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).
Test report from Brooklands on axle and carburettor performance.
| Identifier | ExFiles\Box 29\3\ Scan174 | |
| Date | 13th September 1927 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. 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} OY. Y988 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG13.9.27. BROOKLANDS TESTS. X5774 X5771 We carried out further tests with a 17-tooth axle on the track. Additionally we had intended to employ a Claudel carburetter giving us some 20 clutch HP. more than the standard, unfortunately, when we tried this carburetter on the track, it would not function at all satisfactorily above 2600 r.p.m. so that we had to abandon it and revert to the standard. The conditions for the test were very poor for high lap speeds, a strong wind blowing directly up the railway straight. While therefore the results are quite satisfactory for comparing the various windage features of the car under these conditions, we consider that the figure of 1.4 m.p.h. given as the increase in speed due to a 17-tooth axle is somewhat misleading, as the tests due-to-a-17-tooth-axle-is a week ago carried out on the 16-tooth axle were under ideal conditions. Actually we believe that under similar conditions the 17-tooth axle should give an increase in speed of about 3 m.p.h. The car ran astonishingly well throughout the test which in all consisted of over 100 miles 'all out'. There was no sign of running after switching off, and the engine ticked over sweetly except where interrupted by the autovac which of course functions furiously after any prolonged burst of speed. The effect of the spare wheel and tail was very pronounced. The car did not hold the track nearly so well contd :- | ||