Just a thought that occured to a few fellow flyers over the weekend , wouldnt it be smart to make a larger glow plug for larger engines? The discussion took place while running a ST 2300 inverted on a new plane. After 5 tanks and 2 plugs later we came to the conclusion if they made larger glow plugs to be able to handle the larger volume of oil and gas the larger engines consume the glow plug would last longer , burn better and make the engine run better. Why is it a glow plug is designed to fit a 40 size engine all teh way to a 120 size engine? It's the same size and the same fillement but it has to handle up to three times more fuel and expect to be able to keep lit. I am aware you can by a hotter plug but its still the same size just different thickness and composition of the fillement inside. What if a engine manufacturer made the engines with larger holes and larger glow plugs so we could run them inverted and not have to worry about a flame out or burned plug? You dont use the same size spark plug in your weedwacker as you do in your car so what is the theory behind the same size glow plug for most glow engines? We could cut down on glow plug failure ,reduce engine tuneing problems and maybe even burn the fuel more efficiently with a larger plug. Any theorys as to why a engine has not been made this way yet?