I was not aware that they changed over to the more practical 12 volt systems on that engine.
Good thing to know!
You might look at a row of 12 volt computer cooling fans for cooling.
They draw less power than a bigger electric radiator fan. And some are high volume fans.
I've used the little squirrel and box fans for many of my projects.
Ex: I built a motorcycle helmet forced venting filtered cooling system by mounting a small 12 volt squirrel cage blower to the back of my Helmet and plumbing it to the front to blow onto my face. It was filtered because of my allergies were rampant and I loved riding, but hated the sneezing and watery eyes. The plumbing from the fan to the front of the helmet was flattened out pvc tubing I heated with a salamander heater and squashes against the helmet for a blending form fitting look.
It plugged into the bikes battery and the cord was bundled with the communication cables. It worked well and I still drag it out for high ragweed pollen count days. I was able to make it unobtrusive and naturally balanced.
Maybe a row of small 3" box fans can be fit in the intake and ducted onto the engine. By using multiple fans you can control the amount of air flow volume.
Just remember to factor your engine heat exits in the low pressure areas of the bodywork and you'll need less forced fans when moving.
Marketing the body work would be a nice way to recoup your development cost. Or at least to offset it. I'd be a customer! I could certainly see a market for that design for the home experimenter like myself. Although what I envision mine would need a longer bodywork than what you're building. I'm a frame/ engine builder guy and body work is not my strong point, but stretching it a little is not beyond my skill set. Your body might work just fine if I placed the engine between my knees like the Quasar. Which is a possibility, especially if I can get one of Fred Hayes Diesel KLR motors! His engine just begs to be used in an aerodynamic bike! So many possibilities!
(EDIT: I see Fred has developed and Competed in Craig's Ohio Challenge with a very slick Diesel Streamliner this Summer. Way to go! Fred!)
I do like the way Craig did his aerodynamics testing and refinements with floppy plastic sheeting. Quick clean and easy to fine tune. Not to mention very light weight. I had to grin when I heard he was using milk carton material for generation 2. I really hate working with itchy fiberglass and resin. All that sanding!!! Yuck!
But, being as Craig is an Industry Professional and Garage Mechanic like the rest of us I would expect nothing less than the most practical method for testing an idea.
Ya'll have a good day!
Gotta get out in the shop! Customers are waiting on their bikes!