VINTAGE SMOKE
1929 OTTO KV 50 YOU OTTO KNOW
DIESEL WORLD MAGAZINE
SPECIAL THANKS TO ROGER KRIEBEL, MIKE MURPHY AND THE GANG AT SMOKSTAK
BY JIM ALLEN
The mighty Otto KV-50! With a 14 inch bore and a 22 inch stroke, it displaces 3,387 cubic inches. Rated power was 50 horsepower at 230 rpm and at that speed, it was cranking out a calculated 1142 lbs-ft. of torque. The listed fuel consumption at full load was around 3.5 gallons per hour... very economical. The engine had a shipping weight of 19,000 pounds. This particular engine was installed into a Lewisburg, Pennsylvania, ice plant in 1929 and ran an ammonia compressor as well as an AC generator. It was in full operation until the late 1950s, then on standby service for another decade. It was donated to Coolspring in running condition by the owner, Fred Coburn, in 1994. It was set up in the Earle T. Harvey building at Coolspring and the display was built to look like the area in which it was originally installed. The original compressor and AC generator is also mounted nearby and occasionally operated.
The engine in this story is one of the last built in the United States with a direct connection to the beginnings of internal combustion. If the name “Otto” tickles your memory a little, it’s because of Nicolaus Otto, for whom the four-stroke Otto cycle is named. The four-stroke Otto cycle is well known as a spark ignition cycle. Lesser known is that the Otto cycle is also seen on just about everything else, including compressionignition engines. The four-stroke, constant pressure cycle credited to, patented by and named after, Dr. Rudolph Diesel is completely different and the engines that run, or in the past ran, on this cycle are actually few and far between. You could actually say “your diesel... isn’t” but that’s for another story.
THE FIRST FOUR STROKES
wwwHistory has recorded Nicolaus A. Otto (1932-1891) was the first to develop a compressed charge, four-stroke engine in 1876. A good deal of internal combustion history had passed before that point, some involving Otto and some involving others, but all contributed to make the overall learning curve more shallow for the next guy. The road to success for Otto was paved when he teamed up with Eugen Langen (1833-1895) and formed N.A. Otto & Company in 1864. They built a successful atmospheric engine that started attracting investors. With investors came money for more development, fresh engineering blood and a successful product. By 1872, N.A. Otto & Company had evolved into Gasmotoren-Fabrik Deutz AG (GFD)... the cornerstone of what is now Deutz AG.