Pittman DC-85, 85A and 85X
Photos courtesy Bob Steere
The DC-85 series motors were, in a word, LARGE. At 1-5/8" long, 1-1/16" tall (even when laid down flat on it's side) and weighing 4-1/2 ounces all by itself, Pittman's DC-85 was among the largest and heaviest motors slot racers would ever use. This was not a motor for a road car; it found it's place among the ranks of the drag racers.
Originally the DC-85 was developed for model trains, so with its 12 volt windings it operated at no more than 9,200 RPM, but generated twice the horsepower of a DC-65.
Success in the drag racing venue prompted Pittman to introduce a six volt version in 1963, which they dubbed the DC-85A. It had 20% more RPM and 30% more horsepower than its predecessor; the almost inevitable result was that at the drag strip this motor was very nearly unbeatable in every class:
As a side note, check who won the Stock Class in Division One (with a DC-85A of course).
At the end of 1963 Pittman introduced yet another new version of this spectacularly successful motor, which they called the DC-85X. This new version however may have been no more than a name change. The DC-85X is also a six volt motor, has the same number of magnet field laminations as the DC-85A-6, and in every other visible way appears to be identical to the DC-85A-6.
For more information about the DC-85X click here.
In the middle of 1965, Pittman made another change; they discontinued the DC-85 series, and replaced it with (or perhaps just renamed it) the DC-84 series, as evidenced on page 91 of the 1966 Auto World catalog:
