> It weighed too much for three reasons. The pattern was made
by hand
> and it
> is near impossible to make a large pattern with .1875" consistent
wall
> thickness
> by hand even if you are a HIGHLY skilled pattern maker. I
know I have
> made some
> intake manifold patterns. An accurate pattern made on a NC mill
> profoundly changes all that.
>
> The second factor is what can the foundry do in terms of
minimum wall
> thickness? American International in San Fernando California
has no
> problem with that as I have seen hundreds of parts in their
foundry.
>
> The third factor was the incorporation of motor mounts in the
bell
> housing.
> That idea has fallen into dis favor as the preferred method of
engine
> mounting is the Schertz beam.
>
> The projected weight of this bell housing, as cast, is one pound
lighter
> than your set up despite a conservative wall thickness of .2
inches.
> That is before NC machining where more weight can be removed.
>
> As far as the load is concerned we have already done some static
> testing thanks
> to Jerry Hey. We will do the same kind of static testing on
the new
> bell housing
> as well as an FEA.
>
> Not many new designs are mounting the starter at 6 O'clock as it
> precludes using one large rad under the engine which
simplifies the
> cooling plumbing and the ducting. Mounting the starter at six
O-clock
> allows a
> simplification of the bell housing and a reduction in its
weight and
> cost.
>
> Paul Lamar ...No rotor no motor.
>
> Opss correction.
>
> That should be: "Mounting the starter at nine O-clock allows a
> simplification of the bell housing and a reduction in its
weight and
> cost."
>
I don't really understand your comment about the starter at 6
o'clock
precluding positioning the rad under the engine.
That is the configuration I have. In my pusher config, the rad
is below
and forward of the starter. In the future, to lower drag, I
would like
to position it even farther forward.
In the photos on this page, that you took at Arlington last
year, you
can see the starter bump in the cowl is way above the rad. The
rad is
forced to that low position by the oil pan, not the starter. You can
also see my concept 3D drawing, where I would like to position
the rad
farther forward.
http://www.bridgingworlds.com/LEZ13B/LEZ13B.htm
Perry
I was speaking of a tractor installation Perry where the air comes
in over
the top of the rad to keep it cool. Your cowling is so tight I
think you
would have a bump where ever you put the starter.
If you still have Rhino working send me an IGES zipped of the
last 3D
and I will do some scale transparent renderings with the starter in
various positions.
Paul Lamar ...No rotor no motor.
Paul,
My installation shows why the starter had to be relocated. The nose
gear is integrated into the motor mount, and is near the front of the
mount. There are gear supports behind the nose strut that prevent the
radiator from fitting there. Moving the starter to the 9 o'clock
position freed up just enough space to fit the radiator in front of the
nose strut.
Mark St.
You did a beautiful job Mark. Your airplane is right up there with
Bulent's
and Al Gietzen's. All three of you guys could win the Sun & Fun best
auto engine
award if you choose to fly in there some year.
BTW Larry tells me the new bell housing pattern will be done in
about a week.
We should have some pictures then.
Paul Lamar ...No rotor no motor.
Thanks Paul, that is very kind of you to say. My goal all along has
been to make my rotary installation comparable to, if not better than, a
certified installation.
Mark St.
Yours is particular simple which is very good. There is room up
there for a luggage compartment :)
Paul Lamar ...No rotor no motor.
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