpms to get a feel for the engine.
But I fail to see what damage that can occur going to redline in the first 10 miles, compared waiting 1000 miles.
I've given this some thought but haven't really found an answer, so on the few rebuilds I've done I have gone full tilt as soon as the engine is warm and has ok fueling.

Good question, I’m not an engine rebuilder for a living, in fact I haven’t worked as a mechanic for quite a while now , but I have rebuilt engines, its just what I was told was the “way” when I was an apprentice mechanic back in the 1980’s, my guess is that it may be to keep friction temperatures down at a time when friction may be at its highest, Its just what I would do unless someone who really knows what they are talking about tells me otherwise.

I would be interested in what views a professional engine builder has on this subject if Neil, Henry etc happens to read this.