From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Observations on Opel's manufacturing processes, integral body construction, and 2-litre 6-cylinder engine design.
| Identifier | ExFiles\Box 148\3\ scan0236 | |
| Date | 21th June 1937 | |
| -2- OPEL. This is Germany's largest motor car factory, and the production, engineered by General Motors, follows American practice closely, with new and up to date machine tools and assembly and conveyor equipment. We saw all the stages in the manufacture of the integral body and frame on the small Opel car and were impressed by the apparent lightness and rigidity of the resulting structure. On one of the models the top of the dash is moved back to form the instrument panel, and all instruments are detachable from the engine side. This eliminates the necessity for making gastight those points at which cables, wires, tubes, etc., usually pass through the dash. From our point of view the most interesting Opel engine is the new 2-litre 6 cylinder now in production. The crankcase and cylinder construction are similar to the Chevrolet, with equal spaces of about 3/8" between all cylinder bores. The crankshaft bearings are hardened by the Shorter process. Bearing shells are steel, about .048 gauge, copper plated, and with a very thin lining of white metal (approx. .010 - .020"), finished by broaching. Endwise location of the crankshaft is taken from No.2 main bearing cap only. For this purpose a strip of white metal is dovetailed (cast) into the cap on each side, there being no flanges on any of the bearing shells. Distributor and oil pump are driven from one inclined shaft at right angles to the camshaft, and another drive with die cast body is taken from the camshaft presumably for a rev-counter. Barrel tappets and push rods are similar to Chevrolet construction, but no tappet spring is used. Camshaft drive is by fabroil gear with teeth rough hobbed and finish shaped about 8 or 9 D.P. Short and apparently high rate valve springs with variable spaced coils are used. This results in shorter rocker pedestals and compact rocker gear generally more in line with our own practice than with current American Design. The valve springs were plated. (Cont'd) | ||