George Lendich wrote:
Paul,
I have come up with this idea and want to run it by you.
I like the flat plate (between oil pan and housing) idea for engine
mounting.
I understand the problems with oil leaks and the double seal problem.
Although not immediately, I've decided to try and design a one piece
plate and oil pan with
mounting points, and have it molded with reinforcing ribs (probably
externally) through the pan to
make it more rigid.
The mounting points will most probably be some bolt on arrangement -
to keep the initial mould as
simple as possible.
My questions is - do you see any major problems with this idea ?
What in your opinion, would be the most suitable shape.
How wide do you suggest the mount points should be apart?
Should I go for 4 mount points (on the sides) on the plate or 2
forward and one centre rear?
Perhaps some consideration could be made for bell housing attachment
points!?
Any other suggestions - from anyone
TIA
George (down under)
If it is designed right other than the sealing and weight problem it
could work.
The wider apart the mounts are the softer they can be for better
vibration isolation. that is why mine are 29 inches center to center.
that was the max width I could still get in my cowl. My goal is a
Cadilac like
ride :) The Questair Venture uses this idea and if you talk to someone
who has flown one they will say it is the smoothest piston powered
airplane they
have every flown.
Use two mounts under the engine/PSRU/prop CG and one in the center rear.
Paul Lamar
Just when I thought I was getting my choices for engine mounting
narrowed down, someone comes up with another alternative. My main concern
with Jerry's solution is the width although I like it otherwise. The
firewall mounting points on a LongEZ are close together because of the
narrow fuselage. I don't think it is a good idea to have the mounting points
on the engine end wider than those on the firewall. I have been looking at
the Fred Breese sandwich mounting system (Conversion Concepts) which I think
is a take-off from what Tracy Crook uses in the RV/Otter. Does anyone have
any experience indicating whether there has actually been any oil leakage
problems with the double seal?
George, if you go ahead with your design, could you provide alternative
widths for the main attach points? Wide for the wide cowlings and improved
vibration charactaristics, and narrow for those of us that don't have any
choice but to be narrow. I like the one-piece idea. How soon do you think
something will be ready?
Dick Gregory
LongEZ N613NC
Perry Mick has come up with a good narrow Long EZ design.
The rectangular tubing circumvents the close vertical proximity of the
motor
mounts on a Long and feeds the loads into the landing gear area
as that is where they end up anyway.
Paul Lamar
Dick,
Sorry to be such a fly in the ointment -so to speak!
This idea is to help with some 12A installs into an Aussie Kit Aircraft.
So I will do the 12A first, which is 200 mm shorter than the 13B.
So if your in a hurry, I wouldn't wait if I were you.
And Yes! the concept will accommodate any width firewall, as the mounts will
be a bolt on arrangement and these could vary in any length.
To my way of thinking this is only a logical extension of all the ideas put
forward so far and combined into the one unit.
George (down under)
Let me get this straight George. You are going to make a cast aluminum oil sump
with motor mounts built in? If so I think it is a pretty good idea but it might
be rather heavy. My guess is six pounds plus or minus one if you can hold
the wall thickness to .150 inches or about 4 mm. A tall order for a good foundry.
That is a 12 inch long sump box three inches deep. Not counting the actual
rubber bushing brackets bolted on I assume.
Paul Lamar
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