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).
Key engine design features for longevity and smoothness, and the factors causing increased engine speeds.
| Identifier | ExFiles\Box 14\2\ Scan067 | |
| Date | 1st November 1929 | |
| -16- Hs{Lord Ernest Hives - Chair}/Tan5/ADA.11.29..contd. GENERAL. All our evidence, from theory, from test and from watching closely the changes in other cars, goes to prove the importance of the following three features to give long life and smoothness at the engine speeds usual nowadays. (1) Heavy crankshaft, stiff laterally and torsionally. (2) Balance weights. (3) Stiff crankcase. Practically, every new car produced nowadays, incorporates one or more of these three features. They are standard practice on racing cars, and since we propose to run our cars at almost racing car piston speeds, we should be prepared to try some of their ideas. However, even if it be argued that owing to rubber engine feet, etc. smoothness may not necessarily be improved when these things are done, we think there remains sufficient reasons, purely from the point of view of long life of parts, for doing some experiments along the above lines. During the last year or so, engine speeds have increased enormously. Car speeds have increased because of:- (a) Increased acceleration. (b) Better roads. (c) Better brakes. On top of this, engine speeds have increased still further due to :- (a) Lower Axle ratios. (b) Rubber engine mountings encouraging use of the gears. | ||