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 of a new Bentley six-cylinder engine with a Ricardo patent head.
| Identifier | ExFiles\Box 21\2\ Scan084 | |
| Date | 19th March 1931 | |
| To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to Sg.{Arthur F. Sidgreaves - MD} c. to Dr. c. to E.{Mr Elliott - Chief Engineer} 3805. Hs.{Lord Ernest Hives - Chair}2/MJ.19.3.31. CAR ENGINES. The new Bentley six cylinder four litre engine is fitted with the latest Ricardo patent head. A sketch of this head is attached. Ricardo holds the view that this is the most efficient form of combustion chamber that he has ever tried, taking into account power, rate of pressure rise, non-detonation, and costs. The new Bentley engine of 3.9 litres will give a maximum HP. of 120. The engine can be run with fixed ignition and is free from detonation. The proposed compression ratio is 5.5/1. Ricardo holds the view that this could be increased, if necessary. They are getting more power from this engine at 3.9 litres than the 4½ litre 4 overhead valve engine, with considerably less detonation. It is anticipated that the new Bentley car will be announced within the next few weeks. Hs.{Lord Ernest Hives - Chair} | ||