Performance test report for a 27 Ex car at Brooklands, detailing specifications, lap speeds, and top gear acceleration.
| Identifier | ExFiles\Box 155\1\ scan0004 | |
| Date | 5th October 1931 | |
| 27 Ex CAR. PERFORMANCE TESTS ON BROOKLANDS 5TH OCT. 1931 LeC.2905/6 R.R. TWIN CHOKE CARBURETTER. (MODIFIED TO CURE FLOODING ON CORNERS) WITH AIR SILENCER. (EXPTL.) 114° W.W. CAMSHAFT (E.82448) COMPRESSION RATIO 4·8 : 1 REAR AXLE RATIO STANDARD (3·727:1) CAR WEIGHT COMPLETE 46 CWT. 2 QRS. 21" RACING TYRES. (EFFECTIVE CIRCUMFERENCE AT 50LBS/□") PRESSURE 105·75" = 599 REVS/MILE. ENGINE REVS/MIN. AT 60 M.P.H. TOP GEAR = 2233 ALL RESULTS WITH CUT-OUT OPEN BEST LAP SPEED 87·1 M.P.H. HALF MILE 89·11 M.P.H. } AGAINST STRONG HEAD WIND. MILE 87·38 M.P.H. VALVE TIMING .013" CL'NCE. Diagram: 102.2°, E.C. 12.7°, E.O. 56.6°, B.D.C., I.C. 59.7° Graph: ACCELERATION. TOP GEAR. Y-Axis: ROAD SPEED (M.P.H.) X-Axis: TIME (SECS.) | ||
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).