O,K,  BTW my intake does have alt air that could be hot air from the cool tube.  RE boring the housing for direct injection is a good option I think.  Were would you put the injectors?  Jerry

Jerry, Two different options on injecting into the housing. 1, inject into the negitive pressure area within about 1-2 past the intake port. (Everett tried this one) 2, inject high pressure near the lead spark plug. Cars/boats have used a annular injector that injects around the plug with aspecial adapter. This solution is complex however as you need a high-pressure pump, to overcome the compression pressures. BTW Mistral is doing this for their "heavy fuel" engine. They are making a spark ignited diesel or Jet-A version.
Bill Jepson