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 tests conducted with twin Solex carburettors on a Phantom II vehicle.
| Identifier | ExFiles\Box 121\2\ scan0138 | |
| Date | 22th January 1930 guessed | |
| To Hs.{Lord Ernest Hives - Chair} From ACL. x3603. SUMMARY OF TESTS WITH TWIN CARBURETTERS ON PHANTOM II. Our tests with Twin Solex carburettors on Phantom II show that the improvement so obtained is greater than the improvement of Phantom II over Phantom I. This carburetter gives approximately the same maximum power but the performance at the lower speed is greatly improved. From the Solex we get a maximum gain at approx. 39 miles/hour, which amounts to about 17% at the road wheels. The gain is approximately equal to increasing the BORE of the engine ¼" when using standard carburettors. Sir Henry Segrave says that the standard Phantom II is not as good as the Hispano for 'snap' acceleration and 'get away'. We know from tests that Phantom II does not equal the Hispano. With the Solex carburetter we can equal the Hispano results and the 'snap' acceleration and response is much more instantaneous. On one of our test hills where the maximum speed is 35 miles/hour we can reduce the time to climb from 64 to 55 secs. The twin carburetter is the simplest way we know of increasing our performance at low speeds. We get similar results on the 20/25 HP. fitted with Twin carburettors, to as we do on Phantom II. Hs{Lord Ernest Hives - Chair}/ACL. | ||