|
|
I also have the Dyna ring from my Lancair
Legacy which I believe to be type 2. I live halfway between Orlando
and Daytona Beach,
Fl. If you can find a scanning shop at either location, I will be happy to
take my ring there to get it scanned.
The rubber mounts were something like $115
each at AC Spruce. I sold the set for $200.
Bill B
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Charlie England
Sent: Tuesday, April 26, 2011 6:07
PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: Mistral
'Like' Intake
2nd Kelly's opinion. the info I have said type 2 was
for engines with *extended hub* constant speed prop (~2 1/2" beyond a
normal constant speed), which moves the cg forward a lot. Van's no longer even
supplies type 2 mounts because they are so rare.
IMO, the only reason to do dynafocal at all is because the mounts are so
common. the old 'conical' style mount (4 parallel bolts) would be just fine for
a rotary with its inherently smooth operation. The reason Lyc did the dynafocal
was an attempt to damp their flat 4's horrendous vibration pattern (not that
effective...). The conical mount
Lyc motors can be
converted to dynafocal by an engine shop, implying that the bolt circle is
virtually identical. The downside to dynafocal is that the rubbers cost about a
factor of 10-15 more money than conical mount rubbers. Less than $30 for a set
of conical; $300-$500 for dynafocal.
I still have available the dyna ring off my original RV motor mount, if there's
a scanning shop in Jackson MS. If you can find a shop, let me know & I'll
take it there for a scan.
To address the concern about attachment strength: with a new housing, it should
be relatively simple to add a piece to grab the top of the middle iron or even
the bellhousing flange top bolts if you're really paranoid. I'm no engineer,
but I'd think that there is plenty of bolt & aluminum area to take the
shear loads; the only question in my mind would be the bolts at the top that
will be in tension in the cast iron casting. I have a hard time believing that
6 gs could stretch the 4 or 5 bolts across the top of the 'stack' enough to
affect the engine, at the relatively low power levels that will be used in a/c.
(I'm strictly talking about 2 rotor engines, not the 3+ rotor versions.)
Charlie
On 4/26/2011 9:04 AM, Kelly Troyer wrote:
The "Mistral" 13B
engine (and their 20B) CG of 9.44 and 11.73 inches
respectively was complete with
all accessories and redrive (which is heavier
than Tracy's RD1X
re-drives of 44 lbs)................The addition
of a constant speed (with normal extension) would
still keep the Type 1, 30 degree focal point of 14.373"
in front of the 13B CG (IMHO)...........The 20B CG
with normal constant speed would have to be calculated
to see if it remained within the Type 1, 30 degree
14.373" focal point..............The type 2,18 degree seems
to have been used only on a specific 0-320 model
installed in the twin Comanche (That does not keep your
Lancair from having this engine
installed)..................
Kelly Troyer
"DYKE DELTA JD2" (Eventually)
"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil Manifold
"TURBONETICS"_TO4E50 Turbo
From: H & J
Johnson <hjjohnson@sasktel.net>
To: Rotary
motors in aircraft <flyrotary@lancaironline.net>
Sent: Tue, April 26, 2011 2:36:54
AM
Subject: [FlyRotary] Re: Mistral
'Like' Intake
Interesting. I may very well be wrong but for some reason I had it in my
head [once it was jared by Bills mention of Type 2] that the Type 2's were
usually used for engines w/ constant speed [due to weight] and the type 1's
were used mainly for fixed pitch. [old wives tale?] I would think that due
to our extra weight out front on the nose a Type 2 would be more in order.
Having said that, I have no idea where the CofG on a 13B is located and how
that relates to the various focal points. In addition, how adding a PSRU on the
nose would impact the CofG [and or a electricl pitch prop etc]. I'll have
to do some reading and see what I can dig up. Certainly a good place to
start w/ as far as a ground up design on the mounting housing.
Lynn,
re: Strength of the Connection.
I
remember you stating some of those points a while back. I'm wondering if, in
our lower power state, these are as much a concern as they are in the racing
world? It would certainly be possible to add extra parts to the install [the
thickened bottom plate, or perhaps some form of a stiffener that locks the
block from torque related movement front to back { all just thoughts
flashing through my brain, RHRN}. I've not heard comment about how Mistral
addressed this [or if it was a concern of theirs?].
