Cox Tem-Trol

Temperature control was not maintained in any of the machining processes at Cox that were 1st, and 2nd operations on the screw machines and the Cox-O-Matic.

Temperature control was strictly maintained in the hone room where the cylinders were honed to final size and checked on an air spindle. The pistons were also centerless ground to size with a taper at the top in the hone room prior to the con rod being pressed in. Pistons had one, or two tapers depending on the model and when they were produced.  All dimensional tolerances where checked in the hone room  so everything was at the same temperature and that way  the piston to cylinder clearance could be properly determined maintained.

There was a double room where you put on your clean suit before entering the hone room, and only two people at a time were allowed to leave or enter so the heat mass of the human bodies would remain the same and not upset the temperature. We were only allowed into the hone room when the girls took a break, and there was 4 hone stations so two at a time would alternate breaks.  

Later, on the assembly line, the girls fitted the pistons to cylinders by hand and tried to get them to stop about 1/16" of an inch before the top of the bore for a good tight fit. The next step was to put the piston/cylinder assembly on a leak down carousel and pressurize the cylinder. As each  assembly was put on the carousel, the last one would be checked to see if the pressure had dropped below specification. If it had, that cylinder would be fitted with a different piston and tested again. The leakdown process was eliminated by Leisure dynamics at some point in time before I came to Cox, and I saw the carousel sitting there rusting away next to the glow plug element winding machine.  See Picture below of Leroy talking with one of the girls at the leakdown testing area. Note the huge pile of cases dumped in front of the pre-fitted .049 piston cylinder assemblies. The station for checking crankcase squareness was next to the leakdown testing, and you can see both Babe Bee and TD cases in the pile.