|
Ed,
Totally agree with that assessment - extra weight
not good.
Yes the 16X is the answer alright. At the rate I'm
going it will well and truly available and might even be light enough to
use a derated 2 rotor version, but I may be just over
enthusiastic.
George (down under)
----- Original Message -----
Sent: Tuesday, August 25, 2009 10:07
PM
Subject: [FlyRotary] Re: Three or
two?
Well, George, you
will undoubtedly get the stock Mazda turbo to survive a bit longer if you run
low boost – but, then you are lugging around 50 lbs or so all the time for
occasional use.
I think the evidence
is fairly clear based on the number of failures that folks have had trying to
use the stock Mazda turbo. I believe John Slade even had his modified by
a firm down under with fixes that should have (in my opinion) extended its
life and it lasted 11 hours. Certainly the less you stress it the longer
it will probably last – but, I just wouldn’t want one in my aircraft. If
I were then I would get the modifications made that John
did.
However, the great
thing about this hobby is you can take your idea and try it out. I think
in your case you would do best with the one rotor 16X which should give around
120+HP and be much lighter in weight.
Just my
0.02
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of George Lendich
Sent: Monday, August 24, 2009 6:23
PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Three or
two?
I'm no Turbo
expert, but I agree the TO4 with larger AR has been successful at living a
reasonable time.
I also agree
that Mazda placed the Turbo close to the engine to get the most exhaust power
to the Turbo for spontaneous acceleration.
However I would
question if that is in fact what we in Aviation are seeking - I personally
don't believe it is.
I may be
totally wrong in my thinking, but I believe if we use the Turbo for altitude
compensation or Take-off, I would personally separate the turbo from the
exhaust and put in a feeder tube from the exhaust tube, controlled by a
butterfly or valve that can redirect some of the exhaust to the Turbo,
but only when needed. I believe in this way the heat and unnecessary use
of the Turbo will enable it to live much longer.
In this way I
believe we are modifying the flow to the turbo rather than modifying the
turbo in an attempt to live in an environment of continuous use, and as you
suggest, they won't survive a continuous service.
Food for
thought, I hope.
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
>
--
Homepage:
http://www.flyrotary.com/
Archive and UnSub:
http://mail.lancaironline.net:81/lists/flyrotary/List.html
--
Homepage:
http://www.flyrotary.com/
Archive and UnSub:
http://mail.lancaironline.net:81/lists/flyrotary/List.html
-- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
__________ Information from ESET NOD32
Antivirus, version of virus signature database 3267 (20080714)
__________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
__________ Information from
ESET NOD32 Antivirus, version of virus signature database 3267 (20080714)
__________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
|