| October/November 1987

Gray engine


While browsing through our copy of Motor Vehicles & Motors by Beaumont, we noted a discussion of various engine styles, and in particular the development of the 'double-inclined cylinder engine' which we now refer to as the V-type. It was invented by Daimler in Germany, and the original patent shows the air intake valve in the piston, as Daimler had done with his early single cylinder designs. The V-type engine was apparently not built under this design but originally was equipped with poppet valves. These were operated by a most unusual mechanism with a sliding piece in the cam grooves. The double-tracked cam was arranged so that the slider would alternately follow two different paths. Because of this arrangement the exhaust valve was operated only on alternate revolutions.

N. A. Otto, the inventor of the four-cycle engine seems to have concentrated most of his efforts on stationary design, while Daimler was preoccupied with fitting internal combustion engines to automotive purposes. In this he excelled, and was eminently successful in building small, lightweight, and high speed engines.

Gottlieb Daimler was born at Schorndorf, Germany in 1834 and died March 6, 1900.

This month's questions begin with:

22/10/1 Q. I need information on a David Bradley Tri-trac tractor made by Sears-Roebuck in the mid-1950's. Especially needed are belt sizes, but any other information will be appreciated. Harold R. Peabody, RFD 1, Box 112, 859 Riverside Drive, Augusta ME 04330.

A. We have limited data on the David Bradley line but nothing on this particular model. Anyone with this information, kindly contact Mr. Peabody.