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I thought you must have done your homework
(research) before laying out that much for the redrive.
My concern is not with the prop/psru/engine weight,
but with the "torque-return-path" to the airframe from the prop.
As Lynn mentioned Rotaries do "interesting" things
when you get that torque to high.
You ARE using a psru, so the return torque is a lot
higher than what the engine dishes out.
The Mistral-"system" is lot more "streamlined",
than your different front(rear-housing) and PSRU.
It should work just fine, though depending how much
power you send through...
I wish I where there, ....to have to worry about
engine-installation...:)
Thomas
----- Original Message -----
Sent: Sunday, February 25, 2007 6:05
PM
Subject: [FlyRotary] Re: motor mount
plate
Thomas,
I really am not overly concerned about the
"Mistral" mount plate
on my stock Mazda 13B......It mounts to my 13B exactly like it does
on the "Mistral" 13B........Another feature of my installation is
the
moment arm of my engine is considerably less because my redrive
is one of Tracy's 2.85 units which weighs less than the "Mistral"
unit.
I was in contact with Francois throughout my 2 year
wait to aquire
the backplate........Thanks for the concern and comments from both
you and Lynn........
--
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold
--------------
Original message from "Thomas y Reina Jakits" <rijakits@cwpanama.net>:
--------------
----- Original Message -----
Sent: Sunday, February 25, 2007 11:07 AM
Subject: Re: [FlyRotary] Re: motor mount plate
Kelly,
maybe you should talk to Francois about your specific
installation, ....again.
He would be the one to answer.
Just looking through their line-up, attached a pics
from the Mistral site.
Pic1shows that their package is very
streamlined/integrated. Website says lots of FE-analyses.
Your package may differ and torsional intergrity may look
different...
Thomas
PS: Pic 1 follows without comment....
----- Original Message -----
Sent: Saturday, February 24, 2007
9:07 PM
Subject: [FlyRotary] Re: motor mount
plate
In a message dated 2/24/2007 7:55:29 P.M. Eastern Standard Time, keltro@att.net writes:
Lynn,
And here I sit with a "Mistral" mount plate residing
where the
stock front cover used to be on my 13B.......It allows the use
of
a standard Lycoming "Dynafocal" mount ring to bolt my
engine
to my "Dyke Delta".....What do you think are the chances of
my
normally aspirated rotary from over-stressing its end-plates
and
rotor housings......."Mistral" does have provisions for using
a
four point bed type mount on the 13B (using their redrive)
and
it is required on their 20B , three rotor
engine ......... Attached
photo is of "Mistral" 13B on a Glasair project of one the
rotary
group, Steve Thomas in Calif.......Hope you do not mind
Steve!!
--
Kelly Troyer
"Dyke
Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold
Francios Had the reduction unit in the motor tent at
Sun & Fun about 5 years ago, looking like a lost puppy. They had
been trying to get the Piper to fly long enough without frying the oil so
they could have it on display at the flight line. No dice. I talked to him
for a very long time. He took notes. They are all engineers, and trust
math to get them out of anything.
So they calculated everything, and on paper there would be enough oil
cooling to do the job.
Well that test location was in Florida before Global warming had died
down. I suggested best power was down around 160 degrees max, and he was
sad. The coolers were big enough. The flow rate was high enough.
Airflow through the coolers was high enough.
The oil temp would just slowly climb into the red 230-240-250 and
land again.
They didn't realize the Mazda pump was designed to work OK at 2,000
crankshaft RPM.
So, at 6,000 RPM it foams the daylights out of the oil. And air in
the oil is an insulator, and the effect is that the coolers get smaller
with time. The oil pump has a front and rear segment and those are shaded
just a bit to reduce noise. Both must pull suction oil from the back end
so the number of sharp corners the oil sees inside the pump is more than a
normal pump.
Plus, the higher flow was unhappy with the tiny bug screen at the end
of a sharp edged tube in the pickup. So, there was a vena contracta
problem. So, they took off the bug screen and it started working
well. They took out the airplane oil and put in car oil Fewer polymers,
and it worked better. They made up a dual pickup casting to feed both ends
of the pump like the FD oil pump and everything is fine.
The point of the story is that the mechanical parts have many actual
hours of flying in a real airplane in hot weather. So, it is thoroughly
test in a real life situation.
Their front Iron and mount is thicker and stiffer than the stock
stuff. There will be no problems.
Lynn E. Hanover
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