Tuesday Torque: Buckeye Oil Engine

Good One, Merle. Many Thanks!  The Buckeye Model L was a two-stroke “hot-cup” semi-diesel, most accurately called a medium compression oil engine. It had a medium pressure fuel injection system that sprayed fuel into a precombustion chamber. The base of that chamber (called the “Ignition bowl”) was heated by a kerosene torch for starting, and because it wasn’t cooled via the water jacket, it heated to a dull red under power and that was enough to sustain combustion after the engine ran a while. With a low compression ratio (by diesel standards) of about 11:1, the fuel needed to be vaporized by heat before it would ignite from heat of compression. The engine had no valves. It breathed through ports and inhaled via the crankcase, where the movement of the piston in a special chamber at the bottom of the cylinder pushed air into the combustion chamber.

Under a maximum 125 hp load, this engine would use six to seven gallons per hour. As a display engine under no load, its operated at half speed, 100 rpm, and is really barely running and uses very little fuel. Compared to modern diesels, oil engines are VERY inefficient. Compared to diesels of the '20s and '30s, they are at least 30-40 percent less efficient. Oil engines had three redeeming characteristics over diesels back in the early days (back into the 1890s):1- They were considerably less expensive than a diesel, 2- They were "omnivorous," and able to operate on a wide variety of fuel oil grades, from what was basically crude oil with the big chunks taken out, to the lightest oils similar to what we now call "diesel fuel." 3- they were portable. Despite being omnivorous, oil engines were subject to having trouble with poor fuel quality. The heavier, less refined oils tend to leave lots of deposits in the vaporizing chamber, on the rings, piston crown and in the fuel injector. This engine came from the beginning of the era when fuel oil began to be of consistent quality. Though this engine runs on modern #2 diesel fuel, it would be happier with something a little heavier like bunker oil, which is about 20 percent heavier than diesel. Up to about 1920-25, diesels had to be very large and complex, most using air injection (fuel injected by high pressure compressed air). Once solid injection (mechanically injected high pressure liquid) was perfected, and demonstrated by the Germans who used solid injection diesels in their successful World War I submarines, it made diesels more practical and portable. Once solid injection was applied to diesels, costs, complexity and size came down and the efficiency of a diesel then started to make diesel cost effective versus oil engines. Oil engines were produced into the late '30s in the first world (later in other parts) and used into the '50s. This engine was built by the Buckeye Machine Company, which started business in 1909 in Lima, Ohio. The Model L, originally called the Buckeye-Barrett oil engine, went into production in 1917 and was manufactured through 1929, with leftover stock sold for many years later. Buckeye would become famous for building a variety of large industrial and marine diesel engines but ceased manufacturing in 1948. Maumee Valley Antique Steam and Gas Association