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).
Visit to H.R. Ricardo & Co. Ltd. to discuss the correlation of single-cylinder engine results with main engines.
| Identifier | ExFiles\Box 134\1\ scan0006 | |
| Date | 12th July 1937 | |
| By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards} c. Da.{Bernard Day - Chassis Design} Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards}7/R.12.7.37. VISIT TO H.R. RICARDO & CO. LTD., SHOREHAM. The above Works was visited by the Writer with the primary object of obtaining information regarding the correlation of single cylinder results with main engines. Mr. H.R. Ricardo, Mr. Alcock in charge of the Aero Section and Mr. Holt in charge of the Diesel work were interviewed. Other information was obtained on the subject of valve size and timing with regard to exhaust power loss, and also some information on the subject of venturi valve seats. These three items are dealt with below:- (1) Correlation of S/C and Main Engines. Great faith in single cylinder work was expressed by Mr. Alcock, who gave us the following method of lining up results. Compression pressures were taken on the bare cylinder, i.e., without any induction or exhaust pipes, and then taken on the cylinder complete with carburetter system, noting at the same time the depression in the induction pipe. Two methods of procedure were now put forward. (i) The difference between the compression pressures, making allowance for the drop in pressure at the inlet valve as measured by the induction depression, was taken as being the same percentage difference as would exist between thepower curves. A correction factor was thus found for each speed, which was applied to the measured power curves, and a "basic" power curve thus obtained which, it was stated, was a true measure of the capabilities of that particular cylinder and head. (2) A second method was to throttle the engine while motoring over with the induction system fitted to give a compression pressure equal to that obtained with the bare cylinder, and the depression was then noted. Subsequent power curves were then run with these depressions, and these power readings were taken as basic figures. | ||