Check out the gas/glow thread here in the engineconversions.Theres to much to explain but after you read just the first few,maybe 6 pages youll get the idea.heres a pic of my 31cc ryobi i just did.Cut out center of flywheel,trued up in lathe,then screwed hub on.You can see the magnet in the flywheel hub.I also rounded the cylinder for a more airplane look.Total weight as in the pic with ign is 3-1/4 lbs.I would really suggest you go to the gas/glow thread to help with a decision.But it might be easier in your position right now just to get a ccw engine,what size are you looking for or what size and style of plane are you going to put it on?