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).
Design of future 6-cylinder car engines, including materials, insulation, and transmission options.
| Identifier | WestWitteringFiles\V\March1931-September1931\ Scan299 | |
| Date | 6th July 1931 | |
| FROM R.{Sir Henry Royce} C. to HS.{Lord Ernest Hives - Chair} C. to DA.{Bernard Day - Chassis Design} [Handwritten: Confidential] ORIGINAL [Handwritten numbers] Y5770. X7770. X399S. THE FUTURE CAR ENGINES. It is now agreed and understood that our two smaller [handwritten above: 99S] models shall have a 6 cyl. engine. I am arranging that the 16HP engine shall be an exact replica of the 28HP. (on a smaller scale.) We are taking great care that the 28HP. shall be an up-to-date and lasting design suitable for making as a very light engine in aluminium, or a less light, and perhaps cheaper engine, in cast iron. In either case it should have long life and be capable of repairs, features one thinks would help sales and be distinct from U.S.A. practice. It is now distinctly realised that a 6 cyl. engine if it runs at high speeds (such as 3000 RPM.) must be insulated (mechanically) torsionally from the frame, even more effectively than in P. 1., and it cannot [handwritten insert: therefore] help the stiffness of the complete motorcar from twisting its frame by the effects of the road surface, but its inertia can be used to damp the torsional vibrations of the frame by the use of our torque reaction dampers. (This forms what we call our complete conversion scheme for P. 2. which should be used instead of removing the rear feet only, of which I do not approve.) No engine so far is reported to be entirely good at very high engine revs., and since we must have a low gear for sufficient acceleration we are forced into a silent 3rd. or double top, both of which we have in hand. They must have an easy or certain change; this we are embodying in both the gears we are making. We have been obliged to copy the synchro mesh used by the Americans as we have not found anything up to the present so simple and practical that will just meet the requirements of the smaller cars. The larger car may justify something superior and more comparable with the Wilson/Lanchester gear without its delicacy of constitution. This we are trying in our epicyclic double top which is now [handwritten insert: being] operated by friction clutch and brake controlled by oil pressure. There seems little doubt that our engines give the best low speed torque of any, which I pointed out recently in comparing Bentley/Ricardo with RR. [handwritten: Further notes on this subject to follow.] [Handwritten signature: R] | ||