I'm primarily trying to reduce weight at this point. Not having an ignition system wouldn't hurt that goal. It would reduce complexity substantially as well, and eliminate a significant amount of radio interferance. If it burns twice as much fuel it isn't going to be a very good solution for economy, which is my ultimate goal. As light as possible, and for as long as possible. Making the manifold wouldn't be a problem, but how do you mount a glow plug?