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).
Report page discussing brake temperatures and lining wear, including a description and diagram of a Buick brake drum.
| Identifier | ExFiles\Box 120\1\ scan0306 | |
| Date | 28th February 1941 | |
| front and rear temperatures on the Comet should be greater than on the Cresta, at fairly high speeds. It should be mentioned that the front/rear braking ratio on the Oresta was definitely high. A more usual figure like 1.3 would increase the temperature difference between front and rear drums. Neither the front nor the rear linings on the Cresta have been burned out due to normal driving. During the writer's experience of the Comet the fronts had always the same VG.90 linings fitted, while the rears had three sets of BZ and RU which, it is believed, are not so good for withstanding high temperatures. We illustrate the effect of temperature on lining wear by reproducing two curves, Figures 7 & 8. The first is from a report by C.G. Williams in 1931, and the second is a more recent curve for Ferodo M.R. in which it can be seen that although the wear does not increase quite so rapidly on the steep portion of the curve as in Figure 7, yet the lower parts of the two curves are almost identical in shape. It is clear from these two curves that the rate of wear at 200° C. is three times that at 100° C., while at 250° C. it is twice as fast again. The importance of these facts need not be stressed. TESTS ON THE BUICK "CENTURY" 8. ======================== DESCRIPTION OF DRUMS. Figure C. shows the drum and hub. The rim is of cast iron, as is the hub, and the back plate is of steel 0.100" thick, and is fitted to the rim by means of tabs round the outside which fit in slots in the rim and are turned over on the inside. The back plate is fitted to the hub with large rivets. The rubbing surface is 12.000" diameter and the linings 2.000" wide. The drum weighs 18.75 lbs. complete with hub, both ball bearings and oil seal. [DIAGRAM TEXT] 2.500 12.000 DIA FIG. C. BUICK BRAKE DRUM. | ||