> > > > Hello Paul,
> > > >
> > > > I'm searching for a RV-4 renesis engine mount.
> > > >
> > > > Jerry told me you would do the engineering and he would do
> > the
> > welding.
> > > >
> > > > As I remember you will need the firewall hardpoint plan sets
> > > > which I don`t have because I decided to start firewall
> > forward
> > > > for different reasons.
> > > >
> > > > I remember seeing some pics of a RV-4 mount on your
homepage,
> > > > so I hope you already got the needed plans?
> > > >
> > > > best regards
> > > > Thomas
> > > >
> > > > Sure no problem. I need a few dimensions. The firewall out
> > line
> > > > and the lenght of the cowl. Also do you plane to use the
> > stock
> > > > checked cowl or build you own? I think I know where you
> > > > can get a real slick rotary engine cowl from Brian Trubee.
> > > > Brian might also give us the hard point dimensions. I might
> > > > have them as well.
> > > >
> > > > --
> > > > Paul Lamar ...No rotor no motor.
> > >
> > >
> > >
> > > Cool!
> > >
> > > I don`t want to use the stock cowling.
> > > Something like Mike Wills or Brian Trubee, if possilbe with
> > a ram air
> > > scoop. But thats far away in the future yet.
> > >
> > > Is Brain still onboard?
> > >
> > > Kind regards
> > > Thomas
> > >
> > >
> > > Yes he is. He moved the cooling rad down under the cockpit
> > somewhat
> > > like the quick and simple cooling system. Frees up a lot of
> > volume
> > > under the cowl. Does away with the scoop under the prop. Makes
> > > the cowl easier to build. The last shots are of Steve Rosine
> > > airplane.
> > >
> > > Paul Lamar
> >
> >
> > Hi Paul,
> > I can't put the rad under the cockpit. I think I have to reserve
> > this space for a big muffler. I suppose noise regulations are
> > quite
> > stricter here as in the US. With a RV-4 the benchmark in
> > Germany is
> > around 63 db(A).
> >
> > If I plan to make a custom cowling, do you still need the
> > length of
> > the cowling? I thought the dimensions of the cowling will be
> > defined
> > by the design of the mount?
> >
> > Kind regards
> > Thomas
> >
> >
> > Ah yes. They will probably make you run a three blade prop
> > too. OK back under the cowl with the rad. It is going to look
> > more like a P40 than an Me109 :) (Bf109 ?)
> >
> > Paul Lamar ...No rotor no motor.
> >
> > I changed a few things on my aircraft- made the firewall 1 inch
> > taller,
> > and placed the prop flange 44 inches in front of the firewall,
instead
> > of the stock 39 inches. Also used .025 thick elevator skins and
the
> > extruded trailing edges for the h stab. We'll see how the
weight and
> > balance comes out- I can always change the battery position.
> >
> > I don't know what provisions are made for engine mounting on the
> > renesis, but I imagine that it is similar to the generation 3,
in
> > which
> > case you can use a shertz beam type mount.
> >
> > Brian Trubee
> >
> > Yes that is what I did. Use a Schertz Beam. Here is a 3D Thomas.
> > P-port. Exhaust pipes not shown yet.
> >
> > Paul Lamar
>
> Re Brian's moving the prop out to 44 inches, I think this usually
a
> good idea in that extra space between the firewall and engine is
> very useful. Also, a p ported 13B , properly installed, will be
> lighter than the 0-320 it replaces. I am going to rebuild my
> Tailwind engine mount (again, sigh) and I am going to move the
prop
> flange out to 42 inches from 38 inches. CG can be fine tuned with
> battery placement.
> Jerry
>
>
> OK here it is at 44 inches.
> --
> Paul Lamar ...No rotor no motor.
>
Hi Paul,
Wonderful job. Thank you.
Did you design the mount for the standard firewall (29,13) or the
1 inch taller one like Brian did?
Is this a necessary issue, or was it just for a more comfort
installation?
I wouldn't dare to P-port my renesis.
I prefer side-ports like Tracy did.
For the RV-4 I don't have to squeeze every PS out of the
renesis I could, even If you could have enough power like
you used to say :)
Kind regards
Thomas
Just don't fly over the Alps :) You will need that extra p-port
power at 14,000 feet 5000 meters. Tracy lives at or below sea level
:)
--
Paul Lamar ...No rotor no motor.
I used a partial mount made by Bruce at Custom components in Tacoma,
Washington.($200 in 1999) He makes the complete mounts for Van's. I took
that partial mount and fabricated the rest the same way Tracy Crook did-
by bolting the partial mount to a mockup firewall that is
horizontal/level on the ground. Fix the firewall on the floor with a
couple of dabs of liquid nail, to keep it from moving. Then suspend the
engine with an engine hoist over the firewall mockup. Drill a 1/8 hole
into the bolt on the main pulley on the (automotive) front end of the
e-shaft. Then put a cleco into the hole and suspend a plumb bob from
it. Bolt a couple of 1"box sections to the flywheel side of the engine,
through the bell housing flange bolt holes. Then, when the engine is
situated so that the plumb bob is over the thrust line mark on the
firewall(12 inches from the top on a stock firewall, on the center line)
and the flywheel is level in two directions, weld some braces from the
box sections to the floor, so that the engine is positioned and fixed
in the correct relation to the partial mount. From there, you need to
have triangulated braces from the partial mount to each of your engine
mount points on the engine. I replaced the rubber part of the Lord
mounts with stacks of washers for purposes of welding. I hope this
explanation is fairly clear.
I cut off the top of my firewall flush with the top angle aluminum piece
that goes between the top two firewall mount points. Then I riveted on a
new piece that was 1" taller than the piece that I cut off.
If I were to make another cowl, I'd plot out profiles of the cowl at 2"
intervals from the firewall all the way out to the prop flange.(Paul,
you sent me co-ordinates for that once) Then I'd cut out those profiles
>from 2"foam, and glue and stack them up. Then sand them to get a smooth
profile, give a coat of drywall joint compound, and lay up my fiberglass
over that.
I hope that these explanations are clear, if not, let me know and I'll
try to clarify.
Brian Trubee
Thanks for the explanations about the cowling.
Thats the way I would do, too.
There are whole planes built like that.
http://www.waraircraftreplicas.com/
Kind regards
Thomas
The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site.
http://www.rotaryeng.net
Copyright 1998-2006 All world wide rights reserved.