How Does It Work?

How Does It Work?

This is a question that comes up rather frequently so I thought it deserved a proper explanation. The simplest and shortest answer in regards to the Stanley’s operation is to say that it uses gasoline to boil water which creates steam. The steam is then injected into the engine that in turn uses its expansion to create mechanical motion. If that doesn’t completely satisfy your thirst for knowledge, the easiest way for me to expand upon that is to divide it into three separate systems: The pilot, main burner and steam. These three systems work together to power the vehicle.

The Pilot

The pilot is a constantly burning flame that is used to ignite the main burner. The pilot fuel is stored in a separate tank from the main fuel. It can be Hexane, Naptha, or Coleman Camp Fuel. The pilot fuel  tank is pressurized to 25-30PSI. The fuel passes from the tank through a series of valves to the pilot burner assembly located in the main burner pan just below the boiler. The pilot burner assembly consists of a vaporizer and burner. The vaporizer heats the pilot fuel to a vapor then it is sprayed in the pilot burner where it is ignited. The pilot serves two very important purposes. One, to ignite the main burner when it is cycled on and two, to vaporize the pilot fuel so it will keep burning.


The Main Burner

The main burner heats the boiler to produce steam. The main burners’ fuel is stored in a 16 gallon tank at the back of the vehicle. It is pumped from main tank into a smaller vessel that holds about a quart, where it is pressurized to 120PSI. The pressurized fuel passes through a series of valves before going into the main fuel vaporizer where it is heated to a vapor. It then leaves the vaporizer through the branch forks where it is sprayed into the mixing tubes of the main burner. From the mixing tubes it travels through the burner grate where it is ignited by the pilot light. The flame applies heat to the bottom tube sheet of the boiler to create steam.


The Steam

To create steam we need water so that’s where we’ll start.  The water is stored in a 28 gallon copper tank under the seat. It is pumped from the tank through numerous valves into the feed water heater located in the exhaust flue of the vehicle where the water is preheated. After leaving the feed water heater the water is pumped into the boiler. The boiler is of the fire tube variety in which hot gases from the fire below pass through a series of copper tubes and exits out the top. As the copper absorbs the heat from the hot gases it gets transferred to the water contained in the boiler. The water in the boiler is then heated into steam. The steam exits the boiler through the throttle valve and passes through the super heater which is located between the main burner and the boiler. In the super heater the steam is brought up to a temperature of 600 degrees. Upon leaving the super heater it will go to the engine which is mounted beneath the back of the vehicle. The engine will then translate the steam expansion into propulsion of the rear wheels.