In article .com,
"Denny" wrote:

Just a follow up... The waters are getting murky...
Flew the plane to my mechanic... This gave us a hot engine for an
immediate compression check on the suspect cylinder.. 73/80...
No out of round cylinder here and no audible blow by in either the
exhaust or crankcase... hmmm...
Could be a broken oil ring but the replacement spark plug I put in
after finding the oil fouled plug, is clean and dry and firing just
fine after 3.5 hours of flight time... hmmm...
A check of the other 3 bottom plugs reveals them to be free of oil, but
two appear to be running lean and we suspect an air leak ... hmmm...
So, where's the oil going all of a sudden? WIth the other cowling off
I check the oil separator bottle... Almost empty... hmmm...
(I won't elaborate on the oil separator, it uses a quart Mason jar and
separates the oil mist from the crankcase and the wet vacuum pump -
unless you are really old you have never seen anything like it.)

So the brain storming started... the belief at this time is that:
1. a failed bottom plug oiled up because it was not firing
and was simply a coincidence, whilst
2. a new induction leak is causing the lean cylinders to burn oil
we suspect that the induction leak is in the oil pan

The plan at this point is to fly the plane at 23/24 on full rich and
measure the oil burn and fuel burn on each engine... Then fly it
leaned and recheck the oil burn and fuel burn on each engine.... This
is baseline info...
Once that is accomplished we will pull the bottom cowl (major job
involving disassembly of the air intake system, which is why it waits
on the flight test) then ground run it using a can of carb cleaner as a
probe to see if we can find a leak...

Good thing I own an airplane otherwise I would NEED a hobby to use up
all that excess time and money I have...

denny


There could be a reason for the bad plug. Pull the cowl and check the
"cigarette" leads at the plugs for crud, streaking, carbon. This
condition will cause misfiring and poor performance. You can pull the
cigarettes loose and clean the insides (and the insulation) with either
denatured alcohol or lacquer thinner.