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).
Specification table for identifying Long Clutches for various engines.
| Identifier | ExFiles\Box 130\3\ scan0134 | |
| Date | 9th November 1940 guessed | |
| 1110 re Long Clutches. In order to identify at sight the correct Long Clutches for various engines, the following information will be useful. | ENGINE. | | Colour of Thrust Springs | Nominal Poundage | Borg. and Beck. | | |---|---|---|---|---|---| | | | | | Spec. No | Drg. No. | |---|---|---|---|---|---| | 8 Cyl. 3¼ Bore. | 11" | Red. | 150/155 | BB.472. | 23000/2 | | 6 Cyl. 3¼ Bore. Heavy Car. (Wraith type) | 11" | Light Blue | 110/120 | BB.471. | 23000/2 | | 6 Cyl. 3¼ Bore. Light Car. (Bentley type) | 10" | Orange. | 125/135 | BB.460. | SK.31174/2 | | 6 Cyl. 3¼ Bore. (Ripple) | 10" | Light Blue | 110/120 | To follow | SK.31173/2 | | ||