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 tests for a 27 Ex. Car at Brooklands, showing acceleration, speed, and valve timing.
| Identifier | ExFiles\Box 92\2\ scan0154 | |
| Date | 5th October 1931 | |
| 27 Ex. CAR. PERFORMANCE TESTS ON BROOKLANDS. 5TH OCT. 1931 L.E.C. 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 50 LBS/D") 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. I.O. 2.2° E.C. 12.7° E.O. 56.6° B.D.C. I.C. 59.7° ACCELERATION. TOP GEAR. ROAD SPEED (M.P.H.) TIME (SECS.) | ||