Make sure the engine you desire to convert is a ringed engine. (ABC engines don't convert well) Unless you change the bushing on the lower end of the rod to a needle bearing you will need to use at least a 16:1 oil ratio. If you convert to needle bearings you can raise the oil ratio up to around 50:1 without problems. CH as mentioned above is an excellent choice for ignition parts including the little 1/4X32 spark plugs. Good Luck, it's a very good project.