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 7,100-mile performance and consumption tests of the Wraith III No. 1 Unit engine in France.
| Identifier | ExFiles\Box 108\1\ scan0189 | |
| Date | 10th September 1937 | |
| To Sg.{Arthur F. Sidgreaves - MD} from Rm{William Robotham - Chief Engineer}/IKW. c. ES. c. DY.{F R Danby} c. De. c. RM.{William Robotham - Chief Engineer} c. Ex. c. RPS. c. O.H. File 600a Rm{William Robotham - Chief Engineer}/INE.3/MR.10.9.37. Revised report as circulated. Tests in France - 26-C-VI. 25/30. Report on 7,100 miles running - Specification HPS{Horace Percy Smith - Experimental Factory Mgr}/CE/19 and 24/6/37 and 2.3.9.18.22.26/7/37. Engine Wraith III. No. 1. Unit. Performance was good and up to present 25/30 standard. The maximum timed speed over a kilometer was 78.m.p.h. An unsatisfactory front and rear engine mounting prevented a true standard for noise and periods being given, but the engine was neither quiet nor smooth. It is claimed that a better engine in these respects has been obtained at works by reverting to the long studs from the crankcase through the cylinder block to the head, and further improvement effected by isolating the rear of the gear box from the cruciform member. The maximum oil temperature reached with sustained speed was 126°C during which the oil pressure remained at 25lbs/sq." Duckham's H.P.) was used. The consumption was as follows:- On 1st. gallon - 721 miles. 2nd. 1202 3rd. 988 4th. 1183 5th. 995 6th. 980 Average consumption 1011 m.p.g. which is nearly twice as heavy as the Phantom III running in France at the same time. The average petrol consumption was 11 m.p.g. | ||