Paul, I don't know if you have this covered in your drawing,
but there is an oil seal of some kind pressed into the TC PSRU
base plate. I'm shipping it out today to Jeff.
C. Smith

Yes the oil seal counter bore on the back side of the plate is in the
3D I sent to Jeff.

Here it is in Tracy's dwg.
Did you notice a shallow counter bore on the front side?
I am not sure he is still shipping them this way.

What is not is the mounting holes for the starter. I found an error
in Tracy's dwg so I left out the holes. It is easy to match drill
the holes once you have the 2nd gen starter.

Jeff, please take some pictures of the final product and send them to
me.

I'll put your name in address in the parts for sale section on the web site.

BTW we also need some one inch OD spacers drilled and two of them counter bored
for the hollow dowel pins. That can easily be done on a manual lathe.
Of course an NC lathe could knock out a bunch at low cost.
Craig has a set of spacer blocks from Tracy's that are rather crude
but the correct length can be determined by measuring those.

Paul Lamar

Answers. No counter bore present on this plate.
I have pictures, will send later today.
Are you talking about the blocks that support the plate from the engine?
I can photograph and or measure the hardware supplied later today after I get back home.
C. Smith

Thanks.
Yes about the blocks.
I suggest we replace these with spools made from one inch diameter aluminum
rod. Then tig weld 3/16 thick 6061 T6 plate between the spools as in
these pictures. The 3/16" plates take only the modest shear load due to
the 200 foot pound engine torque. The 700 foot pound prop torque is
taken directly by the motor mount/adapter plate combination.

Its optional. It is mostly a weight issue. The blocks
are too heavy for what they do however they do work.

Did you ship the stock Tracy plate off to Jeff yet? Are you shipping the
blocks as well?

Paul Lamar


Paul, since I have only been on the mailing list for two weeks I will ask
questions that probably been answered long ago, please bare with my
ignorance. One, what is the stock mazda car engine mount system?  What about
Dave Atkins engine mounts tabs? And are dynafocal mounts worth it?  Also do
you have a web site with a price list for P-porting and your other parts and
services?  I heard while low rpm may be a problem with a P-ported engine,
there also may be a resonance problem with Tracy's drive reduction below 700
rpm.

Finally for direct drive turbo-compounding I desire the highest recovery at
cruise rpm (about 6,000rpm). Displacement x VE x Rpm x Heat loss should give
the CFM of exhaust gas therefore if the turbine was designed for a larger
displacement engine the rpm should be proportionately slower,or two turbines
connected to the E-shaft would split the CFM for the same effect, Am I
making sense?
Dave James

Nobody uses the stock mounting system as it is too heavy.

It also it gets in the way of the exhaust system.
I know nothing about Dave Atkin's tabs.

The rotary does not vibrate like a piston engine so dynafocal
mounts are not really needed. The rotary only vibrates around
it's longitudinal axis.

Mistral uses them so they don't
have to build motor mounts. They can also beef up the housing parts where
necessary to take the cantilevered loads implied. The rotary is
not designed to be entirely hung off the front cover. Especially
with a heavy PSRU on the aft end.

All gear boxes have resonant problems with low RPM.
the 2.85:1 GB ratio means the engine idles at 2000 RPM when the prop is
going 700 RPM.

In aircraft use the engine is not called on to generate significant power below
5000 RPM so P-ports of any kind are no problem. The p-port RX8 engine with side
exhaust ports has no more problems with low RPM than any other 13B engine
made since 1974. In other words the valve overlap is the same.

The blade velocity should be half the exhaust gas velocity. If you have
more gas volume make the blades wider or longer or a little of both.

Lots of info on the web site below so read that.

Paul Lamar