| August/September 2000

Otto Langen Atmospheric Engine


3 Edna Terrace New Hartford, NY 13413,

I went to visit my friend Wayne Grenning at his Lockport, New York, home early in February to see his latest project. Wayne builds fine scale production models of such engines as the Otto-Langen atmospheric engine, Sombart flame ignition engine, and the Springfield type 'A' engine.

Picture 1 shows his latest effort. It is a ? scale of a ? HP Otto Langen atmospheric engine. It stands about 6 feet from the floor to the top of the flywheel, with the guide rods extending much further. It weighs an estimated 700 pounds. This is a very close reproduction of the original Otto-Langen engines, with elements taken from the original patent drawings, and the living example of the full-size Otto-Langen at Kinzer, Pennsylvania. Features such as genuine flame ignition and slide valve were painstakingly incorporated into this engine. The cylinder column was machined from a solid billet of cast iron! This is a truly astounding piece of workmanship, which no other model manufacturer can even hope to approach. The fact that this engine will actually be produced in very limited numbers is even more amazing.

Photo 2 shows a general view of Wayne's shop. To the left is the ? scale Otto-Langen. Behind that is the hydrogen used to run the engine. Next is a 1/6 scale Otto-Langen. Behind that is an original, running Crown Gas Pump (more on that later). Next is a Lake-breeze hot air fan, also running (look Ma, no wires!). Next to that, on the wooden crate, is a 1/14 scale Otto-Langen, and off to the right is Wayne's 5 HP Otto engine with electric lighting flywheels. This is partially disassembled so 1/3 scale drawings can be made. We spent an enjoyable evening running the Otto-Langen, Crown, and Lakebreeze in an exhibit that would pale most engine shows!

Picture 3 shows the top mechanism of the engine. The toothed rack in the top center of the picture is attached to the piston, which is in the column. The only connection to the rest of the engine is through the clutch behind the rack, which engages when the piston falls quickly. As the piston falls, a catch on the rack causes a pawl to engage a ratcheted gear, which engages two cams to the counter shaft that can be seen in the picture. This does several things: it causes one of the cams to lift the piston up, which draws in a charge of gas and air. The other cam then moves a slide valve at the bottom of the cylinder, which admits the gas and air charge. The slide then moves to close the gas and air ports. Within the slide valve is a chamber where a flame is maintained. As the piston reaches the top of its travel, this chamber moves over a port in the cylinder, which causes the charge in the cylinder to ignite. This drives the piston up farther. The combustion gasses quickly cool, and the piston is forced down due to atmospheric pressure. The clutch gear engages the main shaft, which constitutes the power stroke. The piston then settles down, pushing the products of combustion out a port in the slide valve, as the main shaft coasts. The piston then releases the pawl, which at this point has disengaged the cams on the counter shaft, and the process repeats. A petcock on the exhaust outlet controls the speed of the engine. If the exhaust gasses are restricted, the piston settles down slower, and the firing process doesn't repeat as often.

Photo 4 shows the bottom of the cylinder. The two pipes at the right supply the ignition flame in the slide valve and its pilot light with gas. The main slide valve is in the left-center of the picture. In front of that is another slide valve, which serves as a safety valve. It controls the gas into the engine, as well as the exhaust. Basically, if the engine is turned backwards, the clutch engages the rack, and the piston draws a full cylinder of air-gas mix. If this is ignited, the engine can blow its top off. This valve shuts off the gas as the piston passes a certain point, and doesn't allow the piston to fall until the excess charge is released.