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

 
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