COMPRESSION OF ENGINE

Manawatu Times, Volume LIV, Issue 6863, 19 March 1929, Page 10

COMPRESSION OF ENGINE

Point for Car Owners Frequently it happens that the owner of a car which has given him good service decides to change it for another of the same make, but with a new type of body or some alteration that has cc-me along in the meantime, and who afterwards complains that the engine of the new car is not nearly so smoothand sweet running as was that of the old one. At first sight it may appear that the difference is either imaginary or is due to tightness of tho bearings and pistons, or incorrect earburation — things that will naturally wear off with running in and adjustment. But beyond these possibilities there is another more important one. Every year after its first appearance as a- new model every' ear goes through forms of evolution aud improvement. It often grows either larger or heavier. Sooner or later arises the need to put up the power of the engine, and eventually the compresison is raised. As it goes up so does the tendency of the engine to thump at slow speeds also increase. It is not uncommon for makers to Taise the compression of an engine. But this higher compression is often the cause of the roughness of which the owner complains. There is no remedy for it, but much can be done to make the car more pleasant by beiDg careful over the selection of fuel. It is worth while to experiment with different brands of petrol until one has been found that really suits the engine. A good spirit with a small percentage of benzole “or alcohol added, is usually very satisfactory.