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).
Weight comparison of brake drums, engine, and clutch components between S.S. and Bentley vehicles.
| Identifier | ExFiles\Box 126\5\ scan0078 | |
| Date | 30th August 1938 | |
| -3- The weight of the respective drums are:- S.S. 4 drums 83 lbs. Bentley 4 drums 57 lbs. 3 ozs. The Bentley servo weighs 21 lbs. 2½ ozs. The Back plates and brake carrier plates on the S.S. weigh approx. 35 lbs. 15 ozs. whereas those on the Bentley weigh 19 lbs. 6 ozs. The Bentley weight, is however, greatly increased by the equalisers and operating mechanism, (other than the servo) the actuating shafts and levers on the rear axle alone weighing 14 lbs. 2 ozs. Engine & Clutch. S.S. Engine & Clutch Weight 597 lbs. 7¼ ozs. Bentley. Engine & Clutch Weight 632 lbs. ¾ ozs. The following engine weights show where weight is lost and gained on the S.S. and Bentley engines:- | | S.S. | Bentley. | | |---|---|---|---| | Cylinder block and crank-case | 159 - 0 | 128 - 5 | S.S. shorter monobloc B. alum c/case. | | Cylinder head | 74 - 3 | 66 - 8 | S.S. head deeper. | | Crankshaft | 55 - 8 | 53 - 8 | | | Flywheel | 30 - 7 | 50 - 5½ | | | Lower half | 17 - 11 | 25 - 0 | B. deeper, longer & baffled. | | Timing case | 2 - 6¼ | 5 - 10 | S.S. pressing, B. alum casting. | | Exhaust manifold | 17 - 3 | 7 - 6 | S.S. six port, twin branch. B. 3 port. | | Starter | 20 - 3 | 23 - 1 | | | Dynamo | 21 - 6 | 24 - 10 | | | Water pump & drive | 4 - 10¼ | 10 - 6¾ | | | Spring drive | | 14 - 10¾ | | | Fan and drive | 4 - 14 | 7 - 10 | | | Engine Mounting | 15 - 9 | 20 - 9½ | | | ||