Perry Mick wrote:

Here is the latest drawing of my new engine mount for the LEZ, and the
new rad that doubles the volume. This new volume is in the ballpark of
what is in the stock 2nd gen car rad. Shown are the inlet ducting to the
rad, without the side walls.

Perry

Here are my suggestions.
We came up with an easier way of doing that MM after that rectangular beam scheme
was originally proposed on here. Namely take the lower MM tubes loads down to the
landing gear bolts. Do away with the two vertical rectangular beams. Much lighter
simpler and much less welding. Here is one 3D of the new design and a picture of the cut
away hell hole. Make a couple of 4130 cups that go under the nuts on these landing
gear bolts. Strongest place in the whole airplane. Makes it easier to service stuff in the
hell hole too. The P51 type side beams give clearance for a muffler.

Yes, I know about that, but don't really want to cut into the fuselage
structure just yet. I would rather just bolt something on.

Are you still using
the stock exhaust manifold?

Yes.

If you decide to go with a muffler in the future
the P51 type side beams will help. Jerry Hey can sell you a cross beam that
goes between the gear box plate and the back of the engine that you can cut down
to your needs. Or you can have one bent up locally. I can send a drawing of that.

I've already made the beam and front mount and a new oil pan. Another
view attached with those parts turned on.

If you double the thickness of the rad that will restrict the air flow more
and your NACA duct will work worse than it is now. The ducted fan
did a good job of sucking air into the NACA duct and through the rad.
Without the ducted fan it will not be easy to get the air to flow through
that double thickness rad. The counter cross flow rad design is very good
however.

Paul Lamar

I already lowered the inlet lip on the naca over an inch, probably about
a year ago, so that it is a little bit of a scoop. Noticed absolutely no
difference in cooling with the ducted fan, but it might help with this
rad. I definitely need to increase rad capacity now, and this is about
the only way to do it.

Perry

That just shows to go you how bad it is :) The high velocity air you are looking 
for is nowhere near the opening. An inch is probably inadequate for the boundary 
layer air bleed on a P51 ram air scoop that is that far back on the fuselage. 
My guess is the boundary layer is several inches thick all the way back there.
But why guess?

I know you still have my water manometer so put a velocity rake back by the NACA
scoop consisting of an  array of pito tubes spaced an inch apart and report back :)

Here is a picture of a velocity rake I built for testing Tracy's airplane.
I wanted to make sure I was reading the real dynamic pressure.

Paul Lamar
 
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