CHAPTER VIII

HOW TO PRACTICE ENGINE ECONOMY

If the hoary and bewhiskered adage which tells us that an "ounce of prevention is worth a pound of cure" was stenciled on the side of every internal combustion engine sold and those who buy them would heed the world old saying, there would be at least 50 per cent less of them go to the scrap heap every year.

A man who has had little or no experience with machines in general and engines in particular is apt to think because a power unit of this kind is made of iron and steel all he needs to do is to feed it with fuel, lubricate it with oil and give it water once in a while and that in turn it will deliver power without further attention.

And so an engine will run for a while, sometimes a long while, under these conditions, but to get it to develop its full rated power and, what is of even more importance, keep it in service for the longest time, there are some other things that must be looked after and diligently, too, for using the right kind of fuels and lubricating oils and keeping an

ever-watchful eye on the engine are the big factors that count for economy.

About Fuel Economy.-Gas Fuels.-The difference in the prices of natural, producer and city gas is not of such great importance when you are running a small engine. Of course, if you are living in a region where there is natural gas, by all means use it, but if not, use city gas, unless you are running an engine of 40 horsepower or over, and then it will pay you to install a suction gas producer.1

Gasoline, Fuel Valves and Carburetors.-In mobile engines such as those used for running motorcycles, motor boats, motor cars and airplanes, it spells economy to use a good uniform grade of gasoline, and the only way to get it is to buy it of the Gulf, Texas, Standard Oil or other good company.

In stationary engines, especially those of large size, the quality of the gasoline can be of a lower grade than that used in mobile engines. Before using gasoline it is a good scheme to filter it through a piece of chamois skin or, where it is used in large quantities, strain it through a piece of wire gauze having a fine mesh. Foreign particles of matter that get in the gasoline will clog up the fuel valve or carburetor, and this will cost you both time and money.

Where a fuel valve is used on a gasoline engine it is adjusted to a nicety before the engine leaves the 'For data concerning gas producers write to the Otto Gas Engine Works, Philadelphia, Pa.

factory, and it will not need readjusting unless something gets in the gasoline and chokes up the needle. But with a carburetor it is different, and it is up to you usually to see that it is properly adjusted to mix the gasoline and air in the right proportions.

If the fuel valve or carburetor gets out of adjustment your engine will lose power and it then becomes very wasteful of fuel. To get either of these devices adjusted exactly right, it takes a man who thoroughly understands the particular make your engine is fitted with. You can learn to make these adjustments yourself if you have the time and the patience of Job, but don't let any alleged engine mechanic fool with it unless you know that he knows just what he is about.

Kerosene and Crude Oils.-In oil engines having electric ignition kerosene gives better results than crude oils, because the cylinder is not kept hot enough to vaporize lower grade oils without leaving a lot of carbon behind.

In buying kerosene for your engine don't get the highly refined illuminating oil that has a fire test of 140 to 150 degrees Fahrenheit, but take the lower grade kerosene, whose fire test is 100 to 110 degrees Fahrenheit. There are several reasons why the latter is better than the former, and among these are because (1) it ignites at a lower temperature, (2) it evaporates easier, and (3) it is very much cheaper. Heavier fuel oils such as solar, gas and even crude oils can be used successfully in engines which are

fitted with hot ball or bonnet igniters and hence these engines are very economical to run. The very

cheapest crude oils as they come from the wells can be used in Diesel engines because the temperature of the cylinder is even higher, hence this type of engine is still more economical to operate.

Always filter the fuel oil you are using to get all of the grit out of it, for solid matter, however finely divided, in either a gas or a liquid fuel, is very apt to interfere with the lubrication of the cylinder. Finally, buy the fuel oil from a refinery which has distilled the gasoline out of it and by so doing you can run your engine for the least amount of money possible.

To Lubricate Economically.-Far more impor tant from the standpoint of economy than the use of the right kind of fuel in an engine is the lubrication of it.

In all high speed engines of the mobile type, except those built for airplanes, light and medium body mineral oils give the best service. In airplane engines castor oil is employed, and though it is a vegetable oil it is the heaviest oil known. Other than castor oil no vegetable oils or animal oils can be used for lubricating engines.

Heavy duty engines require an oil with a heavier body than those built for lighter loads. The chief difficulty with heavy oils is that they offer a higher resistance to the moving parts, and that they are very apt to leave a deposit of carbon; on the other hand,

an oil with too light a body is liable to burn up, and when this happens carbon is also left behind. If you can get an oil of just the right body for your engine you are practicing engine economy that is truly worth while.

In buying lubricating oil just bear in mind that the higher the temperature of the cylinder walls and the heavier the load the engine has to carry the heavier the lubricating oil should be, and the other way about.

Nearly every maker specifies the kind of lubricating oil that gives the best results with his particular engine, and if possible get the kind he names and stick to it. Never buy an oil because it is cheap, for cheap oil is poor oil, and poor oil does not lubricate, but it burns and forms carbon, makes the valves and the piston rings stick and causes the open end of the cylinder and the exhaust pot, or muffler, to smoke. In fact, a fellow's got to have more money than sense in order to be able to afford to use poor

oil.

If you are in doubt as to the kind of lubricating oil your engine needs, write to the Vacuum Oil Co., 100 Broadway, New York, or to the Platt and Washburn Refining Co., 11 Broadway, New York, and either company will tell you the best and most economical oil to use.

How Water Economy Is Had.-Next to air, water is the cheapest thing an engine uses, but don't let yourself believe that all water is alike, or that any kind will do.