http://www.nzherald.co.nz/motoring/news/article.cfm?c_id=9&objectid=11164644



Its got side-port intake, so its just a periport and exhaust port
massaging away from double the HP!

-Dan


"Yamanouchi had said the main problem with rotaries was the lack of
torque and need to rev hard, thus using a lot of fuel. His solution
was large displacement engines, far bigger than the 12A, 13B and
20Bs the company has produced over the years. Suzuki confirmed that
passenger rotaries were still very much on the table."

Hmmm...

Their relationship is far more than arms length these days ( Mazda /
Ford ) but the Eco-Boost System used on a couple of their engines
have a flat torque curve ( which IMHO was pretty revolutionary and
no one saw it ) , my guess  is this is achieved by modulating  the
turbo-design and the wastegate. Why would not be this a natural
application for the Rotary and not have to upsize ?

Anthony AKA John Smith :)


They are wrong.

All they need is a European style auto shafting manual transmission
for better acceleration. No need for a bigger engine.

The rotary engine suffers from high BSFC at low loads. Low loads are
the name of the game for automotive engines. GM found back in 1978
that the temperature of the rotor face had a strong effect on the low
load BSFC. A 9.8% improvement in the BSFC was possible with a hot
rotor at low loads. Higher rotor temperatures  gave lower fuel burn
at low loads. However if the rotor was not cooled at high loads the
cast iron over heated. GM got a patent in 1976 on a hot rotor face
insulated from the rest of the rotor. Here is a pdf on the 3,995,602
patent. The SAE GM paper on the subject was 780419.

The obvious solution is to control the temperature of the rotor as a
function of the load on the engine.

The amount of oil cooling on the rotor is now controlled by a ball
and a spring that opens at a certain RPM. RPM is not the problem.
Engine load is the problem. A way can be found to cut off the oil
cooling to the rotor at low loads regardless of the RPM. In other
words run the rotor face as hot as possible at all RPM's.

One mechanical way of doing that is insert a stationary tube in the
center of the e-shaft that moves back and fourth controlled by a
servo that senses engine load and cuts off the cooling oil supply to
the rotor. A piece of cake for todays computer controlled engines. In
fact it need not be controlled by a computer or electrical servo but
by a simple air servo connected to the intake manifold pressure.

Patent applied for :)

Here is another way.

Install a small cruise rotary engine bolted to the RX8 diff. A
mechanical hybrid so to speak. Take advantage of the small size and
light weight features of the rotary engine.

Get an AIXRO Kart engine and mount it on the back of the RX8
differential. Remove the stock rear cover.  Use a second pinion gear
and run the AIXRO only at cruising speed with a one way clutch to
disconnect it at lower speeds.

Assume a 30 inch diameter tire and that gives a 94.248"
circumference. That is 7.85 feet in circumference. At 95 feet per
second or 65 MPH that is 12 revs per second or 720 RPM. Multiplying
by the 4.77:1 rear axle ratio yields 3434 AIXRO engine RPM.

So you will need a 2.17 planetary gear reduction given 7452 RPM max
HP for the AXIRO engine. That is also 114 revs per mile... per hour
or 96 MPH at 11,000 AIXRO max RPM.


My guess is the MPG running on the AIXRO alone will be .73/.52 X 25
will be about 35 MPG. Converting the AIXRO to an oil cooled rotor and
EFI and the RX8 MPG could jump to 38.8 MPG.

Going the full turbo compound route on the AIXRO and getting the BSFC
down to .4 or below the RX8 MPG would jump to .73/.4 X 25 or 46 MPG
at a steady 65 MPH.

The cost of testing this is not beyond the means of an individual.

Paul Lamar

     Interesting proposal. Some old research, I can't retrieve the reference now,
   pointed that the HC in exhaust are in reverse relationship to the Rotor's
   surface temperature, the higher the Rotor surface temperature, the lower the
   exhaust HC, and also the Yanmar Diesel research pointed that a TDR rotor
   recess reduced the HC in exhaust respective to a MDR or LDR recess, this is
   because of inherent features of the flame propagation in RCEs:
   'Combustion and emission properties of Rotary Engines'; Automotive
   Engineering, July 1972, pag. 26-29, (full issue download $14 at SAE.org)
   based on SAE paper 720357 by K Yamamoto et al ($24, same site).

    The effect of rotor recess shape on performance and emissions of RCEs
    seems being dependent also on the number and placement of plugs,
    Toyota showed best results were obtained with a glow plug in the
    leading site, I don't know if such plugs are available in the market for
    something different to model engines, but it would be interesting
    having the opportunity of testing a glow plug in a full size RE.

   As discussed previously, US patent 3848574 by Kawasaki proposed
   changing the shape of plug hole to a wedge, with the end pointing to
   the trailing edge of Rotor, to improve combustion, power and emissions,
   I've hired from Kevin Landers in rotaryresurrection.com the implementation
   of this change in a 13B engine, and I've done it myself also in a Sachs KC-27 engine
   from an Hercules  W-2000 motorcycle, when I have some data bout the results,
    I'll let you know.

      How do you intend to change the Aixro charge cooled rotor into an oil-cooled
      version?  It seems a hard work, and I can't imagine the way for this.
       Thanks for your attention. Best regards. Salut †
               Jose Gros-Aymerich
                 Madrid, Spain

Add an oil pump and replace the needle bearing with plain bearings.

Paul Lamar


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