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).
Performance upgrades for the 20 HP model, including fitting a cut-out and high compression pistons.
| Identifier | ExFiles\Box 47\2\ Scan193 | |
| Date | 2nd December 1929 | |
| W/S. C. From HS.{Lord Ernest Hives - Chair} X4117. HS{Lord Ernest Hives - Chair}2./MJ.2.12.29. 20 HP. Replying to C6/C29.11.29. In the case of a customer who requires better performance from the 20 HP, we should recommend fitting cut-out and also fitting high compression pistons. Since we demonstrated to you the high compression 20HP in London, we have proved that we can with the high compression reduce the ignition time without loss of power. This has the effect of reducing the detonation which was complained of. To fit new pistons to a 20 HP. car is a relatively cheap job. The cut-out should not be expensive if we can use up the present silencer which is fitted to this customer's car on production. To fit the cut-out to a 20 HP. means a new silencer and the necessary controls. With the above alterations the maximum speed would be increased approximately 5 m.p.h. with improved acceleration. HS.{Lord Ernest Hives - Chair} | ||