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).
Future car engine design, comparing 6-cylinder engines with 8 and 12-cylinder Vee engines.
| Identifier | ExFiles\Box 65a\3\ scan0282 | |
| Date | 18th April 1931 | |
| E.{Mr Elliott - Chief Engineer} HS.{Lord Ernest Hives - Chair} ) FROM R.{Sir Henry Royce} RG.{Mr Rowledge} BY.{R.W. Bailey - Chief Engineer} ) (At Le CanadelHenry Royce's French residence.) SECRET. X7770 R1/M18.4.31. C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} C. to DA.{Bernard Day - Chassis Design} LHS.{Lord Herbert Scott} C. to MR. CLAREMONT. CAR ENGINES - THE FUTURE INCLUDING J.{Mr Johnson W.M.} 3. & P. 3. X. 5770. X. 7770. X. 3993. In our J.{Mr Johnson W.M.} 3. engine and our future car engines we must make some drastic changes so that they are entirely smoother. So called rough engines must be something of the past and I cannot agree to depending on the body for any torsional stiffness of the frame, so the engine must be smooth enough to help. It is also pretty certain that bodies should be insulated from the frame so that road vibrations such as met with on wooden pavement does not boom them so badly. Now with 6 cyls. we can I believe - (a) quite cure the flywheel whirl. (b) and we can nearly eliminate the torsion period if we put the flywheel in the middle of the crankshaft. (c) but we cannot hope to avoid the reactions from the torque, and as these are all important in top gear town carriage work I have decided not to recommend our Co. to spend money on production tools and patterns for 6 cyl. engines for our work. It is also certain that we cannot have a long engine, and if we could we should be in trouble with want of stiffness of crankshaft or chamber, and it is heavy and costly engine to make. So we come back to our friend the Vee engine as the only suitable one, either as 8 or 12 cyls., and I can see no reason why an 8 Vee should not be used for our smaller model and 12 cyls. of the same bore and stroke for the larger model. With 3" bore it gives us 3 X 3 X .4 X 8 = 43.2 HP.? with stroke 4.5 to 5". As far as I have examined it there is little advantage in the Ricardo head at vslow speeds and as regards costs and good arrangement of a Vee engine our own scheme is much the better. If it is decided that we must make the 6 cyl. then the objection to Ricardo's engine on the score of convenience is less, but one still feels that the complete overhead job as we make it is preferable from a construction point of view, and cost. | ||