Specifications for various engine units including U-7-S, W.7.2, and Wraith II.
| Identifier | ExFiles\Box 155\2\ scan0116 | |
| Date | 13th July 1937 | |
| -3- U-7-S. continued. Ex.19457 inlet valves, 1.45 dia. E.60260 exhaust valves 1.20 dia. Induction system similar to standard but with flanges reversed to suit head. Up-to-date drain scheme without vent. Standard R.R. flywheel and clutch with chromium plated driven plate. Zinc interwoven facings. W.7.2. (Spare Unit) 20/25. crankcase modified to suit large bore, non-spread centres. whitemetal main bearings. 20/25. crankshaft and balance weights, LOP.E.60245. modified to suit Borg & Beck clutch. Latest type drilled up rods LOP.EB.1806, with whitemetal big ends. Aerolite pistons L.4. Standard 20/25. cyl. head (non turbulent) and valves. .075" liner under cyl. block, bringing C/R. to 6:1. Stromberg downdraught carburetter and Ex.18316 inlet manifold (1st. stage sloping base hot-spot) 11" type ventilated clutch, Borg & Beck. Wraith II. No.1. Unit (Spare Unit) Unit as designed. W/M. main bearings and steel shims. Hall's metal big ends. Up-to-date bushing of oil pump. Sludge trap, improved suction strainer and ribbed lower half. External oil pressure filter. 10" B. & B. clutch. Wraith No.II. No.2. Unit (25.G.V1) As No.1. unit but with- W/M. main bearings with RR.56. solid shims. Hall's metal big ends with RR.56 shims. Swedish wire valve springs - 1 - 6 Rm. {William Robotham - Chief Engineer} 260 made by tempered spring Co. 7 -12 EB.3256 coiled by R.R. 2 inlet cam camshaft ex C.15 unit Ex.24268. continued | ||
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).