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).
Engine power output for a 10,000-mile car following modifications to the camshaft, pistons, and various exhaust systems.
| Identifier | Morton\M13.2\ img123 | |
| Date | 27th October 1931 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} c. Wor.{Arthur Wormald - General Works Manager} Da.{Bernard Day - Chassis Design} c. E.{Mr Elliott - Chief Engineer} BV. ORIGINAL Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}1/AD27.10.31. X5771. X5730. POWER OUTPUT - 10.000 MILE CAR. We have now had the engine on the test bed which has been prepared for the next 10,000 mile test and is fitted with the new camshaft and higher compression pistons. Curve Rm.{William Robotham - Chief Engineer}48 shows the power output of this unit compared with the original unit which was fitted with 112° shaft and high lift rockers and which succeeded in doing 76 over the half-mile on Brooklands with cut-out open. Curve Rm.{William Robotham - Chief Engineer}49 shows the effect of :- (1) Open exhaust. (2) The complete P.2. short type exhaust system. (3) The W.W. exhaust system to N.sch.3285/6/7. The only alteration made to this last scheme was that the 1½" pipe was retained but the area of the fishtail outlet was increased to the same as that on the P.2. We are now fitting the car up with the P.2. expansion box as per the W.W. scheme, but believe we may have to go to 1¾" pipe for the fishtail in order not to spoil the effect of the large expansion chamber. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||