High EGT
Posted: Sun Feb 19, 2012 12:15 pm
I have solved all of my engine problems except one. High EGT. 1200 F at
2000 RPM rising steadily to a bit over 1600 F at 5000 RPM. About 1500 F at
3500 RPM. My initial timing is 14 degrees with a maximum of 18 degrees of
advance from the distributor which is reached at 3500 RPM. Max total timing
is 32 degrees advanced. The engine starts and runs beautifully throughout
the RPM range from idle to max power. The spark plugs look perfect, not
showing too rich or lean. No fouling. Oil and coolant temps right where
you would want them. I changed out my regular unleaded fuel for 100LL.
(EGT problem the same before and after.) My EGT probe is about 3 inches
from the exhaust port on cylinder #2 which is nearest the firewall on the
pilot's side.
I am now convinced that the reason I burned a hole in piston #5 is that I
was paying too much attention to EGT readings before when setting my timing
and I was way too far advanced in an attempt to reduce EGT. I won't be led
down that path again so I am leaving the timing right where it is. There
has got to be another reason for the high EGT.
It is incredibly frustrating to watch day after day of precious summer
trickle away without flying. But I really don't want another short flight,
emergency landing, and a winter rebuilding the engine again. Any
suggestions would be GREATLY appreciated.
Mike
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2000 RPM rising steadily to a bit over 1600 F at 5000 RPM. About 1500 F at
3500 RPM. My initial timing is 14 degrees with a maximum of 18 degrees of
advance from the distributor which is reached at 3500 RPM. Max total timing
is 32 degrees advanced. The engine starts and runs beautifully throughout
the RPM range from idle to max power. The spark plugs look perfect, not
showing too rich or lean. No fouling. Oil and coolant temps right where
you would want them. I changed out my regular unleaded fuel for 100LL.
(EGT problem the same before and after.) My EGT probe is about 3 inches
from the exhaust port on cylinder #2 which is nearest the firewall on the
pilot's side.
I am now convinced that the reason I burned a hole in piston #5 is that I
was paying too much attention to EGT readings before when setting my timing
and I was way too far advanced in an attempt to reduce EGT. I won't be led
down that path again so I am leaving the timing right where it is. There
has got to be another reason for the high EGT.
It is incredibly frustrating to watch day after day of precious summer
trickle away without flying. But I really don't want another short flight,
emergency landing, and a winter rebuilding the engine again. Any
suggestions would be GREATLY appreciated.
Mike
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username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
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