Finn Lassen wrote:

No this is not the opposite of "cold feet".

Went flying again today in my 13B powered RV-3. Getting more
comfortable, although my heart pounds a bit faster on any new sound or
vibration.

I think it was about 90F outside today. No real cooling problem as such.
Did see oil temp as high as 198 C (223F in oil pan), and water temp as
high as 190F.

Today I noticed that my left foot is getting uncomfortably warm - though
thick-soled shoes . Is is normal that the bottom forward skins get real
warm? Of course, I my case the muffler is on the left side and air is
blown past it, hitting the left side of the firewall and forced down and
out (and also past the left side skin, which I've learned not to rest my
left hand against).

Another point I need to solve is when reducing throttle to maybe 3500
RPM the mixture reads lean and EGT goes up. Mixture is fine above 4000
RPM and below maybe 3000 RPM. Of course, the ultimate solution is to
switch to fuel injection - but that's in the future.

Finn

Finn, the muffler is probably "red" hot  (1,500+ degF) and unless you have a
heat shield a lot of heat is being radiated into the surrounding airframe. A lot
of people construct heat sheilds around the exhaust pipe/muffler with an air
gapto prevent radiation. Thin stainless sheet works fine and leave at least a
1/2" air gap. You can do the same thing to shield the firewall. They also make a
fireproof blanket material (see Aircraft Spruce) that also is a good heat
shield.

Rotaries make lots of heat, and as I've been told, Mazda keeps the exhaust temp
down under full load with excess fuel. My experience has been that as I lean out
the engine the temp goes up, until the power starts to drop off, when I'm in a
lean condition. Actually, all IC engines work this way.
 Chuck

If you lean it enough in all IC engines the EGT will start to go back
down. That is what is known as running 50 or 100 degrees lean of peak.
True the HP goes down but you want that anyway for cruise.

Unlike a piston engine the rotary has no exhaust valves to worry about
burning so this is a very viable way to reduce the exhaust temp and
improve the MPG as Tracy Crook has demonstrated. If you screw up running 
lean of peak with a piston engine you risk burning an exhaust valve.

BTW This is a very important side benefit of EFI with manual leaning as 
compared to motorcycle or automotive carbs without leaning capabilities.

Tracy's EFI design has this manual leaning capability.

Paul Lamar
 
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