Jarrett,
I'd definitely be interested in a new intake for mine at some point down
the road, if:
1) Its affordable (and $2100 isnt even in the ballpark).
2) Its compact; I dont have a lot of room under the cowl.
3) Its light. I dont think you will accomplish that with a completely cast
manifold.
For a point of reference my engine is an 89 4 port. I'm not certain but
would be willing to bet that for aircraft use this is still the most common
configuration in use (and consequently likely the largest market). Tracy might
have some input on that.
I used a 6 port bottom manifold casting as a starting point and ground off
all of the water/exhaust jacketing to save weight. I used JB Weld putty to fill
in the gaps and blend the manifold to the 4 ports.
For the upper manifold I used the 90 degree turn portion of the upper and
cut the rest off with a bandsaw. I then welded aluminum tubing and some sheet to
finish out the runners and the dynamic chamber/throttle body mount. Again
liberal amounts of JB Weld was used to blend things.
I made injector bosses and welded them to the outer runners. Used the stock
center housing bosses for the other two injectors.
I didnt weigh it, but it's pretty light. No way you could make one from a
casting that would be as light.
To me the ideal intake wouldnt be a casting at
all. It would be made entirely of aluminum U bend tubing welded to a
1/2" flange. This would be light, smooth, clean, and pretty. I used to have some
pictures of a manifold like this but cant seem to locate them. There is a guy in
the local EAA chapter that wanted to go into business building rotaries for
aircraft back in the early 90s. He commissioned Racing Beat to build the engine.
I dont know who built the intake or exhaust. It was dry sumped. The goal
was to make it as compact as possible and the complete engine minus cooling
system fit in a 18" tube. It was a thing of beauty. RB used to have a picture of
it on their catalog cover.
Why would I change mine? I have nightmares about a big hunk of JB Weld
coming loose and being ingested. For cowl clearance I'd shorten the runners up a
bit and mount the TB on the back of the plenum (and I'm guessing I might
sacrfice some HP in the process based on theory but it would be worth it to me).
Also it's not the most beautiful thing in the world. Anyway, that's my input.
Here's what mine looks like:
Mike Wills
RV-4 N144MW
----- Original Message -----
Sent: Friday, June 20, 2008 8:03 PM
Subject: [FlyRotary] Re: Mistral/ Intake
manifolds
Your right, it was for the 13B... so linearly scaled, the 20B was
$1200?? j/k, you could be right about what it
cost.. :)
Jarrett
> I stand corrected, although I think that $800 may have been for a
> 13B. Looking forward to seeing your design.
> Greg
> ----- Original Message -----
> From: H & J
Johnson
> To: Rotary motors in aircraft
> Sent:
Friday, June 20, 2008 5:09 PM
> Subject: [FlyRotary] Re: Mistral/
Intake manifolds
>
>
>
>
>
>
Greg, currently it's a work in progress, once I get the design
> to
where I think it has leg's I'll post more info. It will be a
> wrap
over design w/ the trottle body/carb on the plug side.
>
>
Last I'd heard Mistral was selling [when they did] their intakes
> for
~$800. If you built an engine for less than that.. please
> dish
:D It's not cheap but then investment castings and machining
>
etc.. generally aren't..
>
>
>
> We'll see
how it goes..
>
>
>
> Jarrett [website is
90% done.. 90% to go... still..]
>
>
>
>
>
> > You're right on that Jarrett, but I think each
installation
> would
> > be different. I know
mine was. Clearances, heat, cowling,
> > horsepower
requirements, flow bench testing, and a bunch of
> other
>
> details about driving me nuts getting mine designed and
>
> fabricated, and I'm still not quite there. If you've got a
>
design
> > that you feel works, how about letting us all in on
it, then
> we
> > can judge, especially when it comes
to cost. Mistral's I
> heard
> > was beautiful,
but costly, probably more than I spent for the
> > entire
engine, and as I said, no response from them, so I will
> >
probably never know.
> > Greg
> > -----
Original Message -----
> > From: H & J Johnson
> > To: Rotary motors in aircraft
>
> Sent: Friday, June 20, 2008 4:06 PM
> >
Subject: [FlyRotary] Re: Mistral/ Intake manifolds
> >
> >
> >
> >
>
>
> > Greg this is why I've been interested in
getting my own
> design
> >
> >
into production. It's an area which most DIY's could really
> use
> >
> > some help.. as far as I can see
it..
> >
> >
> >
> > Jarrett
> >
> >
> >
> > > If you knew what I have
been going through getting a turbo
> > > manifold for
a 20B built, you wouldn't even try. I tried
> >
> communicating with Mistral several times about one of their
> > > manifolds, there was no interest in helping me
out.
> > > Greg Ward
> > >
Lancair 20B in progress
> > > ----- Original
Message -----
> > > From: H & J Johnson
> > > To: Rotary motors in aircraft
> > > Sent: Friday, June 20, 2008 7:51 AM
> > > Subject: [FlyRotary] Mistral/ Intake
manifolds
> > >
> > >
> > > Just thought I'd ask around. A few people
purchased intake
> > > manifolds from Mistral and I'm
trying to find out a few
> things
> > > about
them.
> > >
> > >
First of all, what versions of the 13B did they fit? How
> much
> > do
> > > they weigh? Originally,
what were they selling them for.
> > >
>
> >
> > >
> >
> As I understand it, they no longer sell them to joe-
>
public,
> > nor
> > > do the new
unit's fit on the standard 13B? Are there
> builders
>
> out
> > > there who would prefer to buy a ready
to install manifold
> for
> > > their
projects?
> > >
> > >
> > >
> > > Thanks
guy's!
> > >
> > >
Jarrett Johnson
> > >
> > >
> > >
> > >
>
> > --
> > >
> >
> 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
--
Homepage: http://www.flyrotary.com/
Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html