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).
Notes on the engine and chassis construction of Humboldt-Deutzmotoren and Opel vehicles.
| Identifier | ExFiles\Box 142\3\ scan0258 | |
| Date | 29th June 1937 | |
| -2- Humboldt - Deutzmotoren, A.G. (Cont'd). big end with a lead bronze upper half and a white metal lower half, particularly suited to the Diesel engine because of the high explosion pressures and low revolution speeds. One range of engines has an aluminium crankcase cum cylinder block construction to reduce weight. This firm possesses a very interesting museum, well worth seeing, of internal combustion engines from the earliest days to the present time. Opel. The chief point of interest here was naturally the production of cars where chassis and body are one unit built up of pressed steel parts welded together. One point of interest in this connection is that although the construction lends itself best to saloon cars, the drop head type of body is also made, and here extra reinforcement is added to the lower body-cum chassis rails to obtain the required strength. This seems to prove that in their sizes at least sufficient rigidity can be obtained from a structure composed of a number of light gauge steel pressings welded up into a unit, and the advantage they gain is reduction of height, the stiffness is obtained without having to use a very deep side member. Two questions whose answers would be very useful are; whether the construction is equally satisfactory for larger cars (the largest Opel is of 2½ litres capacity); and at what production volume the cost of the dies for such a construction can be justified. One interesting point on their six cylinder push-rod overhead-valve engine was the use of a steel pressing to close in the cylinder head in the neighbourhood of the sparking plugs and push rods. The difficulty of obtaining sufficient room for casting walls, plugs, and push rods led to the use of sparking plugs exposed to oil vapour on the Vauxhall 12 and 14 h.p. cars, the sparking plugs projecting from the water-jacketed part of the head into the push rod space, and the head then having an outer wall with a hole for each plug - these holes being closed by Bakelite cups fitting round the edge of the hole and secured to the plug central electrodes. The 25 h.p. Vauxhall has not the outer wall mentioned above, a horizontal valley going along the head at the height of the plugs and steel tubes being pressed in through the top and bottom flanges to enclose the push rods. The (Cont'd). | ||