Hi pete,
I have spent lots of time working on these 31's. I have auto-cad drawings of the backplate and reed valve mounting. I make the reed valve mounting plate out of 6061 aluminum. I mount the reed valve mounting plate to a really seroius 1/4" thick 'bow tie" shaped mount. I'm using a 3 7/8" X 2 3/8" bolt hole mount with 8/32 SHCS. I then use 4 1/2" Square 2" long standoffs. I had to make some fixtures to machine the reed valve plate. as you can tell the reed valve has a small preload on it so it closes air tight.
I currently have 2 flyable 31's. Both where tested on the Big Bingo. Sadly the Big Bingo bit the dust last wednesday. It got tangeled up in the saftey fence doing some touch and goes. I got 11 fifteen minute flights out of it. I ran both of my 31's in it and both of them never missed a beat. I'm currently building another low wing test bed.
Send me a real E-mail address if your intrested in pushing these motors to the MAX. I have a small machine shop with unlimited resourcees. I have lots of pictures if intrested. Not trying to sell anything. I'm retired and love working on these motors.
Larry
[email protected]