Spark plug cans for unshielded plugs
This is a rare find. The first Ercoupes had unshielded ignition systems, featuring very short spark plugs. These planes did not need the cutout in the top cowl, nor the spark plug fairings. To allow radio installations in such a plane a spark plug can was developed that would go over the unshielded plugs thus converting the unshielded system to a shielded one. It requieres the use of shielded magnetos, which was the case with the Bendix kind.
See how short the plug is! Champion is selling a similar short REM37Y shielded plug. This plug is marked Champion M41E.
The shorter plugs allowed NOT to butcher up the plane by cutting holes into the top cowling. Neat!
Some history here: ERCO engaged Morehouse to design the engine for their new plane, there being no suitable motor of 60 horsepower or more. At that time,Continental made a 40 horse only. Mr. Morehouse produced an inverted 4-cylender engine of suitable power, and the prototype Ercoupe cowl was designed for it. At that time, Continenal brought out the A-65. The price was less than what ERCO could produce the Morehouse engine for, so they certificated the 415 with the "flat four." The cowl line, with the better forward visibility, was kept. The flat plug was used at first. But with the popularization and affordability of radios, shielded ignitions systems became manditory. The cans served untilthe bumps were introduced. Then standard shielded ignition wires could be used.