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).
Letter from Cadillac discussing front axle geometry, radiator caps, and testing rigs.
| Identifier | ExFiles\Box 170\2\ img131 | |
| Date | 15th March 1932 | |
| CADILLAC MOTOR CAR COMPANY DETROIT, MICHIGAN CADILLAC AND LASALLE MOTOR CARS March 15, 1932. Mr. E.{Mr Elliott - Chief Engineer} W. Hives, Rolls Royce, Limited, Derby, England. Dear Hs.{Lord Ernest Hives - Chair}: Thank you for the print of the radiator filler cap with steam seal. How much pressure do you allow? Thank Mr. Sykes also for sketch of jiggling rig. Have you a photo showing this being used to break up fabric couplings? I should like this very much as well as a photo of your scheme for fatigue-testing half-scale models of cranks. Rm.{William Robotham - Chief Engineer} asked for geometry particulars on front axles (in connection with a steering print which I sent him). These particulars are:- HELIX ANGLE 7º 11" Castor - 2-3/4º. Wheel angle (front view)- 1-1/2º King pin angle (pivot) front view - 7-3/4º King pin to wheel plane at wheel center - 3-1/2" King pin ¢ to wheel plane at ground - 1". You notice that it is quite "center point". It is remarkable that nearly all American cars went from vertical pins and offset to sloping pins and centerpoint, with the change to front brakes and balloons, at the same time as most European cars went in the opposite direction. Why is this do you think? I think it is just a matter of the other fellow's pasture looking greener. The king pins are on cup and cone ball thrusts top and bottom and are supposed to be frictionless. About 80 lbs ins of friction are added at the tie rods ends and the steering gear itself is of low efficiency both driving and driven. | ||