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).
Progress report on the B.60 engine test, comparing novel modifications to the conventional 4¼-litre engine.
| Identifier | ExFiles\Box 134\2\ scan0186 | |
| Date | 9th February 1939 | |
| To By.{R.W. Bailey - Chief Engineer} from RM.{William Robotham - Chief Engineer} c. HS.{Lord Ernest Hives - Chair} c. Da.{Bernard Day - Chassis Design} c. RHC.{R. H. Coverley - Production Engineer} c. HPS.{Horace Percy Smith - Experimental Factory Mgr} c. Day/Jnr.{Charles L. Jenner} c. Day/MOS. HIGH POWER ENGINES. In reading the attached report it must be remembered that we have had a B.60 on test for just over four months. Half of this was largely occupied in rectifying installation, fitting and other minor errors. The departures from the existing 4¼-litre engine practice may be divided into two sections (1) A novel combustion chamber and valve arrangement. (2) A number of other modifications all of which were primarily undertaken to save money. Regarding Section (1). Without any major alteration to the cylinder head pattern, we have by a number of minor modifications so improved the combustion chamber that we have successfully completed 50 hours endurance running under severe conditions at powers equal to the standard Bentley at high speeds, and up to 5% better at intermediate speeds. Admittedly sodium cooled exhaust valves were fitted but they are likely to cost less than the rocker and push rod which they replace on the conventional engine. Also with the improved valve guide cooling which will shortly be on test they may be unnecessary. Therefore it would be difficult to justify proceeding with the conventional engine as a result of the work done so far. It can only be justified by the fact that the 8-cyl. is required very urgently and the conventional is an insurance policy against unknown troubles. | ||