There are surely tradeoffs in charge cooling, the advantages are no oil
cooling hardware, the VE goes up as load is applied due to the additional
Air fuel ratio passing thru the engine. The Charge cooled track and or
intake length increases the torque and flattens the torque in this engine is
flat from 3000-8000RPM. The path naturally atomizes fuel due to the passing
thru the rotor. Some of the above benefits are opinions and speculation due
to the inherent differences in our engine compared to the Mazda and the fact
that these above stated characteristics show a major difference in
performance characteristics out of a very similar sized engine 650cc/rotor.
I hope this provides you some answers.

Note: The engine loves cool air, full load, and alcohol as stated above the
VE gets better as you introduce anything that cools the rotor and or the
intake charge.

Eric Barger

Eric,
Not knocking your product simply trying to understand and evaluate the
differences between your product and the Mazda.

Interesting point is that the passage through the rotor increases the
torque, or put another way, increases the tuning effect of the inlet
manifold or reduces the length needed of an external manifold. If I am
correct in interpreting your comments in regard to this, can you comment on
the internal length in question.

Also what sort of compression ration is in your engines?

Also I have had many a discussion with Mistral on aluminum side housings -
we all appreciate the weight savings, however what sort of surface
preparation do you use? My understanding is the substrate is the major
hurdle to overcome, it that if it fails any surface goes with it. The
solution is to build sufficient depth into the surface treatment to
establish density/ strength to support the surface.
George (down under)





George,

We don?t take any comments as knocking our product like any other mechanical
device we have advantages and disadvantages, and quite frankly we appreciate
input and comments from this forum.

We run 8:1 compression ratio originally it was 10:1 and that did nothing but
increase the charge temp and lower the torque.

Intake length is approximately 8" from injector to intake stroke. (This is a
rough guess knowing the engine dimensions)

Coatings a 6 month challenge and several engines later we have what we
consider to be a bullet proof coating combination. We don?t give the exact
coating information out although I can comment and say it is plasma sprayed,
is ground and lapped to finish at .010 thick.

Coatings, seals, and the manufacturing process to get to a production ready
engine is more of a hurdle than anyone can appreciate until they have went
thru it. Rotary engines are simple and have minimal parts that is a good
thing if it were an IC engine we would have never made it this far as with
minimal parts you can focus your team in on each and every part or process
that needs attention and enough of that persistence then produces what we
are proud to call our GEN II engine. We are very excited here to be at a
point where we can get engines out in various applications for third party
testing and acceptance.

Again I appreciate the input and especially areas as Paul has shared from
previous rotary attempts and or hurdles, because at the end of the day we do
not want to learn the hard way if someone else has learnt and is willing to
share the results.

Eric Barger


The people I have talked to that have built successful all aluminum rotary engines swear
the only thing that works  well is silicon carbide detonation coatings diamond ground.
This is expensive. It is what Mazda used on the Lemans four rotor. Many have tried other
things and have failed.

The issue is the modulus of elasticity of the aluminum rotor housing wear surface.
There are two springs involved. The spring behind the apex seal and the
spring of the wear surface. Steel is three times stiffer than aluminum. That
is the main reason Mazda lines their rotor housings with chrome plated steel.
Chatter is the penalty for failure.

The aluminum foundry I deal with, American International in San Fernando
Calif.,  claim they can cast in steel liners no problem. I have been there and seen
dozens of casting with cast in steel parts. If it were me I would copy Mazda exactly
with the steel liners. Way cheaper than detonation coated diamond ground aluminum.

Wankel Germany went belly up when some of the Nicasil wear coatings on aluminum started to
flake off. There is no real way to control the quality.

Mazda has built 2 million engines and spent millions on R&D on this subject alone.
Don't fool around. Copy exactly.

Paul Lamar ...No rotor no motor.

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