I think that I
would see air under the radiator cap if I had a compression gas leak?
I never see any air.
To check a piston
engine for head gasket leaks, you would put the cylinder at TDC and
pressurize the cylinder to about 150 lbs with compressed air and check the
radiator for air bubbles…How do you check a
rotary?
I will check the
pressure sender against a mechanical gage.
There is obviously
a heating problem, but I think the pressure is higher than it should be
until just ready to boil. I shut the engine off at 210*, and at 22+
lbs, the boiling point should be well above
250*??
Thanks for the
suggestions of where to look, guys…
Bill
B
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Al p Wick
Sent: Tuesday, October 02, 2007 7:49
PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Coolant Water
Pressure
Your coolant reservoir should be above engine.
1) If it is, remove two cups of air from the
reservoir. Then repeat your test.
2) If you now see pressure rise above 22 psi
within 5 minutes of cold start, you clearly have compression gases leaking
into cooling system or bad gage.
3) Air in the block is 10 times more significant
than any other cooling factor. Make darn sure you don't have any. It causes
local boiling, high temps, strange
behavior.
Operating with two cups of air under cap is an
important safety and diagnosis advantage. Everyone should do it. With that
two cups, you only see 22 psi if you have a genuine problem. You only see 0
psi if you have genuine problem. The pressure is then a very fast and
reliable indicator of system integrity. So two cups of air has no negative
effect on system efficiency, just a substantial improvement in safety. Only
time it could be a negative would be if your reservoir was way too small,
way too low, or flowed way too much
coolant.
Since you describe high temps AND pressure, I
suspect you have temperature problem.
I deliberately overheated my engine many times so
that I was intimate with pressure and temperature patterns. Then tested
various concepts. Don't recommend you do the
same.
I just recently got my Renesis
started again after finishing my cowl. I seem to be getting very
high coolant pressures. I can only run the engine about 10-15
minutes before hitting the redline at 210*. My water pressure is at
27 Lbs at that time. I only have a 22 Lb radiator cap, so I assume
that I am blowing into the recovery tank, but I have not confirmed
that. My oil temp has never exceeded about 165*. It might have
gone higher if I could have run longer???
This whole water pressure
thing has me a little baffled. Since this is a closed system and the
only way pressure can build is due to the expansion of the coolant after
heating???, I am confused by some comments that have been made from time
to time. I remember something that Tracy said about his pressure would build
for a time, then go to zero. It seems to me that the pressure should
correlate to the temp pretty closely since it is a closed system??
Can someone enlighten me a
little on the science of this pressure? It seems to me that there
could be some pressure build up on the positive side of the pump, but it
would go negative on the suction side, so the net effect of the pump
should be close to zero??
Also, my Renesis had only 1800
miles on it when I bought it, so I did not have to tear it down. As
a result, I am somewhat in the dark as to how the water flows through the
system. Could someone help me with that? I had to remove the
thermostat tower for height clearance , so I made an adapter plate that
takes water from the top outlet of the pump and sends it to the radiator
(double pass), then from the radiator, it returns to the lower inlet of
the pump.
Thanks,
Bill
B
-al wick
Cozy IV powered by Turbo Subaru 3.0R
with variable valve lift and cam timing.
Artificial intelligence in
cockpit, N9032U 240+ hours from Portland, Oregon
Glass panel design, Subaru
install, Prop construct, Risk assessment
info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html