"Pumpless Pumping" or How to Raise Steam in a Stanley Without Elbow Grease.

The main fuel pressure bottles fitted to all Stanleys up to the introduction of the 740 contained a bit more than 0.8 gallons. Or, in terms of available heat, more than 100,000 Btu, if filled with either gasoline or kerosene. A 23 by 14 inch (20 hp.) boiler weighs 340 pounds and contains about 80 pounds of water at the normal water level. Taking the specific heat of the boiler to be 0.19 ( i. e. the same as steel), the total heat required to raise a full head of steam is about 58,000 Btu. Thus, if the pressure bottles are full, they contain more than enough fuel to raise steam.

The air tanks fitted to Stanleys from April 1919 have a capacity of about four gallons of air at 150 psi. If one assumes that 80 psi is sufficient fuel pressure for raising steam, the air tank has the capacity to feed all the fuel needed to fire up the car six times, assuming one starts with cold water! The portable air tanks sold by auto parts stores are even larger, so noncondensing Stanley owners can also use this trick.

The trick is to end your day of driving with very little air in the pressure bottles, thus they should be nearly full of fuel. On any convenient stetch of road where little steam is needed, like a down hill grade, allow the air in the main bottles to escape, or, in the case of a car fitted with an air tank, use it to raise the pressure of the pilot tank. (If the air tank pressure is lower than the fuel pressure, one can even feed some of the air back into the air tank!) Depending on the size of your fuel pump, the main fuel pressure should be back to normal in from one to two miles. It does not matter when this is done, or whether it done all at once or by several small steps during the day, so long as the pressure bottles are essentially full of fuel at the end of the day.

The next time you raise steam, use the air bottle whenever you wish to increase the fuel pressure. In the later condensing cars, simply open the "air bottle" and "main fuel bottle" valves under the sill of the front seat.

I have found from experience that I can raise steam every day for a week of touring without pumping a stroke, using the built-in air tank. As the boiler is usually still quite warm from the day before, not much air is needed. As an example, I just completed the five day tour near Quechee, Vermont (USA), firing up six times and still having 100 psi. in the tank when I got home. (Total mileage: 733)