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).
Specifications and settings for a PFR.II clutch plate.
| Identifier | ExFiles\Box 169\4\ img183 | |
| Date | 19th January 1933 | |
| 3. PFR.II. CLUTCH PLATE. Damping set to 33 ft. lbs. 88 lbs. required to give maximum movement. spring pressure therefore 55 lbs. | ||