No problem with the true experimenter, but a couple of things to think about. I think one reason the Ace HDWR valve was used is that the lines in the Kitfox kit feeding the heater are half inch. I have spent hours looking for a heater valve in the online auto sources that are half inch. If someone ever finds one please post it to the forum. Be careful when assembling the parts. The typical Rotax install uses one inch ID (or mm equivalent) tubing to the radiator. If you are using VW, Corvair or Subaru, no problem. The factory supplies the "T"s that adapt the one inch to the half inch outlets to the heater. This might be the hardest item to find in the sizes you will need to adapt Rotax to automobile, or computer, for that matter. I doubt such an adapter exists. If you can make your own - no problem.