John;
It doesn’t surprise me a bit that
your temps are running up doing what you’re doing. I don’t recall
your configuration, and whether you get any significant natural convection
cooling. I’m surprised that your oil temp didn’t go higher. With
our props in back the best we can hope to do is to be able to do low speed taxi
and idle without overheating. It’s all about airflow at liftoff speed
and above.
If you chose to remove the thermostat
you should be able to tap out the hole with ˝ NPT and put in a plug. Put
grease in the flutes of the tap to keep the turnings from getting in the
cooling system. Change out the grease after about three full turns or so.
Best of luck,
Al
-----Original
Message-----
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of John Slade
Sent: Wednesday, March 31, 2004
5:34 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Requesting
more thoughts on cooling
I'm signed off and ready
to fly, but I'm a little concerned about cooling issues. I don't want to melt
anything in the first go around the pattern.
I'm finding that the
engine gets REALLY hot after about 10 - 15 minutes ground running, and I'm
wondering if that's to be expected, or if I have a cooling problem. Maybe
I should just taxi gently to the runway and launch to get airflow as soon as
possible.
For example, today I ran
it up and down the taxiway for a few minutes at fairly low speeds and around
2500 - 3000rpm. Then I did some static runups (maybe 3800 - 4000 rpm - all the
brakes will hold) and some EC2 tuning. Then I did some mode 1 programing
at various rpm. During this run I watched the water temp gradually
go up until it was over 200 and I shut her down. The oil was still down
around 140 - 160. I took the cowl off and found that everything in the engine
compartment was HOT. Radiator, oil coolers, hoses, intake, the cowl itself.
Apart from giving my cowl a REAL GOOD post cure I dont think I've done any
damage, but this doesnt give me a lot of confidence about whether I'll make it
around the pattern.
The thermostat is now in
place, and I get the feeling that I'd be much better without it. Once the
engine gets a little hot the water temps seem to "run away" if I'm
producing any kind of power. So... to remove the thermostat [3rd gen rew
engine] I have to remove the water pump and have the by-pass hole welded shut -
right?
Do you 13B drivers tend
to just taxi out at low rpm then launch? Would your engine overheat if you did
a 15 minute medium power runup? I'd appreciate any general thoughts, or
comments on how much ground running I should expect to get away with before the
temps get too high. Anything else I should check?