OCR Text |
Show Port Dual Exhaust Makes Wonderful I Increase in Motor Efficiency. The remarhahle efficiency of the high speed, long stroke Don motor is dependent upon a number of unique features, which have been incorporated incorpor-ated into its construction by its designer, de-signer, Mr. Etienne Planche, formerly former-ly of the Peugeot Co. of Paris. One of these features in particular, the , Dort dual exhaust, is responsible for a gain of nearly 12 per cent in horse power, as shown in a series of recent engineering tests. In making these tests the Dort dual exhaust pipe was removed and the ordinary single exhaust tube generally gen-erally found in motors of this class was substituted. The engine was then put through a series of brake horse power tests at various rates of i speed from six to forty-five miles an hour. Then the exhaust was removed remov-ed again and the Dort dual type, which is standard equipment on all Dort cars, put back on again. A similar sim-ilar series of tests was then made and plotted out on power curves, as the first tests were registered. It was expected ex-pected that the dual type of exhaust would show an increase in horse power pow-er and efficiency but that a gain of 12 per cent wcnld be registered was a surprise to all concerned. The above tests were made outside the Dort factory fac-tory by a firm of engine builders and the Dort Motor Car Co. was not notified noti-fied of them until they were completed. com-pleted. For the benefit of those motorists to whom the dual type of engine exhaust ex-haust is not familiar, the dual exhaust ex-haust may be simply described as two separate exhaust pipes cast in one piece. The object of this form of casting is to. allow the cylinders to exhaust alternately first Into one pine and then the other. This allows the exhaust gases of cylinder No. 1 to De carried away before cylinder No. 4. the third cylinder in the Dort firing order exhausts into its senarate section sec-tion and its gases have had ample opportunity to pass out. at even the highest motor speeds, before cylinder No. 2, the last cylinder in the firing order again exhausts into the same passage. This feature in the Dort motor costs about two and one-half times as much to cast, but bach pressure press-ure is entirely eliminated and the Dort people feel that the extra expense ex-pense is well warranted. |