Art,
With the cylinder temp going to 500 degF, I would be very
concerned that the engine went into pre-ignition. In pre-ignition the
cylinder temps go up “fast” and the power falls off. Did the
plane slow down? However….and coincidentally I have flown
from AZ to SOCAL and back both of the last two weekends and both times I had to
leave the cowl flaps open to keep the #1 cylinder head temp from going over my
personal bogie of 380 degF. I was at 11K to 12K and the outside air temp
was quite warm. I was flying my TNIO-550 Bonanza at 75 deg LOP and 2500
rpm/30inHg. (16.7 gph) Yes, I was going a lot slower than you were.
The concern with pre-ignition is it can take out the top of a
piston in just seconds. Look for anything that could make itself into a
glow plug as the engine heats up. Thread of a spark plug sticking trough
into the chamber….anything like that.
Craig Berland
Had
an interesting thing happen on a flight from AZ to
So
Calif. Cruising at 14500ft had been in cruise about
40
min. was running 2600RPM 31" 18GPH about
75
deg. LOP. The temp on #1 cylinder went from 315
to
500 oil pressure dropped to 15 oil temp went from
178
to 197. I went full rich reduced power to 17" and
went
to nearest airport to land, this action brought
temps
back into normal as well as oil pressure to 38.
On
the ground I removed the top cowl to be sure there
where
no oil leaks and found non. Refowled plane
took
off and did some laps in the pattern everything
normal
started home and at 8500 ft and 30 minutes later
same
thing CHT 425 oil pressure 21 oil temp 174. I had been flying at 2500/22".
I reduced power again and temps
came
back down, I continued home. I since have removed
the
cylinder and have had it inspected by 2 competent
mechanics
and no damage. The engine has 260hr.s, does
anyone
have any ideas as to the problem?. Your thoughts
and
ideas would be appreciated