Dear Paul,

   I have been reading many of the articles on your website, they are very
   informative.  I have been looking for a good engine for a heavy duty
   gyroplane, and I was told a Subaru EJ25 is a good choice. However, I
   have not been convinced.  I would think the 13B would be a much better
   choice.  I owned a RX7 for many years, and when I sold it after an
   accident it had well over 150,000 miles and the engine was in perfect
   shape.

   I have a couple of questions and hope you can help me out. First of
   all, do they make brand new rotary engines?  If not then we can only buy
   old cars for the engines which is not easy to do in my country as cars
   must be destroyed after 10 years.  Second, how does the power to weight
   ratio of the rotary compare with that of the EJ25? The data I got just
   got me very confused.  The power for the EJ25 ranges from 165hp to 300
   hp.  This sounds rather strange, and with such power range the EJ25
   could have rather high power to weight ratios too.

   Best regards,

   Gordon Gao

   Soobs have a weak spot in heavy duty use. The head bolt threads fatigue
   in the aluminum block
   and then you have head gasket problems.
   Kind of common in piston engines with aluminum blocks. Seems like every
   GM North-star engine
   has failed. Same thing happened to my Honda Odyssey. That is with only
   40 HP average. Imagine what it
   would be with 150 HP continuous as found in aircraft engines.

   I have owned six Mazda  rotaries since 1973 and several went over
   300,000 miles.


   Paul Lamar


   Gordon,
              Soobs I have a lot of unfortunate experience but only in the 6
   cylinder.  At about 100 hours the inlet valves "tulip" and no longer seal.
   Happens fast at the end. You will shut down and then they will not start.
   Everything can be cured but as usual at big cost.  Ifg you want to spend the
   money in modifications, the 4 cylinder WRX soob is by far the best but then
   you have to find a reliable redrive and again they exist but at a cost.
   The rotary is far simpler and reliable and part of the attraction is this
   web site and others where advice and backup is always available. Soobs are
   fantastic in cars.  They are also heavy.  Neil


I live close to the calif. state rally champion running soobs. I buy parts from their busted engines so I can fix someone elses busted, over boosted, street engines. The rally guys beat the cars really hard, so, everything breaks.
Not a good idea to run an ej engine in aircraft. They are not good for constant 100hp, let alone 150hp.

I could go into detail about how they are built up to 800hp for drag racing, and what happens to the parts when they do, but why waste time on that.
The soobs, or porsche boxer engines can in no way contend with a wankel as a long haul aircraft engine.

Shop your country for a good used RX8 engine and p port it for your aircraft.

Ed Carver


The Rotary Engine News Letter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net.
You Tube http://tinyurl.com/beqqxas.
Copyright 1998-2013 All world wide rights reserved.