Pusher fuel tank

[Kev]

I am interested in pusher glow planes. Would like to know about fuel tank placement. I do not want a pump and will be using a .46 size motor. If the tank is at the CG, how far can the motor be and still draw fuel? Would a bleeder tank at the motor work? If the tank is at the motor and nose weight is used to balance (with a full tank), will this effect flying as the fuel goes down. Thank you.

[CDNshy_guy]

the fuel tank needs to be level with the engine.
to high will give it to much gass and over heat it.
to low and you don't get enough gass.

[Dave Robelen]

Hi Kev,
First remember to face the tank forward and run the tubes back to the engine. As long as the tank is not really huge the CG shift with fuel burn should not be any great deal diffferent with the engine in the rear. With a forward mounted engine the model takes off nose heavy (relatively) and lands with the opposite condition. A pusher will start with the CG more aft as you note and get more nose heavy through the flight.
Running without a pump and a rear mounted engine has other effects that may be more of an issue. For example, when you lift the nose to climb, the engine will go rich and slow down when you are looking for peak power. Often the effect shows up in a landing flare as well where the engine tends to load up. A header tank would be a big help, quite possibly muffler pressure would be enough to keep the small tank full.
Regards, Dave Robelen