Paul,

 I just got this reply back from the people in England
 selling the billet aluminum rotors.
 As you can see one weighs 8.25 lbs.
   [2.2.bs x 3.75 kgs = 8.25lbs.]

 Hi

 I've just put one on a scale at 3.75kg

 Regards
 Gary
 RotaryArt team
 Unit 4 Lambwood Hill Ind Est
 Grazely
 RG7 1JN
 + 44 (0)1189 888555
 + 44 (0)7973 111555
 www.rotaryart.uk.com

 Compare this to the machine lightened Renesis rotors at 9 lbs.,
 or 9.2 lbs stock, and for aircraft operations the 3/4 lb weight
 savings wouldn't be worth it.  Mainly because of the same issues
 homebuilders face today.  That is:  To capture the horsepower
 POTENTIAL of the engine, we pretty much have to enhance, alter,
 or improve every component that  goes into the engine.

   Some issues to consider with the Al. rotors are expansion
 coefficients of aluminum verses iron, rotor heat retention
 characteristics and hence cooling, apex seal encapsulation
 strength and bearing lubrication.  In reality the bigger
 challenge might be  PSRU design and matching propellers to it.

 Doug in Japan

 They are made in Florida. With solid aluminum rotors one would
 not expect much else. The cast iron rotors are at least hollow.

 I don't agree with "we pretty much have to enhance, alter,
 or improve every component that  goes into the engine."

 The stock Mazda rotary is ten times as robust as your average
 automotive piston engine. It is as long lasting as
 a much more expensive aircraft piston engine made from
 far higher strength and costly materials and more costly
 manufacturing processes.

 Other than a couple of holes in the stock rotor
 housing that is about it. Yes the stock intake manifold is
 near useless. This slightly modified rotary engine will put out
 250 HP which is equivalent to a 100 pound heavier six cylinder
 aircraft engine.

 I know you know all this Doug.

 Paul Lamar

    
G'Day Paul.
Perhaps I have it wrong, I thought one of the ways to improve the
fuel economy of the rotary was to run it lean. Would this not
potentially expose aluminum  rotors to the risk of getting
burnt as happens with stroke pistons when they run lean?

John Evans                   


The EGT actually goes down when you run the engine lean.
You are more likely to damage the alloy rotors under full power.

The rotary is unique as it has a rotating combustion chamber
so the fuel molecules are thrown outwards towards the spark
plugs. Sort of naturally stratified charged. Unlike a piston
engine it will run fine at 17:1 to 18:1 or leaner. Power will be down but
BSFC or fuel burn per HP will also be down. So too EGT's. In other
words the engine gets much more efficient in the lean burn area.

Paul Lamar