Short Article by Paul Lamar published on the News Letter March 4th 2006

This is from the 1954 SAE Transactions. Development of the R3350 Turbo
Compound Engine. The book in the Caltech library had a 1 mm coating of
dust.

See the chart illustrations on the web site.

The power recovery heat balance chart knocked me out of my chair.
I had NO IDEA.... NONE WHAT SO EVER, prior to now, so much energy
was wasted by the exhaust valves in a piston engine turbo compounds.
Need I mention yet again THE WANKEL ROTARY HAS NO BLEEDING
EXHAUST VALVES!!!. More evidence we will eventually get more than a 20%
efficiency improvement with a turbo compound rotary.

Lets look at the heat balance chart with out the exhaust valves.
Total heat available to the turbine now over doubles to
34.7% from 14.9%. The losses to gears and bearings also doubles
to say 3%. Windage and cooling loss goes to 3.2% from 1.6% and
aero and thermal losses got to 12% from 6%. Total loss percentage
is then 18.2%. 34.7% kinetic energy available for recovery
minus 18.2% losses is 16.5%! Up from only 6% with exhaust valves.

Total fuel energy burned in a 200 HP rotary is about 760 HP worth.
With exhaust valves you would have only about 6% or
45.6 HP available for the turbine.

Without exhaust valves you would have about 16.5% or 125 HP!!!!
Almost three times the HP available to drive the turbine!!! No wonder
you can boost a 13B rotary to 800 HP!! There is lots of kinetic HP to
be had in the rotary engine exhaust. Much, MUCH more than I had at
first thought. We always knew there was a lot of waste heat in
the rotary exhaust. Up to 50% of the total heat. What we did not
know up until now was what we could expect in terms of kinetic energy.

Chart "R3350TC-take-off-heat-balance". Out of a gross total of 3750 HP
the supercharger was consuming 385 HP. Subtracting 470 HP mechanical losses
from the gross total gave us 3630 net HP to the prop. Now look over on the lower
right side on the chart. The basic engine was 2750 HP sans turbines. Same as the
B29 engine.  All three turbines generated the takeoff HP increase or 880 HP. Divide
by three to get individual turbine HP's and you get 293 HP per turbine for this
R3350TC engine version.

Overall efficiency with a 10:1 air fuel ratio for take off was 17% without
turbo compounds and 22.3% with the turbines. Or an overall engine efficiency
gain of 5.3 percent at high power. Now the sensible power going to the turbines
is with the huge losses to the exhaust valves. About THREE TIMES AS MUCH will
be going to the turbines WITHOUT the exhaust valve losses. Chart three. "R3350TC Power
recovery heat balance." 

The power in the Mazda Wankel rotary engine exhaust has been talking to us for 30 years.
It has been saying. "Hook me to turbine, hook me to a turbine, hook  me to
a turbine." Anybody that has been around a Mazda rotary powered race car
without a muffler can understand the tremendous kinetic energy in the exhaust.
I have a race car driver friend by the name of John Morton who claims he
has permanent hearing damage from driving rotary powered race cars.

It was not until I read that SAE paper on the R3350 TC that I could put
a number on it. It then hit me like a supersonic shock wave. Yes of
course it has plenty of kinetic energy in the exhaust.

Now comes the time to harness all those super sonic horses.

Think of the Wankel rotary as an ideal gas generator for a turbine
engine.  A marriage made in heaven.

We are now building a traction drive device to extract the excess HP from
a stock turbo charger. Input speed RPM can be up to 120,000 RPM and output
RPM will be one tenth of that. The power from the traction drive output shaft 
will be transfered to the e-shaft of the rotary by a multi v belt to absorb
the torsional vibrations from the rotary engine. We hope to recover at least
50 HP from the waste heat in the rotary exhaust improving the BSFC from
the current .47 to .376 at cruise altitude. The range of any airplane using
this engine will increase by 25%. We hope to test the engine soon on a dyno
and a SAE or AIAA technical paper will be published reporting the details
of the traction drive and the dyno test results.

Paul Lamar