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).
Performance and test data sheet for a Marmon car, detailing weight, gear ratios, acceleration, and dynamometer results.
| Identifier | ExFiles\Box 32\5\ Scan128 | |
| Date | 16th December 1920 | |
| G.FC X1692 16.12.20. X1692 PARTICULARS OF MARMON CAR. Weight complete with - Open-touring body (4-seater) 32 x 4½ Hayes wire wheels with Goodyear rims. Spare wheel carried at rear - Petrol Tank to hold 15 galls. Engine - 3 galls. of oil and 4 galls. of Water - Front 17 cwts. } Rear 18 cwts. } Total - 3920 lbs. Gear ratios - top direct 4.15 to 1 2nd. 6.861 to 1. 1st. 14. to 1 Reverse 18 to 1 1000 Engine revs: = 23.5 M.P.H. on the road. Petrol Cons: on road - 20 M.P.H. 18 18.25 M.P.G. 30 M.P.H. 16.75 16.75 [STAMP: EFC DEC 17 1920 RECEIVED] Acceleration. M.P.H. at start. | Distance Yds. | Secs. | M.P.H. finish. --------------------------------------------------------------- 10 | 528.3 | 32 | 20 | 528.3 | 30 | 55 30 | 528.3 | 25 | 62 40 | 528.3 | 22 | 63 Dynamometer Test. Eng. Revs. | Dyn: Revs. | Petrol. Pts. per Hr. | lbs. lifted. | HP. -------------------------------------------------------------------------- 500 | 350 | 13 | 118 | 14.76 750 | 525 | 19 | 128 | 23.82 1000 | 700 | 31 | 148 | 37.03 1250 | 875 | 39½ | 150 | 46.72 1500 | 1050 | 44 | 144 | 54.12 1750 | 1225 | 46½ | 137 | 59.99 2000 | 1400 | 50½ | 128 | 64.06 2250 | 1575 | 53½ | 121 | 68.13 2500 | 1750 | seized | | Clutch ease of changing - 1st. to 2nd. gear clings a bit - others all O.K. no double clutch required. No squeaks, picks up smooth - no jingling. Brakes. No jaggers - Foot Brake good but spongy. Side brake very poor. Contd. | ||