ORIGINAL: Geistware
I held a fellow flyer a week or so back and his OS40 could not get hot enough to burn my hand if I held it. The engine kept dying. My gas engine would be cool enough to touch after I landed, but ran great. We kept his glow driver connected (wire with alkaline battery) and it flew great. I am don't know enough to analyse why it worked, it just did!
Its easy to explain.. the coold air and high velocity airflow cooled the glow engine so fast... it killed the glow. The gasoline engine had a spark ignition system and didn't depend on heat retention from one combstion cycle to fire off the next. Putting on the glow power and leaving it equalized the situation... you provided the heat for ignition despite the airflow cooling the engine.
Try copper-wire strapping some soda can aluminum onto the engine to prevent air from hitting the cooling fins... the engine will run without the glow driver. (careful... you can excessively prevent airflow and overheat the engine. and its possible to create RF interference....)