Heavy Oil Engines for Aircraft: A Hot Plate Device Combined with Special Diffusers for Use with Low Compression Engines

IT is but recently that high‐speed light‐weight heavy‐oil engines have been fitted to aeroplanes, the most promising being the Junkers engine, employing their well‐known opposed piston principle in combination with two crankshafts geared together, and the Packard engine which is now in production in America and is standard sed in a Ford machine. The latter engine is air‐cooled, and both are high‐compression engines working on what is generally called the Diesel principle, though actually an English invention. While it is admitted that these engines are capable of improvement, and while it is hoped that they will soon reach a stage of perfection, it is claimed that a low‐compression engine will always be cheaper to buy and to maintain, smoother to run and lighter in weight than a high‐speed “Diesel.” The reason for this is principally the high pressures involved in the latter, owing to which, and on purely mechanical grounds, the “Diesel” engine will certainly not be more reliable or “simpler” than a petrol engine.