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).
Valve spring poundages and weakening after a 20,000-mile road test in France.
| Identifier | ExFiles\Box 91\4\ scan0279 | |
| Date | 4th October 1935 | |
| SPECTRECodename for Phantom III ⑤ UNIT VALVE SPRINGS AFTER 20,000 MILES ROAD TEST IN FRANCE Drg. HS.{Lord Ernest Hives - Chair}1827/B Drg. { Outer Spring = 43.8 LBS with Valve Fully Open. { Inner Spring = 21.2 LBS " " " " ACTUAL POUNDAGES OF SPRINGS. VALVE | INNER | OUTER | VALVE | INNER | OUTER No 1 | 20½ | 40¼ | No 13 | 20½ | 40¼ 2 | 19½ | 39¾ | 14 | 19¼ | 39¼ 3 | 20½ | 38½ | 15 | 19¾ | 39 4 | 20½ | 37 | 16 | 19 | 38¾ 5 | 19 | 38¾ | 17 | 20½ | 39½ 6 | 21 | 38½ | 18 | 20¼ | 38 7 | 19 | 36¼ | 19 | 20¼ | 38¼ 8 | 20 | 38¼ | 20 | 20¼ | 38 9 | 19½ | 39 | 21 | 19¼ | 39 10 | 20 | 39¼ | 22 | 19¾ | 39½ 11 | 20¼ | 41¾ | 23 | 20 | 38 12 | 20 | 40½ | 24 | 19¼ | 38¼ AVERAGE WEAKENING OF OUTER SPRINGS = 4 LBS " " INNER SPRINGS = 1.75 LBS ROLLS-ROYCE, LTD PRINT ROOM OCT 5 1935 DERK | ||