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).
Comparison of 40/50 clutch spring specifications relative to 25 HP clutch slipping.
| Identifier | ExFiles\Box 13\7\ 07-page117 | |
| Date | 6th January 1932 | |
| Copy for files. X7480 6. 1. 32. X5480 40/50 CLUTCH SPRINGS. POSITION RELATIVE TO 25 HP CLUTCH SLIPPING. Drawing length of Clutch Spring. 4.100 " Rating " " 142 lbs. " Load in position. 220 lbs. Actual free length when springs have 3.990 been compressed a few times. Actual rating 162 lbs/1" Actual load when in Clutch Home 234 lbs. position i.e. spring length 2.550 or a deflection of 1.440" Actual clutch spring pressure on the 1372 lbs. 40/50 is 6 x 234 Actual ratio of 40/50 and 25 HP. 234/126 = 1.86 loads are Correct ratio allowing for difference 1.42 in max M.E.P. attained and different clutch mean raduis is Correct spring pressure for High 165 lbs. Compression Large Bore 25 HP car is Strongest springs available are 143 lbs. and it will be seen that these are badly needed. HS{Lord Ernest Hives - Chair}/Phun | ||