In the early 70s, Lou Ross designed and developed a couple of large multi-cylinder engines for military applications as target drone power plants. Finished in 1972, this is a 7.0 cubic inch opposed four cylinder, two-cycle designed to burn methanol on glow ignition. The glow ignition eliminates the need for points, coils, and heavy batteries allowing the drone to carry more fuel for long distance flight. His 3.5 cubic inch two-cylinder drone engine is most desirable for smaller target drones and high speeds. He cast the crankcase integral with the cylinders in these engines, which is typical of his much smaller model airplane engines. His line of model airplane engines is highly collectible today; however, only a few examples of these large drone engines were produced.