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 lubrica tion of it.
In all high speed engines of the mobile type, ex cept those built for airplanes, light and medium body mineral oils give the best service. In airplane en gines castor oil is employed, and though it is a vege table 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 heav ier the lubricating oil should be, and the other way about.
Nearly every maker specifies the kind of lubricat ing 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 lubri cate, 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 Wash burn Refining Co., 11 Broadway, New York, and either company will tell you the best and most eco nomical oil to use.
How Water Economy Is 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.
Where water is used inside of the cylinder to pre vent preignition or to keep down the temperature, the water must be free from lime, for this will do a lot of damage. To prevent it use either rain water or rig up an apparatus for distilling it.' In stationary engines, where water is circulated around the exhaust, the heat will cause the solid matter in it to be deposited, and the water spaces will finally choke up. When this happens the exhaust valve may burn out and a new one will have to be put in. This not only costs money, but you will have to shut down your shop while it is being done.
To prevent this untoward occurrence, make a solu tion of 1 part of muriatic acid and 19 parts of soft water. Now draw off the water from the cylinder cooling spaces every fortnight and fill them with the acid solution. Let the solution stay in over-night, but not longer, or it will act on the iron. The acid solution will soften and break up the lime, and you must then wash it out with clean water.
Where stationary and portable engines are run in winter and there is the slightest danger of freez ing, let the water out of the jacketed cylinders and from the tank, or hopper, where these are used, every night.
In a motor car or other mobile gasoline engine the water must be strained before it is put into the radiator whenever you fill it. Drain off the old water once a month and fill it with clean water. Every three months wash out the water spaces and radiator with a hose and finally clean out the water jackets with a hose every year.
For mobile engines where the temperature does not drop to more than 10 degrees below 0 Fahren heit in winter use an solution in the radiator, made of 25 per cent of wood alcohol, 15 per cent of glycerine and 60 per cent of water.
To Secure Ignition Economy.—Electric Ignition,. —To secure economy at the ignition end of an en gine you must see (1) that the battery does not run down or get weak; (2) that the magneto gives a spark at least inch long, (3) that the spark con tacts or the points of the spark plugs are clean and where the latter are used, that the spark points are separated the proper distance,' and (4) that the timer is in adjustment.