Paul
I have a dream project of building a Howard DGA 15 in composites. The problem
is the engine. I do not want to use an old radial but two 13Bs driving a 99
inch prop at a max of 2800 rpm. I figure two 13Bs could deliver 400 to 500
hp, and look ok under a little longer cowling.

What do you think, doable?

Regards,
Norm Parmley

Dreams are only thoughts however, they alone keep us looking to the future.
Norm Parmley January 12, 2011

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SZP is the Howard DGA capital of the world and what you just
suggested would be considered blasphemy around here :)

That might work but the belt drive would have to be well
over 3:1 to drive a 99 inch prop. Now why don't you just scale it down.
Nobody will notice and there will no longer be a gymnasium inside :)

Use a 3 rotor and move the real firewall back a few inches.
The scale cowling will appear ok but there will be a tunnel
in the firewall to accommodate the 3 rotor aft end extra length.

Paul Lamar


I say extend the nose to allow the 4 rotors in line.  It might

look a bit like a Fairchild 24 with a Ranger (vs with the Warner)

but I don't think that's necessarily bad.

Also, I'd retain the steel tube fuse.  Easier/faster to build.

Go for composite wings and tail. Maybe the tail cone aft of the

cabin in composite too.


Matt-

I say... use 3 - RX8 P ports arranged so each is at it's correct location for a planetary reduction unit that doubles as the forward mount and each motors shaft attached to a planet (planets stationary of course) Then you could turn a 108 inch prop really slow.

Way back when I used to fantasize about building a Lionheart this way.  It's only time and money... neither of which I have.

Chris Cosman