OK, I need the combined wisdom of this august group. My TD (Charlie) has
started smoking blue smoke again. After a quick check of the engine,
including removing the air cleaner to ensure it was not being ingested that
way, I dropped one of the pistons from the bottom.
What I found could best be described as a thick substance that looks like
congealed oil on the TOP of the piston. It is very reminiscent of what I
found last year prior to a fairly complete rebuild, only this time it had
not been cooked to hard carbon. It was simply a very gooey oil layer about
1/8” thick. It did not cover the piston, but appeared in two overlapping
spots approximately under the valves.
What is strange is that very recently I needed to adjust the carburetors
because of a sticky throttle valve. It was only after this was completed did
the smoking start. It only starts smoking after the engine has run a while.
The warmer the engine, the more the smoke.
This past winter I had a number of things done:
1) The head was completely gone through (by a professional shop who
specialize in only cylinder heads), replacing the valves, guides, new Teflon
umbrella valve seals, and variable-rate valve springs - set to 70 lbs at the
valve seat. The head was surfaced and installed with a new head gasket.
2) A new (Crane) cam was installed, along with new tappets and push rods.
After these things were carried out, I found that I was burning oil, so I
then replaced pistons and rings. The bores we found not to be worn, but were
lightly honed to allow a cross-hatching for ring seating reasons. This cured
the oil burning completely - until this week, that is.
My questions are:
1) Why did this problem SUDDENLY show up after removing and replacing the
carburetors?
2) With all that was done to the head, could the oil be coming from there?
Or is there another source for the oil that I’m overlooking.
3) Any ideas as to a method of tracking down the leak?
Regards,
Lew Palmer
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