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

Paul,
Thanks for your comments it all helps.
My local foundry chap has done aluminium wheels and the rims are pretty
thin - he says it worked real well - time will tell !!
I have a suspicion that the current plate design leaks because of flexing
under load.
I figure if I make the whole lot one piece with stiffening ribs it should
eliminate this problem (if indeed it is a problem).
 I can live with a little extra weigh for ease, simplicity and piece of
mind.
Anyhow it will be a trial - nothing ventured nothing gained.

4mm on the oil pan you say, I was hoping for 3mm with some ribs - we will
see what the foundry can offer.
How much does the current 1/2" plate weigh.
BTW what is the side dimensions of the modified sloped pan to allow for
under pan radiator fitting.

George (down under)

As I recall Tracy's adaptor plate weighs eight pounds. So you have that weight
come hell or high water. The idea with the motor mounts on the plate
only adds two pounds to the weight of the plate. One can figure things 
out for one self as aluminum weighs .1 pound per cubic inch.

For example; Lets say we had a 1/2 thick plate between pan and engine.
Length would be about 18 inches and width about 13 inches not counting
motor mount ears. If we had to buy a such a plate it would need to be
about 17 by 18 to allow for cutting the ears.

Cut volume would then be 13 x 18 x 1/2 or 117 cubic inches.
Weight, not counting motor mounting ears and holes in the plate,
would be about 11.7 pounds. One can reduce this weight by either cutting 
large holes in the plate or putting it in a mill and pocketing
out most of the material. That is a very time consuming and costly 
procedure. All and all a very inefficient way of making motor mount
brackets.

Paul Lamar
 
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