Paul,
Any cool area that cannot enter into the combustion process will lead to wasted energy.
An example would be the area above the side seals.

I went the opposite way.
I increased the turbulence and flow at the sparkplug and found a measurable difference.
The burn rate increased as shown with combustion testing.
It then required removing 2 degrees of timing. (see attached)

The best solution IMHO would be a way to seed the chamber with a catalyst-like substance
that would simultaneously ignite over all of the rotor face captured area.
Barry Bordes

Yes but it is not enough to affect the BSFC by 10%. Something else is going on.
I think it is the wind in the combustion chamber.

Your catalyst might work.

You also need a way to test the BSFC.  If you have a prop on the engine
and you run it at a constant RPM long enough to burn a gallon of gas
you can test the BSFC by how long it takes to burn a gallon.

The longer it runs the better the BSFC of course.

It will be hard to measure the effect ( if any ) on that NACA duct.

Paul Lamar



Hi Paul,
 Further to my thoughts on CC turbulence. It is well known
(as you know) that recip engines rely heavily on this effect. In two valve per cylinder  it relies on "swirl" as the mix comes in through one valve and out the other. This spin effect is increased as the piston comes up, rather like an ice skater as they move their arms in to greatly increase their spin. In an engine with two valves per cylinder it "tumbles" instead rather like an acrobat or diver doing a forward roll. Possibly the turbulence could also be improved by injecting hot air in through the trailing plug hole (NOS would be better !) this will give a small (or even big) supercharging effect also. Of course this will affect the mixture and must be allowed for.
 Chris.
 p.s. no need to put this in if you think it's all bullshit.


There is a very Fundamental difference in the moving combustion chamber of a Wankel
and the fixed combustion chamber of a piston engine. Apples and oranges.

Paul Lamar


   The trailing plug would be too late in the intake for the cooling effect of the NOS injection to provide a "supercharging" effect. Injecting about 45°after the intake opening in combination with direct fuel injection as illustrated in photos from Mazda of the 16X rotor housing.
   Also incorporation of the Far Trailing plug as used in the Le Mans winning engine would help with BSFC and emissions. NOS is only good for short power bursts.

   My feeling regarding hydrogen as a fuel is that it is a future possibility. In the interim, a focus on the use of natural gas would be more beneficial. It burns clean and can be used in modified diesel engines. In a rotary engine, fairly high boost pressure could be used on engines like the 10A and 13A with 3 spark plugs. Using Paul's ignition system for very complete combustion would provide high power and low emissions. Natural gas is inexpensive and fueling can be done at home overnight or at quick fill stations. Fuel costs for a year of driving should be less than gasoline providing driving conditions and miles driven remain the same.
   Dale Davies


   What does all that have to do with the squish flow?

   Paul Lamar



   Hi Paul,
       When I re-read my missive on turbulence I noticed my second instance
   involving " tumble " was meant to read four valves per cylinder not two.

    Cheers Chris Hoskins


On recip engines in the early emissions days lower compression ratios were desired thus the Big Three made use of open chamber heads. These had larger combustion chamber volumes and tapered to the cylinder walls. Newer research has found the quench heads better. Ford and the others developed heart shaped combustion chambers that enhance combustion efficiency.

As Barry explained swirl from a two valve head speeds the spread of the flame front.I believe the air/fuel squished out between the quench part of the head and the rising piston also promotes tumble. Too much can be detrimental. In four valve heads tumble is more prevalent. The Detroit Diesel two strokes had the inlet ports at an angle to initiate swirl.
Even though the rotary combustion chamber works differently, I believe combustion theory applies as Laws of Physics. It is just a matter of determining what works best. I believe Barry's findings corroborate what the other auto manufacturers are finding.


Somender Singh got a patent for "groove" technology that helps with swirl and possivly tumble. If grooves were machined into the trailing side of the rotor face to direct a blast of air/fuel forward past the spark plugs to carry the flame to the front edge and then back down the sides may help fuel burn. Using the far trailing plug would also help if possible to incorporate. The third plug would tend to send a jet of rapidly expanding flame along the groove.

Dale Davies

None of the first two paragraphs  is applicable to the rotary. Apples and oranges.

Do you have any drawings or the patent itself? Or just the patent number?

Paul Lamar


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