Hello:
Just new to this group. One question to you guys. I know most of the
weakness's of the piston engines, what is
the weakness of the 13B, 20B rotary? Has there ever been a rotor break

on a

rotary in a plane?
Rich

Nothing has ever broken in a rotary on an airplane to my knowledge.
The engine is cannon proof. People get as much as 900 HP out of
a rotary at 10,000 RPM with lots of boost and nitrous oxide for drag

racing.

They don't come apart unlike a piston engine.

We had one crash when a muffler was lost and went through the pusher prop
taking out a blade and then the psru came off.

In another case the fan belt came off and took out the ignition wiring.

We had another engine lose oil pressure on the ground before takeoff

because the

engine was mounted plugs up and that made the oil line from the oil sump
to the oil pump too long. This happened after 400 hours of flight time.
I don't recommend the plugs up mounting.

We have had several people severely overheat them but the
engine did not stop. Just leaked coolant when it cooled off.

Two in-flight fires right after take off because a cheap oil cooler split.
This happened twice in a row because the first split oil cooler was

replaced

with the same brand the second time. It looked like an oil cooler was made
in China and sold by Griffin Radiator.

Tracy Crook had several off-the-shelf external mild and 0-too-thin

stainless steel

mufflers destroy themselves. That is an on going development process. His

first

0.035 thick stainless tangential muffler under the cowl lasted for about

800 hours

as I recall.

A guy tried to use a stock RX7 manual transmission locked in second gear
as a cheap PSRU. It eventually stripped the gears but the output shaft

would

also have failed in any event sooner or later.

Another guy plumbed the external oil filter backwards and the
one way valve in the oil filter caused a lack of oil pressure
from time to time. Took a 100 hours or so to find this.

Did I miss anything else guys?

Paul Lamar

Ed Anderson wrote:

Think you covered things that went wrong in the air.  A couple of other
things perhaps worth mentioning, but fortunately mainly happened on the
ground.

1..   Tracy Crook and I both lost the Leading Ignition Module due to a low
Ohm resistor opening in the base.  Mine happened on the ground.  Tracy's
apparently happened in the air, but the trailing ignition system kelp him
airborne.  We both replaced the resistor with a higher wattage one and no
more problem.

2.  Use of a "rubber" oil line positioned too near the exhaust, caused it to
carbonize, leak oil onto the exhaust and a fire resulted.  Prop wash blew
flames back under the fuselage resulting in replacement of warped skins.
Careful selection, routing and installation is needed for oil and fuel lines
(actually anything that may be effected by the radiant heat emitted by the
exhaust) to protect them from overheating.

3.  I had a aftermarket EFI fail (no redundancy or fail safe modes as it was
designed for automobile usage), have since replaced it with one of Tracy
Crook's EC2s with redundant processors and other fail graceful features.

4.  Basically, few if any weakness of the engine itself as Paul mentioned -
its bullet proof, most of the weaknesses are with the auxiliary systems
and/or their installation..

Ed Anderson

 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.

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