The Nitro RC Fuel System

The Radio Controlled Nitro Car Fuel System Did you know what all RC Nitro Cars have fuel injectors? Well sort of, basically the exhaust pipe has a fuel tube going back into the fuel tank, this keep the tank pressurized and keep the fuel flowing. In the image on the left you can see this tube loop between the air filter and the fuel tank.

There are two option when it comes to tuning your nitro RC fuel tank:

1. The size of the fuel tank

A bigger fuel tank will give you longer runs, but the car will start with more weight which is only a consideration during races. It's not always the best idea to run your car for too long, radio controlled cars tend to over heat, with proper engine tuning is possible to counter this but it's still not good to push them for too long.

2. The inner diameter of your fuel tube
A larger inner diameter will allow more fuel to flow, but seeing as your controlling the fuel flow from the carberator it doesn't really make too much of a difference. I would only consider replacing the standard tubes if I was having problems. Wide diameter tubes sometime come loose during the race and can let air into the system. If the tube is too thin it will restrict the flow of fuel.

When in doubt use the manufacturer recommended diameter and fuel tank size.

Troubleshooting Tips

Your fuel system needs to be air tight, if any air is getting into the system it will make your engine run lean, which is very bad. This means that not enough fuel is getting to the engine, which in turn means that there isn't enough lubrication in the engine. The result is the engine starts to over heat. As it overheats your engine will start to lean out further.

At the end the engine will just stall, either to the fuel evaporating before getting to the combustion chamber, or glow plug failure. This can seriously shorten the life of your engine. I find that nine times out of ten, when I've tried all the basic checks and the RC car still won't start due to an air leak in the fuel system.

Often it's not a serious problem, and you can easily test the system by blowing though it, the same applies to then you have a leak in your engine, open the throttle and blow on the fuel tube. you can then use water to find where the leak is, just watch for the bubbles.