However.
The first major setback has occurred. My AWD transfer case interferes with the K11 motor. So much for the simple coupler and adapter plate. The green circle is approximately 11" diameter - same as the K11. The red line shows where the interference occurs. The transfer case is only about 6" thick. But, I cannot extend my coupler and adapter plate becasue there is not enough room between the frame rails!
My only option is to offset the motor from the input shaft. I've been thinking about a small gear set (which then leads to rotation direction problems). Or reversing the motor and using another drive shaft to couple the transmission.
Then I remembered replacing a bearing on the NP242 transfer case of my old Jeep. Inside, they use a "Silent Chain" to connect the main drive shaft and the front drive shaft. There is, of course, a differential that I don't need. But the 2 main sprockets and drive chain should work well. This particular model is rated at over 1400 ft-lb torque! So I can either source these parts and modify them - or go direct to Ramsey or Morse and find the exact sprocket size/chain length to work for this.
CHAIN DRIVE DESIGN
Update 23 Mar 2013:
I've tried designing a purpose-build chain drive using industrial HY-VO chain sizes. The problem was the extremely high cost of the components. Apparently "off-the-shelf" industrial parts are not actually off the shelves - they are custom made on demand (but use "common" designs).
So the next step was to scour the web and parts manuals for transfer case parts that I could either use directly, or modify to fit. I took this opportunity to tweak my final output ratio (since the Talon gears were so close together). I was able to find some parts that would work and was ready to start pricing out the aluminum case and components.
THICK ADAPTER PLATE and MOTOR MOD
But some experienced guys over at diyelectriccar forum convinced me to investigate this further. I might be able to build a thicker-than-normal adapter plate and slightly modify the motor. Overall clearance needs to be 6" to clear the transfer case. And the width cannot be more than about 19.75" to maintain clearance to the front frame rail.
Upon further measurement and inspection, I found I could gain at least 2.5" by removing the cooling fan and modifying the aluminum end cap of the K11-250. And an the extra 1/2" could come out of the housing. This means I could utilize 3" aluminum for an adapter plate. I will install some sort of auxiliary cooling for the motor afterward.
