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The stock Mazda Turbo really should not, I
repeat NOT, be used in aircraft application. A number of folks have proven
this conclusively. Now IF you run low boost for a limited amount of time you
may be OK – a few folks have
done this, but I really wouldn’t chance it. The auto turbo was designed
to deliver perhaps 8- 10 psi of boost for 30-60 seconds to give you that sports
car kick in the seat of the pants. The turbine housing on the stock Mazda
turbo is way too small for our application and will cause the turbine to
overspeed destroying the turbine and bearings.
On the other hand, using the correct turbo
such as the T04 with a larger A/R ratio will (as several have shown) making a
reliable turbocharged application. I have two Mazda Turbos sitting on my work
bench, but realized after I got them that they were just not suited for
aircraft application. You really want the turbo as close to the exhaust as
possible to take advantage of the heat energy of the exhaust. In fact, Mazda
attached them right to the exhaust manifold – its not the heat that quickly
kills the stock turbo in aircraft us, its primarily the unsuitability of the
turbine housing and the fact they were never designed to run hour after hour
under boost.
I believe there is a firm down under that
will modify the stock Mazda turbo enlarging the A/R ratio and installing a
different compressor – but, in my opinion, you are probably better off to
invest in a turbo designed for this kind of application.
Since I don’t use max power, except
for take off, I have come to the conclusion that a turbo just wouldn’t
buy me much except extra weight – me?, I’m waiting for the 16X
{:>)
Ed
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of George Lendich
Sent: Monday, August 24, 2009 2:21
AM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: Three or
two?
I should have said all 13B turbo's have low
compression rotors at manufacture. I did mention Turbo used for
normalization,( should have said, using higher compression rotors). It
is a bit of risky business if not watched carefully IMHO.
Do I remember Leon Promet - sadly I do, I personally
wouldn't be calling him a trusted rotary expert, and I know him. He does
however know a lot of knowledgeable people in the rotary rebuilding industry,
I've met some of those as well.
I think the proof has been they have to be heavily
modified for Aviation use to keep from overspinning in thinner air. That's my
understanding from watching the chaps who have regularly replaced their turbo.
I personally believe that keeping the turbo as far
from the exhaust manifold and restricting flow to the turbo is the only sure
fire way of keeping them alive for any period of time - in Aviation use.
>All turbo 13B's require low
compression rotors.
Not quite true, George. On the advice of two trusted rotary experts (one of
whom was Leon Promet - remember him?), mine has the 9.7 rotors and 3mm seals. Leon said this
just gets you a free 30HP so long as you don't overboost and you keep the
timing & mixture in range. I don't have any detonation problems boosting to
42 MAP with the IVO prop. I did notice some detonation / pre-ignition noises
early on when running up with a fixed pitch prop. These went away immediately
on throttle back and didn't do any engine damage.
John Slade
George Lendich wrote:
I don't know if the Renesis has a turbo version, I
didn't think it did. All turbo 13B's require low compression rotors.
You can put Renesis rotors into RX7's but not the
other way around. The RX8 rotors are a high compression rotor, higher than Rx7
rotors, the RX8 (Renesis) are 10:1 compression.
I guess you could use a turbo for altitude
normalizing, but great care would have to used, I can't say I would recommend
it.
Consider peripheral ported RX7 engine with 44mm
inlets.
In Chile there are
only a few Rotaries. Mazda sell a lot of cars here, but not too many rotaries,
and there are no enthusiasts of the wankel engine, so for support and
parts, I’ll have to go to the U.S. anyway.
If I
chose and engine, a two rotor, which way do you think is better, the 2004
renesis for example (I saw one in eBay) or the 89-91 or 93-95 as you said? Can
the “modern” renesis be use with a turbo?
Thanks
Gonzalo.
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
On Behalf Of William Wilson
Sent: Domingo, 23 de Agosto de
2009 1:29
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: Three or
two?
With only a
couple of exceptions the two- and three- rotor engines take the same
parts. Only the "big" center housing and the eccentric shaft
are really special for the 3-rotor engine. Luckily, these don't usually
need to be replaced. Of course, the manifolds, fuel injection and most of
the electronics are unique but you won't use the stock parts anyway. Most
everything else is either the same as, or interchangeable with, the '89-'91 or
'93-'95 13B turbo.
Which, of course, brings up the question of whether or not you can get *those*
parts. There is plenty of support in the U.S. for rotary engines, since
Mazda sold lots of RX cars and tuners are used to bringing in Japan-market
parts. Is there such support in Chile? It is tough enough to
build a plane without having to build your own engine too.
2009/8/22 Gonzalo A. Giménez Celis <gonza@gimenez.cl>
Well, actually is not that bad. There are a couple of
runways 3000 ft long,
and others 2000 ft. Altitudes varies from sea level up to 7500 ft, but I
don't plan to go there often, and if I do, the runway is very long. I want
to have a little more power just in case. I think the 200 HP is enough,
right?
Also, what about the parts, it seems that the two rotor parts are much more
available than for the 20B...
Thanks!!
Gonzalo
Behalf Of Dave
Sent: Sábado, 22 de Agosto de 2009 17:08
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Three or two?
While I am in favor of the rotary, it is worth saying that none of the
very few currently flying turbo rotaries have had trouble free
installations.
I know of John Slade and Dave Leonard, and both have had more than one
turbo failure in the process of finding what works.
I do not know if Mistral is currently selling its turbo version.
What sort of runway length and density altitude are we talking about,
where you intend to operate?
Dave
Thomas Mann wrote:
>
> A two rotor engine produce close to 200 hp at 291 LBS (132 KGS)
>
> A two rotor with turbo can produce 230 hp at 328 LBS (149 KGS)
>
> A three rotor engine can produce 300hp at 390 LBS (177 KGS)
>
> *From:* Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net]
> *On Behalf Of *Gonzalo A. Giménez Celis
> *Sent:* Saturday, August 22, 2009 3:05 PM
> *To:* Rotary motors in aircraft
> *Subject:* [FlyRotary] Three or two?
>
> Hi group. As I told in previous questions, I’m building a Cozy MK IV,
> and I like the Rotary idea. I would like to have between 200 and 250
> HP, since in Chile we
don’t have such long runways like in the U.S.
> and is a pretty mountainous country. Regarding this, which way is
> better, a three or two rotor engine? Is the three rotor too heavy? Can
> I use a turbo in a two rotor engine without affecting reliability and
> weight? Etc…
>
> Thanks.
>
> Gonzalo
>
> Chile
>
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