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).
The urgent need for a satisfactory aluminium piston design for repair cars.
| Identifier | ExFiles\Box 35\2\ scan 079 | |
| Date | 9th June 1919 | |
| X.2748 To BN.{W.O. Bentley / Mr Barrington} from R c.to CJ. EH. Wor.{Arthur Wormald - General Works Manager} EPC. COPY R3/G9.6.19. X.2748 RE PISTONS X.3559. It is of the utmost importance that we get a satisfactory design of aluminium piston for repair cars promptly My chief object in pressing this forward is that no form of piston has been entirely satisfactory, and in the endeavour to entirely avoid piston knocks, repair people have been driven to fitting cast iron pistons too tightly, and consequently they have seized, and stopped the car, sometimes permanently. Now my experience with aluminium pistons is that if customers are given to understand that it is impossible to entirely avoid slight knocks from the pistons while the engine is cold, the aluminium pistons are quite satisfactory, especially in the latter thick trunk form that has been adopted for the short connecting rods. With this piston we should have a better running engine, less trouble from detonation, slightly more power, that we could remove the balance weights from the crankshaft, which is desirable, that we could lighten the front flywheel, also desirable, that so resulting in reducing the weight on the front by nearly 1cwt. benefiting the steering and general running, and giving an increase for hill climbing of 2 1/2% through this saving of weight alone, but above all things, we have an end to the risk of galling the cylinders through over-tight cast iron pistons, which I am helpless to prevent repair and service stations from fitting. R.{Sir Henry Royce} | ||