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).
Test report detailing conclusions on fuel nozzles, cylinder performance, and general engine conditions.
| Identifier | ExFiles\Box 133\3\ scan0062 | |
| Date | 6th March 1939 | |
| -2- Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards}4/MH.{M. Huckerby}6.3.39. General Conclusions - Cont'd.{John DeLooze - Company Secretary} (3) A relatively low differential ratio is required on an R.A.F. fuel nozzle to give snappy operation, but considerably higher values are permissible with the integral construction Bosch injector. (4) "Inverted" nozzles, i.e. with valve opening outwards, suffer from the disadvantage of causing a large fuel line capacity. (5) Rotational air swirl did not improve the performance, and was very sensitive to the dimensions of the masks, slight errors upsetting the suitability of the nozzles, and lowering the MEP. (6) A second cylinder was down for power due to a reduction in induction port turbulence following on the use of larger ports and valves, higher motoring losses and overheated nozzles. Detailed Report. The original cylinder is as stated in the first summary, but particulars of the other are as given below. The block contains two liners, one being a dummy, the object being to reproduce the conditions of the end cylinder of a block of six. Compression Ratio........... 13.5 and 14.0 Exhaust valve lift.......... .600" and .475". Total area past inlet valves.. 5.624 sq.ins. (small valves) 6.259 sq.ins. (large valves high lift) 6.108 sq.ins. (large valves low lift) General Conditions of Test. As for previous report, except that valve timing is I.O 7°L; I.C. 23°L; E.O. 30°E; E.C. 10°L. | ||