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).
Comparing the performance of a 20 HP Sunbeam car against a 20 HP model.
| Identifier | WestWitteringFiles\L\2April1924-June1924\ Scan18 | |
| Date | 12th June 1924 | |
| R.E. 493A (20H) (D.A. 652 20-5-24) J.H.D. EXPERIMENTAL REPORT. ORIGINAL Expl. No. 446 REF: Hs{Lord Ernest Hives - Chair}3/LG12.6.24. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. BJ. PN.{Mr Northey} WOR.{Arthur Wormald - General Works Manager} 20 HP. SUNBEAM CAR. I had an opportunity of testing a new 20 HP. Sunbeam car. It had only been delivered from the makers about a week. It was one of the latest 20 HP. with 4-speed gearbox, and increased wheel base. It was fitted with a Saloon type body. The total weight of the car without passengers was 36 1/2 cwts. We tested the car over a known route and compared it with the RR. 20 HP. car fitted with a Saloon type body. The 20 HP. RR. car weighed 30 cwts. without passengers. The performance on a timed hill was :- The RR. climbed on top gear in 1 min. 55 secs. The Sunbeam took 2 mins. 15 secs. and it was necessary to change into 3rd. gear. On the level the maximum speed of the Sunbeam was 54 m.p.h. The RR. 20 HP. max. speed on the level was 58 M.P.H. The pick up and acceleration of the Sunbeam was poor. If the carburetter was opened fully, at low speeds the engine would flop out. The impression one got when driving the car was that it was spoilt by the heavy weight and big body. The car was fitted with balloon tyres and the riding was extremely nice. It had four wheel brakes operated by direct pedal pressure only, with Perrot type self- contd:- | ||