Hi Guys, I have been following this thread for a while and want to commend all the great work. There was some consern voiced about the reliability of the glow plug and battery life. I have been experimenting with this method for about a year and have added a diode in series with the battery to limit the current to the plug. As previously stated, the plug does not need to glow white hot to maintain combustion. I use a bypass switch across the diode for starting. This has allowed me to use FAI fuel in all of my glo powered planes including my four strokers. As you all may already know FAI fuel has no nitro. The diode may work well also for this application. There is another device manufactured by Nelson that acts as a smart glo driver. It is a little expensice but works great. It cost around 60 bucks but limits the amount of power to the plug. I think it actually reads the resistance of the plug and applies current as needed extending the battery and plug life. $60 is a little expensive and I like the cheap diode better. [8D]