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).
Table comparing engine components and proposed modifications for Bentley and High Power units.
| Identifier | ExFiles\Box 111\2\ scan0230 | |
| Date | 26th August 1937 | |
| -3- 26.8.37. TITLE | REMARKS | BENTLEY | H'POWER. Idler Gear. | This is being omitted on the High Power Unit. | 2 | - Calorstat. | No change. | 1 1/4 | 1 1/4 Inlet Manifold etc. | Single carburettor, with six ports. | 6 | 6 Exhaust Manifold | Four port type. | 7 1/2 | 10 Washers etc. | No change. | 1/4 | 1/4 Carburettor | Single carburettor, assumed of 25/30 type. | 8 1/2 | 5 1/4 Air Intake | 25/30 | 3 1/4 | 2 Air Silencer. | 25/30 | 6 1/2 | 5 1/4 Pipes etc. and Coupling of carbs. | 25/30 | 2 1/4 | - Petrol Pump Filter & piping | No Change. | 7 1/2 | 7 1/2 Controls etc. | It is suggested the cable controls be used instead of the present system of levers. | 3 1/2 | 1 1/2 Engine Mountings. | The complete engine suspension is being modified but no great change in weight is anticipated. | 20 1/2 | 20 1/2 Torque reaction. Dampers. | These are to be changed but the weight is assumed the same. | 2 3/4 | 2 3/4 Mounting of change speed gate. | To be omitted. | 1/4 | - Clutch & Controls. | No change. | 31 1/4 | 31 1/4 | ||