Analysis of increased brake leverage and comparison of hydraulic damper valve configurations.
| Identifier | ExFiles\Box 5a\3\ 03-page317 | |
| Date | 20th June 1933 guessed | |
| - 7 - place. This gives .375 more brake pedal movement before brake adjustment is needed. The leverage to the front brakes has been increased 34% to give more front braking. We have not found the extra braking to the front to give any detrimental results. In fact with all brakes in an offecient state, the car was steadier and was more under control, but there is a danger of the front becoming too effective, as we have experienced previously with no direct increase to the front. The increased braking to the front has resulted in increased wear. It was necessary to adjust them after 2000 miles. The last 1000 miles the leverage movement has increased .125. One notch of adjustment is equivalent to .375 movement of the lever. FRONT HYDRAULIC DAMPERS L.O.P.F.59671. Loads set. L.F.70 lbs R.F.70 lbs REAR HYDRAULIC DAMPERS L.O.P.F.50670. Loads set L.R.70 lbs R.R.70 lbs The hydraulic dampers as first fitted with .066 holes in the valves and 70 lbs load in conjunction with the low rating road springs gave soft springing and good road holding qualities up to a speed of 50 M.P.H. On a good surfaced road, above this speed the riding qualities were still good, but not sufficiently controlled for braking. There was no undue rolling of the car when cornering. To obviate the necessity of drilling the valves, a scheme of solid valves with washers .025 thick under the valves, to prevent the valves closing, giving approx. the same leakage were fitted. The result was that at low speeds the riding was slightly harder. In our opinion we do not believe it would be objected to. The riding and road holding qualities at speeds above fifty miles per hour was distinctly better. The difference being such, that on a certain road before altering the valves the rear floated up and down with the natural frequency of the springs, and the car did not hold the road at all well. With the non drilled valves the floating was definitely checked, the riding in the rear was not objectionable and the car was under control. There was less tendency of the rear axle to jagger when braking hard. We are of the opinion that the non drilled valves with a definate leak are the best proposition. | ||
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).