Oil Fouling

I would like to know what is the most likely cause. If I have to pull the head, I desire to have a plan in place for valves, rings, cylinder, etc. There are not any shops that I know locally that have experience with these engines.

If you decide a ring job, valve job, or rebuild is in your future, actually nearly everything can be done without pulling the engine, and with common hand tools, and a manual. You may find that you don't need a machine shop that is experienced with these engines.

George

They do make plugs with an internal gap to raise the voltage for oil burning engines, some abomination made by Champion for old engines that seem to have short life. Avoid Champion plugs, they foul in good engines and don't respond to cleaning.

They also make a plug extender that moves the plug out from the combustion chamber to reduce the oil that hits the plugs. Probably only to be found a J.C. Whitney, not your local auto parts store.

Gerald J.

The other possibility is that the valve guide is worn and/or the intake valve seal is damaged or worn. In this case, the exhaust would be the smokiest when the the intake manifold vacuum was the highest, i.e at idle and low power. Your post says that it's smokey at high power so I'd guess that the former is your problem.

Smoke under load at the higher rpm's is most likely due to worn rings but it can also occur with bad oil control rings which are designed to scrape some of the oil film off the cylinder. it can also occur with really worn valve guides that shouldn't be your problem since you have the head redone. You can try MMO and see if it works. I tried it on my original engine and it didn't work for me but that engine was plum wore out. To see how worn your rings are run a good compression tst (Engine at operating temperature, all plugs out, throttle plate wide open and air cleaner tube disconnected at the carb inlet.) That will give you an idea if the engine is needing rings. The anti foulers you are using are just a way to get a few more hours out of the engine to postpone the inevitable. the white smoke out of the brether is mostlikely water vapor and that should go away after a few hours of high temperature operation. If it doesn't, you may be getting coolant in your oil and you'll need to figure out where that is coming from. Any signs of water in your oil?

I think your machine shop is wrong on the valve stem seals. The TO 20/30 have neoprene seals on the intake valve stems, but none on the exhaust. The intake is where you need the seals to slow down oil being draw into the pistons. Another typical indicator of worn intake seals/guides is an oil burning cloud at start-up that decreases after a few minutes of run time.
Dan, it sounds as though your TO oil burning is probably piston rings, either worn or broken. Your engine sounds like mine before I rebuilt it. You can replace the piston rings, pistons, sleeves, etc. with the engine in place on your TO.... if you were so inclined. When I went to replace the rings (just the rings) in my TO.... I ended up doing a total rebuild... I couldn't seem to stop myself. Gotta watch that "mission creep".

George

George