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 Packard Motor Car Company providing spring rate and shock absorber information for the Super Eight model.
| Identifier | ExFiles\Box 127\1\ scan0181 | |
| Date | 13th July 1934 | |
| L.E.S. x435 PACKARD MOTOR CAR COMPANY DETROIT MICHIGAN July 13, 1934. Mr. W. A.{Mr Adams} Robotham, Rolls-Royce, Limited, Derby, England. Dear Mr. Robotham: Reference: Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}19/K W. I am awfully sorry this letter became mislaid, but if it is not too late the information you asked for is here given: I presume that you are referring to the Packard Super Eight and probably refer also to the five-passenger sedan with the standard equipment - that is, the tire on the rear and not in front fender wells. We have been using front spring rates at 300 lbs. per inch with rear spring rates of 145 lbs. per inch and these rates being measured with the springs at their normal loaded height. The static deflection for the front and rear is, respectively 3.25 inches and 7.04 inches. I do not have data pertaining to shock absorber loadings. It is not customary for us to determine these loadings by measurements. I should rather state that we use Delco Products Corporation 1-3/4" shock absorbers with valving as shown on the appended sheet. I hope this will give you the information you desire and if there is anything else, please do not hesitate to say so. I might add, in connection with springing, that we use metal covers with graphite oil lubrication, which is very efficient in maintaining constant friction. Our springs also are made of flat rolled spring stock. That is to say that the stock is not rolled with the usual concave surface. Furthermore, the spring leaves have rolled ends. | ||