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).
Summary of a letter discussing engine design schemes, vibrations, and suggestions for future engine development.
| Identifier | ExFiles\Box 137\4\ scan0187 | |
| Date | 29th January 1931 | |
| SG.{Arthur F. Sidgreaves - MD} FROM R.{Sir Henry Royce} SECRET AND R1/M29.1.31. (At Le CanadelHenry Royce's French residence) CONFIDENTIAL C. to Lord Wargrave. X.7770. C. to Mr. Claremont. X.5770. C. to LHS.{Lord Herbert Scott} WOR.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} P. 2. & JAPAN ETC. X.634. C. to HS.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} RG.{Mr Rowledge} DA.{Bernard Day - Chassis Design} The summary of this letter (if one has not time to read it all) is as follows: (1) I am more content with the design schemes for Japan 3. (2) That booming vibrations and several other car troubles have been brought on by increased engine revs. and car speeds, and road wheel revs. due to greater available engine power, lower gears, (including smaller wheels,) better roads (- i.e. including high speed wide by-pass roads), balloon tyres, etc. (3) That car engines more often now than formerly run at very high revs. (by 2) and too slowly (stop lights etc) by top gear work, the reason for double top increasing daily. (4) That couples in 6 cyl. engines cannot be completely balanced and run at very high speeds, suggesting that 3000 is perhaps too fast for an engine of P. 2. size, and certainly 4000 is. (5) That balance weights can be used on 12 cyl. engines, and also owing to this only needing very light flywheel, this is the high speed engine, because it is an engine capable of greater speed range without as far as we can forsee, running into objectionable symptoms, because: (a) The flywheel need be clutch only and so light that its period can be above 4000. (b) The couples of the crankshaft can be counterbalanced up to, or nearly completely. (c) As we are building camshaft drive and starter drive are always positive - does not over-run or rattle. (d) That torque reactions and over-run vibrations are imperceptible. I suggest that we waste no precious time but push on as quickly as possible with double 28HP., but perhaps 4.5" stroke instead of 5", using all 28HP. parts possible - i.e. head, valves and their fittings, pistons and pins, no alteration to chassis. This should give more body room - i.e. passengers more central. This should be our reply to Bentley for the next Show, and well over 8 litres if we wish real luxury carriage also. (1) | ||