REFLECTOR:Considering alternate engines

Sat, 19 Apr 2003 11:30:38 -0500

Dale,

I completely agree.  I hope the Renesis becomes available. My comments are
somewhat limited by what is actually available now. But, as most things in
aviation, it is a compromise.  More power and ability to fly higher (if you
want to) as a trade off for more complexity and weight (about 30lbs, I
think).

I think it is relative.  The three moving parts on the 13b is simple, but
even with the turbo, it still should be more simple and reliable than a
piston engine.   I personally do not think this additional complexity
offsets the benefits.  Any more so the reduction drive complexity is a deal
breaker (but it does add complexity).  I will strive for as simple a design
as my desires/needs allow.  A turbo is simple, but due to the extremely high
temps and RPM's is somewhat more prone to failure. It has only one moving
part, of course it is moving around bearings.  One of the complaints of the
rotary is the noise.  The turbo reduces the noise and puts the exhaust to
good use.  The high exhaust temps of the rotary trash normal metal mufflers.
Stainless steel helps (also inconel...I don't know anything about inconel
though), but a turbo can replace the muffler.

>From what I understand, as often is the case with piston engines, many
failures are due to supporting systems such as the alternator, etc.  You do
not have to have an alternator, but if you don't want to hand prop, etc, it
is handy.  I want the extra power if needed.  Again, hopefully, with my
current knowledge, available with a Renesis.

My readings say the Renesis is the same size as the other 13b's (I can't
believe how small the core I bought Friday is), but is lighter and more
powerful due to better technology. For example, the older 13b's did not vent
all of the exhaust gases before the intake stroke began. The Renesis has
been improved that the exhaust gas is gone before the intake begins, and
from what I understand, this add power.  Thus even though the weight to
power ratio on the original 13b's is impressive, the Renesis is even more
so.  With some work all these options should weigh about the same or even
less then a Lyc 360. I wish the RX-8 was a car with wider appeal (I don't
think it will do well, IMHO) This would make the Renesis more available.

Velocity Inc, says I do not need this much power for the SE, but it is nice
to know 250 hp is there if I want. Velocity Inc, states that 200hp should
give me about 200 mph cruise with fixed gear.  So a constant 200 hp would be
sweet.  The Renesis should provide this without taxing the engine too
much...so should a turbo.  The N/A 13b will work too, but not at a constant
200hp.....it would be 200hp for take off or other full out operation.  The
SUV was advertised to use a 160hp (320 Lycosaurous) engine, so it would seem
all these options are useable.

This is one of the benefits, IMHO, of the Rotary.  Options (esp. in
comparison to price of these options).  The N/A version can be modified
reliable to about 200hp max with some minor effort (also, a turbo can be
added).  The turbo, may give 250 hp.  The 20b three rotor with four moving
parts may provide 250 hp N/A or 300 hp turbo, but is heavier and longer and
a little more complex. Heck, some 13b's have been modified for race use to
something like 800 hp, but reliability drops big time <g>.

To me, it is great that all this is available at a MUCH better price than a
certified a/c engine.  For a do it yourself rebuild, parts are abut $900.  A
professional rebuild is $4000 for aviation use. The Renesis is reported to
be about $6500.00 new. Heck, at this price I can almost have an extra engine
sitting around to use if I need it <g>.

FWIW.

All the best,

Chris

-----Original Message-----
From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On
Behalf Of Dale W. Thomas
Sent: Saturday, April 19, 2003 9:53 AM
To: reflector@tvbf.org
Subject: RE: REFLECTOR:Considering alternate engines

Chris,
  Just curious....
  My thinking is that one of the biggest benefits of the Mazda rotary was
the reliability inherent in a design with only 3 or 4 moving parts.
Adding a turbo would seem to be adding complexity into the package that
could offset the benefits inherent in the design.
  Then when you look at the fact that there is (or soon will be) available
a NA version which will give you pretty much the same power as the more
complex smaller version, it makes me wonder why one would choose the
small turbo over the larger NA.
  What am I missing?

Dale
PS.  Thanks for the links....
PPS.  When you post a link, if you include the 'http://' in front of it,
it should come across in most email clients as being a clickable link
right in the email.  Something like....  http://www.LoneStarVelocity.com

> Al is further along than me. Also, he is using the bigger and heavier
> 20b. I plan on using the 13b. I should be able to get pretty good hp and
> even approach the same power of the 3 rotor 20b NA (normal aspiration)
> if I turbo the 13b.  Mazda has just introduced a new 13b which is rated
> at about 240 hp before you sip off the emission stuff.  It is called the
> Renesis and is only available in the new RX-8. New, out of the box it
> may cost about $6500.  A guy in Australia says he can get them now, but
> they are not available in the US yet.  Hopefully before I need one for
> my SE, they will be available.
>
> I bought a 13b core yesterday for $100.00 so I could strip it down and
> play/learn from it.  You can get a rebuilt 13b (which, btw is all new
> parts) for aviation use for about $4k.  There is a very good video
> available on rebuilding the rotary.  Cost for a complete overall is
> about $900, if you do the work.  The smaller 13b should be able to
> produce from about 160 hp to 210 hp NA or about 250 turbo.  The 20b
> about 250 NA.  There are only three moving parts in the 13b and I think
> 4 moving parts in the 20b.  Of course this does not include accessories
> such as the alternator.  I really like this option.  Rob Johnson, a
> former Velo builder/owner was going to use a 20b in his XL, but decided
> on a Lycosarus for an easier/know
> installation....but, Rob is a fan of the Rotary and has a nice
> commentary on his Velo builders page at www.robjohnson.com.  Finally, if
> you go to the links page on my website, www.LoneStarVelocity.com ,you
> will find most of the really good links for rotaries in aviation use.
> Be sure to visit Tracy Crooks company site, Real World Solutions at
> www.rotaryaviation.com.  Tracy has 1300 hrs on his RV and sells ECU and
> reduction drives.  I got my engine mount for www.conversionconcepts.com.
>  Nice work.
>
> Please feel free to give me a call if you want to discuss it more.  Home
> is 713-991-0333, Office is 281-464-5297 and cell is 832-818-2355.  Or
> email, you know the address <g>.
>
> All the best,
>
> Chris

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