Paul and Petri,

As an LSA builder wishing to max out the performance envelop we need a
light rotary engine/PSRU combination with at least 140hp.

Underkill for a twin rotor 13b, but just what we need if weight can be
under 200 lbs wet with all system components.  I talked with Tracy about
a lighter PSRU. He said it should be possible to shave off at least 10
lbs but would require a new design, most likely with a C4 gearset.  How
about Autoflight universal gearbox at 9kg + starter and belhousing? This
unit is rated to 150hp wth a larger unit up to 300hp.

There has been more mention of an all aluminum block design.  Is this
reality or still unproven?  It appears Rotamax is the most recent
company to have coating problems with aluminum components or design of
air cooled rotors, and we can't afford failures!!

At this point it appears that we will be building engines of some sort
for our design.  (hoped for Subaru vendor just priced himself out of our
range) and the other rotary company (Canada) is not up to speed yet. So
- an aluminum 13b appears to be the best option for now.

Regards,

Dan F

American Patriot Aircraft

Hello Dan,

Steve Beckman has exactly what you need.
The "Iron Eagle" with furnace-braced steel housings AFAIK weighed about
the same as their "Superlight", ie. 167 lbs installed.

Rotary list, 27. Feb 2008:
"Meanwhile, Francis Romig is the master machinist who did all our
machining on the orignal engines and he is working with me and Phillip
Groelz to build a clone engine to use this reduction gear and engine
mount.  Don Rivera has the reproduction plenum presently for flow
testing and we'll use Don's dual electric pump package."

Don't know how's the progress. Paul has Steve's email address, ask.

Cheers,

Petri

Petri--your reference to the weight of our engines requires some minor
clarification.  The clone engine we built recently of the original
Powersport Mazda conversion engine (1995-97) is not a SuperLight
variant--with neither the aluminum housings or furnace brazed steel housings
used on the SuperLight engines. One of the design goals of the conversion
engine was to keep down costs by using as many Mazda-based parts as
possible.  That is why modified Mazda iron end housings were/are used and
the weight of the engine reflects that fact.

The original Iron Eagle conversion engine was 268 pounds in the
configuration shown in  the side-by-side photos distributed earlier with
theSuperLight.

This weight included  the internal spur reduction gear and
ignition/starter/alternator.  It did not include induction and fuel systems,
or port inserts.   The estimated installed weight full up for the new engine
will be heavier than the original due to two factors:  the current reduction
gear is significantly stronger but heaver than the original prototype
reduction gear.  Also, back then we usually did not run a muffler with the
original Iron Eagle; relying on the stock Mazda port inserts and a 7"
insulated exhaust augmentor which we had installed in tunnel fabricated
through a specially fabricated engine mount and floor of the RV-4.  A tunnel
for this terminated at the front of the spar.

We measured the sound levels of engines with and without the Mazda port
inserts and it was surprising how well they worked.  Somebody in the Mazda
tech center really earned their paycheck when they developed these.  But
even then, these normally aspirated engines need an effective, lightweight
muffler to produce the sound quality they deserve.  We did flight test a
large volume, low back pressure chambered muffler with the Superlight engine
installed in the first RV-3 and it made a nice pleasing sound with minimal
penalty..  But we had much more room for it with that little engine which
was mounted so far forward.  Am working currently to mock up a muffler in
the reduced space in the RV-3 with the Mazda conversion clone.  The plan is
to build a lightweight muffler for dyno tests.  Following those tests we'll
weigh the engine full-up when it is installed in the aircraft and report
back with some photos.  But the final installation weight, with all
accessories, will be heavier due to the above factors.

Steve Beckham