Paul, no problem to 9000 rpm.
But you should never need anything that high in an aircraft!
From one of the threads, "3ms will net around 115mj".
Price is higher, about $75 each.
Barry

The rotary is a high RPM engine. 3.12:1 PSRU's are in the works.

Paul Lamar


Paul,
I think you will want to avoid continuous operation in the 9000rpm
range because of the tooth loading on the stationary
external gear. (Yamamoto '71, p.49)
( see attached)
Barry

Very good Barry. I like to see references for claims made.
Thanks

They have made some advances in this area in 1984.
This is from SAE 841017. The solution was trivial and very low cost.
They added 3 small roll pins.

The paper is available on the web site.

http://www.rotaryeng.net/1984-recent-tech.pdf

Page 9.

Paul Lamar

Most rotary engine machine shops recommend the roll pins or circlips, as
mentioned, hardening treatment of the stationary gear
http://atkinsrotary.com/store/13B-Rear-Type-I-Hardened-Stationary-Gear-10015.html
as well as bearing and rotor clearance for engines that run above 8500 rpm.
Speed costs !!!

Graeme Riley

Most of that is done on the RX8 engine. The red line is 9000.
I think the gears are a bit wider as well.

Paul Lamar

Well there you go, I wonder if we could get hold of a 16x it probably
has more improvements. Mazda must have some tooling done. Just a quick
question regarding direct injection, if one was to increase
compression ratio to say 16:1 or higher would it be possible to
control ignition timing using the injection timing?
Graeme Riley

With the current geometry 16:1 is out of the question.
SuperTech might be using other geometry.
Supertec also claims a .44 BSFC. We shall see. The Mazda best
so far is .47.

Paul Lamar

Paul,
Lightening the rotors will help lower the load on the gears. But consider those test were for transitional loads . For
aircraft its like an RX7 pulling a loaded trailer up an endless hill.

Next problem with sustained high revs.... the water pump cavitates... depending on type and pulley ratios, for me it is
at about 7300 rpm and 43psi, (with a Rick Engman Remedy pump). 3rd gen pumps are very poor. 2nd alot better. Worth a test.

Have you guys addressed the leading spark plug cooling passages problem?
When Mazda spread the plugs on later 13B housings (for better burn-rate) the two most critical passages became smaller
to accommodate using same bolt pattern. These should be carefully ported. The 16X addresses this in its new breadth
dimensions.

Are you planning on using a variable pitch prop with 9000rpm only for take off?

Barry Bordes

Milo is working on a variable pitch gear box.

We have not found any problems with the rotor housing metal over heating.
Mark Steitle installed a "cyl head" thermal couple and it is less than
an aircraft engine cylinder head temperature.

Paul Lamar


Along those lines, has anyone tried the standard spark plug CHT thermocouple on the Mazda?  It would be interesting to know what the delta T is from Mark's embedded thermocouple and the spark-plug location;  generate a standard rule of thumb for future users.

Chris Cosman

It is kind of hard to do because of the spark plug recess in the rotor housing.

Paul Lamar

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