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).
Testing procedures and specifications for the W.III No.4 and Wraith Ripple No.2 engine units.
| Identifier | ExFiles\Box 155\2\ scan0333 | |
| Date | 30th June 1939 | |
| -3- W.III NO.4 UNIT. Continue endurance of Vandervell big end bearings in accordance with previous memo. WRAITH RIPPLE NO.2 UNIT. Unit as removed from 12.B.V. fitted with following special features which after test, to be re-installed in same chassis for 30,000 miles test. (1) 3-layer main bearings. (2) Crank with simplified oil drilling and longer rear end thread EB.4410. (3) .360 raised crown pistons 6.5 : 1 C.R. (4) Long dry linered cylinder block with coolant jet scheme. (5) Monichrome camshaft, but Wraith cam forms. (6) Simplified lower half filter. (7) Strengthened exhaust valves EB.4845. After running in, tests should include - (a) Power curve open exhaust. (b) Power and detonation curve with standard exhaust system on Redline fuel. Governor curve to be made to suit required advance line. (c) With standard exhaust system check valve bounce (d) At 30/35 lbs/sq.in. oil pressure, 100°C inlet temperature, take oil consumption for 1 hour at 4000 r.p.m. on Motorine C. Record blow-by and repeat if in excess of 2 pts/hr. (e) Gears to be quiet in respect of rattle and whine both light and under load. (f) Unit generally to be tuned up, all leaks cured and idling set, noting that no over-oiling on opening up after idling. | ||