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).
Trials car, detailing engine horsepower, specifications, and modifications.
| Identifier | WestWitteringFiles\L\Jan1924-March1924\ Scan114 | |
| Date | 1st February 1924 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT. Expl. No. 9887 X8770-9771 REF: Hs{Lord Ernest Hives - Chair}1/LCL.2.24. S E C R E T. THE SECOND PH'S TRIALS' CAR - 46-PK. (40/50 WITH EAC ENGINE) To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. RG.{Mr Rowledge} c. to PH. BA. c. to E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} ✓ c. to Wsy. EP.{G. Eric Platford - Chief Quality Engineer} ✓ This car was sent to London this morning. The engine gave the following HP: on the test bench :- Reg. No. CH 3918 R.P.M. HP. 625 36.5 750 42.7 1000 55.5 1250 68.25 1500 80.5 1750 92.0 2000 100.8 2250 106.0 2500 109.5 Compression ratio 4.6 to 1 Max. comp: by gauge 89 lbs. The parts fitted to this car are as follows :- The engine was fitted with a Camshaft with the cams at 114°. We cannot appreciate any difference between 114° and 110° but both these Camshafts are better than the 118°. We anticipate trying a lower lift Camshaft before the final decision is made. We fitted the screw adjustment for the rockers. This arrgt. works very well indeed and overcomes all the troubles. The cyl. head was fitted with monel metal tubes where the studs pass through. The makers of the monel metal tubes had considerable difficulty in drawing the special tubes for the head. The shape was therefore altered so as to reduce the work on them. This meant leaving out the taper wedges. We find that the monel metal makes quite a tight joint without the wedges. The original engine which we have run for 500 hrs. was built up this way. The tappet rods are the tubular type with the hardened ends. Oil is supplied to all seven bearings on the Crankshaft. contd:- | ||