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).
Brooklands test results for a 12 G IV Close Coupled Four Seater car, comparing performance with different configurations.
| Identifier | ExFiles\Box 181\M9\ img013 | |
| Date | 14th August 1931 | |
| R.M. 28 12 G IV BROOKLANDS TEST 14/8/31 CLOSE COUPLED FOUR SEATER WT. 32.25 CWT TYRES 6" FORT DUNLOPS 19" RIMS. 60 MPH = 3000 R.P.M. AXLE RATIO 11 X 50 CONDITION OF CAR AND UNIT LAP TIME LAP SPEED 1) CAR IN STANDARD T SERIES CONDITION BUT WITH STRONGER VALVE SPRINGS WHICH SHOULD HAVE NO EFFECT AT THIS SPEED 2 MIN 31.4 SEC 65.78 MPH 2) AS 1 BUT S.U. CARB 2 MIN 26.4 SEC 67.57 MPH 3) ENGINE GIVING 80 B.H.P AS IN CURVE R.M 27. STD CARB. C.O. CLOSED P.II EX. SYSTEM 2 MIN 17 SEC 72.49 4) AS 3 BUT C.O OPEN 2 MIN 15.6 SEC 73.45 5) ENGINE GIVING 89 B.H.P AS IN CURVE R.M.27. S.U. CARB C.O. CLOSED 2 MIN 12.4 SEC 75.23 6) AS 5 BUT C.O. OPEN 2 MIN 10 SEC 76.62 AIR TEMP 19° C TOP WATER TEMP PLAIN BONNET 82° C LOUVRED - 74° C PETROL CONS: 160 MILES DERBY - BROOKLANDS R.R CARB 21 M.P.G. S.U. CARB 20.0 M.P.G 19 G IV 10,000 MILES CAR LAP SPEED 63.7 M.P.H STAMPED: ROLLS-ROYCE LTD. PRINT ROOM 17 AUG 31 | ||