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 changes for Unit No. 21 (L.H. Chassis 25-MX) parts after a 25,000-mile test, comparing previous and revised specifications.
| Identifier | ExFiles\Box 169\1\ img201 | |
| Date | 26th November 1931 | |
| To Messrs. from RHC{R. H. Coverley - Production Engineer}/WSC.{W. S. Cassel} UNIT NO.21. (L.H. Chassis 25-MX.{John H Maddocks - Chief Proving Officer}) Engine and Chassis parts dismantled after 25,000 Miles Test for examination. Erected to previous specification incorporating the following.. PASSED TO TEST 21.11.31. Previous Specification. Crankcase & Bearings to Drg. A.79019. 1-set Bearings A.78763-70 1-A.78560 Centre Main Bearing Cap - Removed - Cracked. Connecting Rods to Drg. LeC.2736. A.79360 Big End Bearings Removed. Pistons to Drg. A.79533. 1-A.82041 Long Skirt Pistons Removed. Water Pump to Drg. A.79093. A.80365 Rotor - removed due to wear. Spring Drive to Drg. A.79915. (Low Inertia.) Revised Specification. Crankcase & Bearings to Drg. A.79019. New Set Main Bearings - A.78763-4-5-6-7-8-9-704 (Whitemetal) New Centre Bearing Cap A.78560. Connecting Rods to Drg. LeC.2736. New set Big End Bearings and Liners A.79360-1 (Whitemetal) Pistons to Drg. A.79533. 1-New A.82041 Long Skirt Piston. Water Pump to Drg. A.79093. New Rotor A.80365. Spring Drive to Drg. A.79915. (Low Inertia.) Damping Friction Load set at 16 lbs at 17 1/2 Rad; Load on Driving Springs.- 23 lbs at 17 1/2 Rad: -cont'd- | ||