Kelly,
do you know of any additional connection points [dowels or pins etc] that were
needed for the instal of a Mistral housing?
It
certainly is not my first 'pick' to have a mounting housing which needs
modifications to a short block, to allow it to be installed.
Jarrett Johnson
www.innovention-tech.com
Here is the
source of my "Dynafocal" mount info...............
Kelly Troyer
"DYKE DELTA JD2" (Eventually)
"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil Manifold
"TURBONETICS"_TO4E50 Turbo
From: Kelly
Troyer <keltro@att.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, April 25,
2011 10:37:25 PM
Subject: [FlyRotary] Re:
Mistral 'Like' Intake
My info says the
Type 2 ,18 degree was introduced when O-320's were put in twin Comanches
with extra long constant speed prop extensions (for a
more streamlined cowl)............This then put
the engine CG further forward so to keep the
Dynafocal mount "Focal" point slightly ahead of the
engine CG the Dynafocal mount angle was reduced from
30 degrees to 18 degrees.........
The Dynafocal type 1
focal point is 14.323 inches from the mounts..................The
"Mistral" 13B
engine CG is 9.44 inches from the mount so should
work well with the type 1, 30 degree Dynafocal
Kelly Troyer
"DYKE DELTA JD2" (Eventually)
"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil Manifold
"TURBONETICS"_TO4E50 Turbo
From: Bill
Bradburry <bbradburry@bellsouth.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, April 25,
2011 10:13:02 PM
Subject: [FlyRotary] Re:
Mistral 'Like' Intake
There is also a Type 2 Dynafocal that I
think is in more common usage. If I recall the angle on it is 17 degrees.
Bill B
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
On Behalf Of Kelly
Troyer
Sent: Monday, April
25, 2011 4:57 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re:
Mistral 'Like' Intake
I found the
"Dynafocal" info................Was on my other computer
!!..................
Kelly Troyer
"DYKE DELTA JD2" (Eventually)
"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil Manifold
"TURBONETICS"_TO4E50 Turbo
From: H & J
Johnson <hjjohnson@sasktel.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, April 25,
2011 11:21:48 AM
Subject: [FlyRotary] Re:
Mistral 'Like' Intake
The scanning should give in the tens of thousands
[0.01"] or less depending on what type of equipement used etc.
That in conjunction w/ bolt hold placement that I already have [lots of
collected data over the years] I should be able to duplicate the basic
geometry. From there it will become a new product in that we want to make
it something that works for everyone [or as many as possible] to make
it a viable unit. That info, mixed w/ knowing what the 'Standard' mount
geometry is should get us where we need to go.
Best regards
Jarrett Johnson
www.innovention-tech.com
----- Original
Message -----
From:
Kelly Troyer <keltro@att.net>
Date:
Monday, April 25, 2011 10:03 am
Subject:
[FlyRotary] Re: Mistral 'Like' Intake
> Jarrett,
>
> I do not know exactly what dimensions
the scanning give you
> such as bolt
> hole placement, etc.........I presumed
> that the angles of the mount ears needed for the "Dynafoal"
mounts
> would be
> "Dead" on though..........
>
>
> Kelly Troyer
> "DYKE DELTA JD2" (Eventually)
> "13B ROTARY"_ Engine
> "RWS"_RD1C/EC2/EM2
> "MISTRAL"_Backplate/Oil Manifold
> "TURBONETICS"_TO4E50 Turbo
>
>
>
>
> ________________________________
> From: H & J Johnson <hjjohnson@sasktel.net>
> To: Rotary motors in aircraft <flyrotary@lancaironline.net>
> Sent: Mon, April 25, 2011 10:49:43 AM
> Subject: [FlyRotary] Re: Mistral 'Like' Intake
>
> Excellent, now I just need to get some Dynafocal dimensions [I've
> seen it on
> the web in the past, just gotta re-locate the dimensional
> 'standards']. That in
> conjunction w/ a few scans & the picture will start to really take
> shape!
>
> I love progress :)
> I can't say Thanks enough Kelly, w/out the help of yourself and
> others it would
> be a much steeper curve to get it up to speed.
>
> Jarrett Johnson
> www.innovention-tech.com
> -- Homepage: http://www.flyrotary.com/
Archive and UnSub:
> http://mail.lancaironline.net:81/lists/flyrotary/List.html
>
--
|
|