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).
Programme of test bed work for the Wraith III No.6 Unit, detailing new features and test procedures.
| Identifier | ExFiles\Box 155\2\ scan0157 | |
| Date | 30th September 1937 | |
| File 1315 R... From Rm {William Robotham - Chief Engineer} /Swdl. {Len H. Swindell} Rm {William Robotham - Chief Engineer} /Mths. {Reg Matthews} Rm {William Robotham - Chief Engineer} /CTS. {C. Trot Salt - Carburation} Rm {William Robotham - Chief Engineer} /Id. Rm {William Robotham - Chief Engineer} /Swdl. {Len H. Swindell} 12/MH. {M. Huckerby} 30.9.37. PROGRAMME OF TEST BED WORK. Further to our memo Rm {William Robotham - Chief Engineer} /Swdl. {Len H. Swindell} 2/AP.15.9.37. No. 30 Bed. Wraith III. No.6 Unit. New unit incorporating following special features - (1) Up to date solid liner cylinder block. (2) Hykro crankshaft with A3.6 main and big end bearings. (3) Oil retainer device to Rm. {William Robotham - Chief Engineer} 455 with oil groove in rear main bearing increased from .172 to .250. (4) Increased helix angle gears ( 41° ) (5) Front 6 tappet bushes in RR.50 crankcase material, rear 6 in A {Mr Adams} /P. ----- Unit to have normal running in with P.4 and hard oil mixture following which test as follows - (1) Power curve open exhaust and with Wraith III silencer if available. (2) Warwick to fit eccentric rocker pedestal studs with Bentley rockers. EB.3256 springs and E.88709 top washers to be fitted. In this condition repeat open exhaust and silencer curves. (3) Check for valve bounce up to 4500 R.P.M., also spring surge over speed range. (4) Check for tappet noise periods and what is the maximum clearance for quiet valve operation. (5) Run 1 hr. oil consumption and note whether oil retaining device is effective. (6) Co-operate with Rm {William Robotham - Chief Engineer} /FJH {Fred J. Hardy - Chief Dev. Engineer} regarding the timing gears. | ||