REFLECTOR: Engine Selection

[Alex Balic]

Nice installation Al !
  -----Original Message-----
  From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org]On
Behalf Of Al Gietzen
  Sent: Wednesday, June 16, 2004 10:12 AM
  To: 'Velocity Aircraft Owners and Builders list'
  Subject: RE: REFLECTOR: Engine Selection






  Subject: REFLECTOR: Engine Selection



  I am quickly approaching a point where I have to make a decision on engine
selection.  My current leaning is towards a Rotary, 20B.  To those who have
taken the auto conversion route, I ask if you had it to do over again would
you have made the same decision?  Would you opt for a firewall forward
package or build the engine accessories yourself?  On a 20B does anyone have
a good idea of what the total cost will run to build and install?  Atkins
Rotary is the only one I have found so far that will supply a firewall
forward package (less mount, radiators, prop) his price for a 20B is 20K,
sounds high to me but how does that compare with all the incidentals that
come with building your own?



  All opinions are appreciated.

  Joe



  Engine selection can be a tough decision, mostly because aircraft engines
have not evolved much in performance or reliability, and a good firewall
back installation of more advanced engine technology with good performance
and reliability isn't yet available (in my opinion).  As you may know, I am
in the final stages of a 20B installation on a Velocity SE RG.  I have
answered these questions before, so this may be repetitive; and if you wish
to contact me directly, I'd be happy to discuss further with you.



  Would I do it again?  There have been moments when I may have said no,
usually in moments of frustration.  But deeper down, I know I would have to
make the same decision again for the same reasons.

  I agree with Kurt's comments about it taking innovation, engineering,
patience; etc.  My background as a "knuckle buster" on my own vehicles since
a teenager, and in engineering and physics were factors in my decision.



  There is no firewall forward (backward) package for a 20B.  I got my
rebuilt engine from Atkins, and a few custom parts.  Anything beyond the
basic engine was a nightmare.  He is a good mechanic and knows all about the
mazda rotaries and the parts they use, but that's it.  I'm satisfied with
his work on the engine; however he used the lower compression turbo rotors
in a normally aspirated engine (which is fine if you want to run over 6000
rpm), put on a front pulley with incorrect timing marks, a few other things
that may be good for a dragster, but not necessarily advantageous to an
aircraft.  Either get your own engine to rebuild, or get one from Bruce
Turrentine.  Or, consider a 220 hp Powersport - the closest thing to a
complete package.  And you can also consider the new renesis engine with a
2.85 reduction which will give you at least 230 hp and about 100# less
weight than a 20B.  If I were starting over, that's probably what I would
do.



  I have done a fairly high level of customization on my installation in
order to get good performance without turbocharging, minimize the weight,
and make a clean installation.  I've spent about $22K, including $1100 on
dynometer testing.  I'm sure it could be done for about $15K if you don't
mind some extra weight, maybe less compact or a little more drag.  And, of
course, service and overall later will be dirt cheap compared to a certified
aircraft engine.



  My engine runs smooth and delivers a solid 265 hp at the max design prop
speed of 2900 (6300 engine shaft, 2100 rotors).  The dyno report is at
http://members.cox.net/alg3/Dynamometer%20test%20report.htm, and engine
installation photos at http://members.cox.net/alg3/ROTARY%20ENGINE.htm. The
complete package weighs 425#, including coolant (no prop) - probably pretty
close to an all-up Franklin installation.  It is a simple, reliable engine
with complete redundancy in the electronic ignition and fuel injection.  If
I have done a good job on the ancillary systems, it should be a reliable
package.



  Best of luck,



  Al
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