One other thought here. You will need to use a ringed nitro engine. Many "nitro", or glow engines these days are either "ABC" or some variation thereof. These engines have no piston rings, and the proper fit of the piston in the cylinder for both sealing and durability is highly dependant on engine operating temperature. If the temperature is off, (or even the fuel mixture), the piston will either not seal well, or can stick in the bore, ripping the con rod apart. Since you have no idea what your temperatures might run, AND your lubrication might be questionable, you will need to use a more conventional ringed engine for your experiments.

AV8TOR