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.
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