I worked at Cox in customer service during 1980 doing engine and radio repairs. Dale Kirn, Roger Theobold and Kit McNorgan trained us on how to service the engines. We had service parts dating back to the 1950s and often built older "Hopper" series engines using new old stock parts left over from the original factory that was on Pointsetta St., in Santa Ana. We also had three test booths we used to run-in and test customers engines. In our spare time we would hand fit and build engines as replacements for customers, mainly because we had better old stock parts in customer service than the ones being produced in the factory that reflected the cost cutting measures implemented by Leisure Dynamics management. In this way, we were assured of the customer getting a good engine because it was hand bui lt and test run before they recieved it.

Some TD tips: Stock venturi required for suction (non-bladder set-up) We used a Uni-flow tank when using backplate pressure, basically the vent (line to the pressure tap) goes to the bottom or the tank. Best performance is with a bladder. Shims are to "synch" the exhaust ports fore and aft so the transfers line up with the rotating crank, good for about 750 RPM. After shimming, check your deck height, you may need to remove a head gasket or two. If running high nitro, you need less compression, or TDs become very hard to needle consistantly and overheat. We added extra head gaskets when using 25% or more nitro.

The cylinders you see with two exhaust slits were done that way to save a machining step. The slits are cut first, then they are cut free in the next step to form the rectangular port. Under Leisure Dynamics, they eliminated cutting out the full port and left it with the two slits because it was not only cheaper, but also served to reduce problems with accidental fires. Most of the later Cox cylinders and pistons, even ones made at Cox Santa Ana (Warner St.) lack any taper, and althought they run fine and break in quickly, they wear out quickly. During 1979-80, under Dale Kirns direction, the tapers were put back on the TD .049 and a short run of about 800 engines were hand fit and assembled. These were some of the best TDs ever made by Cox and built by Kit McNorgan. The early thin wall cylinders are not as strong, and due the way they are tapered and fit, can take a long break-in. Despite what people have done, it is best to never swap pistons, epecially used ones into a used Cox cylinder. If you have a new piston, that is your best bet. The cylinder number indicates the port configuration on the .049 as follows: 1 is dual bypass, 2 is single bypass, 4 is TD. other numbers are for the cars and Medallion series.