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 requirements for adapting a single-cylinder Bentley engine head for testing various compression ratios and throat sizes.
| Identifier | ExFiles\Box 134\1\ scan0147 | |
| Date | 25th March 1939 | |
| 1129 To By/Ald.{F. Allwood - Experimental Design} Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards}3/JH.25.3.39. Single Cylinder Bentley. We attach herewith a sketch of the EXS.1383 B.60 head showing how this may be adapted to accommodate three compression ratios and a selection of throat sizes. It was hoped to carry out this job on a main engine, but as the pattern has been broken up, we shall be obliged to do it on the 3.500" bore single cylinder unit, this head may however be made from scratch and the principal requirements are - (1) A throat as small as possible to start with but incorporating sufficient metal to allow of its being increased to the optimum value consistent with a reasonable compression ratio. (2) Sufficient metal on the base of the cylinder to allow machining this away to give various compression ratios with a selection of throat sizes. (3) Extended valve seat insert which will allow of machining away, without its being necessary to replace the seat each time. (4) Combination of inlet valve and distance pieces to allow the same inlet valve to be used for all tests. The general scheme will be seen by an examination of the sketch herewith. Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards} | ||