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).
Proposed improvements for the 25 HP car, based on testing and competitive analysis.
| Identifier | ExFiles\Box 181\M13\M13.2\ img109 | |
| Date | 1st October 1931 | |
| To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to By.{R.W. Bailey - Chief Engineer} 25 HP. X5770 When Sg.{Arthur F. Sidgreaves - MD} was at Derby yesterday it was agreed that we should proceed preparing 1S-G4 with the new parts which it is hoped to incorporate in the 25 HP., so that the car could be run for 10,000 miles in France as soon as possible. The chief items we propose to fit to this car are - Diamond engine mounting. Sheet metal cross member. Cantilever battery box support. Lower radiator. Rivetless bonnet, flip flap shutters. Modified exhaust system. Easy change gearbox. 3" dia propshaft. Improved shock absorbers. The engine will have - Balance weights 6/8 scheme. Larger dia. crankpin and rods to suit. Flywheel with thin back plate. High compression pistons. Camshaft to give high lift to valves. Modified valve springs. We expect, when this car is finished, it will show a definite advance over the present 25 HP. that we are selling, in fact, we think it will represent one of the biggest changes we have made in the small sized car. From the tests we have had on other makes of cars and the comments we have had against the present 20/25 HP. these improvements embodied in the production cars are urgently required. We must get these improvements embodied in the production cars. Mr. Geoffrey Smith, of the Autocar, who has had several 25 HP. cars, has now sold his R.R. He told me the other day that he had taken a 20 HP. Sunbeam on a continental tour, and was emphatic that the engine was better than the R.R. also that the performance was better. He had taken it over the same country as he had previously taken the 25 HP. R.R. and he made a point of the fact that whereas he had had continuous trouble with boiling with the R.R. car, he had had no trouble with the Sunbeam. Fortunately, the parts we are committed to on the | ||