V7 Engine Rebuild—What oil to use?

[Stretch]

https://www.thisoldtractor.com/moto_guzzi_loopframe_engine_break_in___initial_start_after_rebuild.html

From the above link on another thread going on this forum:

I've never used break in oil. Just regular oil - usually 15/40 diesel oil (Rotella) or 10/40 of just about any manufacture. I don't use synthetic oil - almost all ring manufactures tell you not to. This isn't an issue for the factory (newer bikes or cars that come with synthetics) because they belt the hell out of motors before delivery on "break in oil" and then refill with synthetic.

So that's why new cars come with synthetic and don't need a "break-in oil change?"
Never knew that.....

                                                          -Stretch

[jacksonracingcomau]

A sticky breather valve, a clogged passage etc.

But that wasn't actually my point. As you know crankcase pressure is created by the well sealed pistons moving in the cylinders and case.

On modern smallblocks it seems to push a lot of oil into the airbox through the breather system.

Therefore consumption is sometimes from drawing it into the throttle body and introducing it to the combustion chamber that way even though the rings are fine.

That was the point.

Are you suggesting a design fault.?
I think not , lots of happy customers

My “old” SB, 8v 650, jerry rigged breather, sort of same
Zero anything in catch tank
If I overfilled it, who knows?