I may be the current leader of discovering failure modes
in this allegedly robust engine <sigh> :-) before flight. Ed, I
leave the gliding championship to you. I must admit that the idea of
pulling the engine is not quite as daunting since I have moved past the
proof of concept mode and have got my flight ready install pretty much
set. This makes the engine removal, and then the re-install much more
of a methodical process than a somewhat overwhelming
dismantling...guess practice makes perfect. <sigh>.
All the best,
Chris
Perhaps not the world leader. I built an engine that ended
up in a Mini Cooper, in an "Inline" orientation with a Narrowed Ford 8"
rear axle. Front suspension was from a Chevy Chevette. Same one was in
the Corvair and the Pontiac Fiero. Home built 3" square tube chassis.
He let it sit for two years then ran a weekend of Autocross with no oil
pressure. Thought it was the gage no working. He gave that rotary away
and put in a Chevy V-8.
The rotary has poor compression due to long seal lengths and
many end gaps. It does have enough compression ratio, but that is a
calculation that leaves out any leak rate. The rotary has a high leak
rate.
Rate must include a time factor, and that time factor is how
fast can the starter turn the engine. It can turn the engine faster
with poor compression. It has that, so the starter sounds very
effective. The poor starting with the prop installed vice the better
starting without the prop should be evidence of this.
The large combustion chamber produces poor fuel
vaporization, and many fuel droplets will condense and cling to the
interior surfaces. This is a very lean mixture as far as starting is
concerned. The correct amount of fuel per pound may have been injected
to run the engine at a fast idle, but it is of no value without
vaporization.
A faster starting RPM reduces the time available in the leak
rate and reduces leakage, improving compression, raising charge
temperature (heat of compression) and improving starting performance.
If the vaporization improves, the effective mixture is
enrichened.
The rotors are made of Nodular iron. The apex seals of cast
iron with electron beam heat treating of the wear faces. They are a
close fit in the grooves. Both exhaust ports and intake ports are
always open to the outside world. As fuel droplets flash off they lower
the rotor temps and the air gives up its water, inside your engine.
The apex seals stick in the grooves the first time they can.
Stick a plug in the exhaust pipe right after shut down. Always run the
air filter during operation and after shutdown until the engine is cold.
I have been building engines and rebuilding other builders
engines, since 1980. I have never removed a broken apex seal spring. I
suggest that you have a stuck apex seal. Try a freeing product that
includes a rust remover like Hydrochloric acid. As soon as the seal
comes loose, run the engine for as long as is possible (water temps).
Then spray in some motor oil and turn the engine a few revolutions.
The acid eats iron rust and nonferrous metals like candy.
Wear eye protection and rubber gloves. Outside off the concrete.
Motor fuel is a cleaning solvent. Even with a bit of oil in
it.
The spark plug in use may add to the poor starting problem.
If no actual loading is expected like high speed taxi or flying, then
the plug heat range is of little matter (medium or retracted tip shape.
Gapped at about .020". The multiple ground plugs that look like
airplane plugs are easy to short out, and look like a capacitor. A
single ground strap (small square wire) shortens rise time and
concentrates energy in one location.
Until the engine is broken in, you might premix one Oz. or
more per gallon of whatever top oil. Sealing will be great and starting
easy.
If you remove the rear iron. Clamp all of the stack together
with bungees/springs and, or safety wire. Even the rear rotor housing.
So long as none of the pieces can move apart, no problems will spring
up.
Full throttle and load limited to 6,500 RPM, is racing in
anybodies book. Nobody in racing uses a spark plug that can be found in
a Mazda dealership.
Lynn E. Hanover