Occasional Smoke on Startup

[miguel]

I have a recently rebuilt 345 in my 79 Scout. The engine has about 30 hrs on it. The engine starts easily and runs smoothly and strong. Occasionally, when started about 15 minutes after a short drive, it will start with a cloud of blue smoke that would make a r-2800 proud. Normally, there is no blue smoke for starting under any conditions and it does not seem to be burning oil.

What could be causing this?

 

[Robert Kenney]

Fairly normal for an older designed engine with only oring valve seals. I'd ignore it.

Or you could install umbrella seals. I don't recommend running the pc/modern seal as they are excessively restrictive. A hard working engine will require more stem/guide lubrication and can suffer valve sticking if under lubed.