| November/December 1972


'Loyal'--second design. Courtesy of Arthur P. Stone, Highland Drive, Box 246, Elfers, Florida 33531.

Box 246, Elfers, Florida 33531.

I have always been interested in unusual types of engines and when a boy in Brighton, England 68 years ago, I saw a very brief description of an engine made in France called the 'Loyal'. No details were given other than a diagram of the cylinder showing the valves and hot tube ignition and the statement that it illustrated the theory of stratification of the gases.--(This will be understood from the 'sequence of operations').

Very few of these engines must have been built because I have never seen any reference to them in any book devoted to the subject of 2 cycle engines since.

To anyone familiar with 2 cycle engines, it would seem dubious whether this engine would actually work, however I designed one as simply as possible and it works perfectly, has good power, idles nicely, and of course needs no gas/oil mixture. My friend, Mr. Crafts of Akron, Ohio has built two different size engines from my drawings and has demonstrated them at various shows.

I hope that you will find the following description of my engine of interest. This little engine is a two cycle, but unlike all other types, employs no preliminary compression of the charge, all operations being performed within the cylinder--consequently no crankcase is necessary. Intake and exhaust valves are fitted, both automatic (spring controlled), no cams or gears. No mixing of oil and gas.

This is a slow speed engine, 500-1200 rpm. but on account of the long stroke gives very good power, (a 1?' bore engine drives my 9' lathe). The principle upon which my engine is based, I believe, originated in France about 1900 or perhaps a little earlier, and was never widely known.