CARBONIC GAS ENGINE
The six-cylinder carbonic gas engine described herewith is the product of Mr. Henry Rompel, Kansas City, Missouri.
This is perhaps one of the most interesting of its kind to have been developed during 1916, and its appearance in the model aëroplane field adds weight to the claim that mechanical engines will soon replace the rubber strand as motive power for model aëroplanes.
Mr. Rompel’s engine is of rotary, carbonic gas type, having six cylinders, a bore of ⁵⁄₈″ and a stroke of ³⁄₄″.
The intake is derived through a rotary valve which also acts as a crank shaft bearing, thereby saving weight.
The exhaust is accomplished by mechanically operated valves situated in the heads of the cylinders being opened by the aid of rocker arms and push rods, which gain their timing from a cam placed on the crankshaft.
To save weight in construction the crankshaft, connecting rods, pistons and cylinders were made of telescopic tubing with a side wall of one thirty-second of an inch or less in thickness.
The engine has a swing of 5¹⁄₂″ over all, weighs a little less than 8 ounces complete, and is operated on 1,500 pounds pressure (carbonic gas) and at a speed of 3,500 to 3,700 r.p.m. will develop about 1 horse power. While spinning a 17″ propeller with a pitch of 20 inches it will deliver a thrust of 21 ounces, and has a duration of 40 seconds. Two hundred and fifty-six pieces were embodied in its construction.