"Perry J. Mick" wrote:
I've noticed a strange problem lately though. I've only
recently started continuous operations above 5000 RPM,
so it could have been there before but didn't notice.
Climbing out if I leave it at full throttle (something I never
used to do after the first 1000 feet) the oil pressure slowly
drops from 80 to 40 psi. If I level off and remain above
5000 rpm the pressure stays low. But if I back off the
throttle to around 4800 the pressure suddenly goes back
to normal 80 or so within 5 seconds. Oil temp remains
stable at 200 throughout.
In cruise if I then increase the throttle above 5000 rpm,
the pressure will slowly drop down to 40 again, over
a period of a few minutes. Reduce the throttle, pressure
recovers to 80 in a few seconds. Any ideas?
I called John at Mazdatrix, he thought maybe a bad
sender, which is easy to check. I'll replace it tomorrow
morning and try it. He also thought maybe the front pressure
relief valve (I don't have the Mazda books here in front
of me so don't know if that's the right name) may be
leaking, and mentioned putting some spacer washers
in it.
I'd like to find the problem and fix it, but haven't been
overly concerned since Tracy flew to OSH and back
with 37 PSI oil pressure. Can you rotary experts out
there give me a clue?
--
Perry Mick
Duckt N7XR
http://www.ductedfan.com
I would track that done and not fly until you found the problem.
I hope it is not the old front cover O-ring problem again.
The oil pressure relief valve is at the base of the oil filter.
Unfortunately I think it will only show in the air, but I can stay
close to home base.
I mentioned the front cover O-ring, but John didn't think that
was it. He said you would have low oil pressure all the time.
I think that is called the oil pressure control valve.
In this schematic it is called the pressure control valve.
It is real simple and I can't see how that could cause a problem
unless it is sticking in its bore. Not likely. Maybe the spring
is broken. Real easy to get to if you drop the pan.
That's what he was talking about I think, the one in the front.
That one protects against overpressures of about 190 psi?
I think. He thought it could be leaking and said you could
put spacer washers in. I have a 13B in the hangar I can
take the valve off and inspect to try to see what he was
referring to.
--
Perry Mick
Duckt N7XR
http://www.ductedfan.com
The AirCraft Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org