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).
Performance graph plotting piston displacement against crank angles at various RPMs.
| Identifier | WestWitteringFiles\K\September1923\ Scan58 | |
| Date | 17th August 1922 | |
| RR 495A (LH{Mr Haworth}) (SL11D 17-8-22) MP 275518B G.IV Spring Used—Rating 6.2 Diagram Area Engine Cyl. No. AVERAGE Air. Temp. Bar Temp. Cooling Water Temp. R.P.M. Lbs. Lift H.P. I.M.E.P. B.M.E.P. Max. Expl. Pr.{Percy H. Rose} Av. Expl. Pr.{Percy H. Rose} Mechanical Efficiency Indicated Vol. Efficiency 1" = 6.2 lbs/p" ATMOS. PR.{Percy H. Rose} LINE 2000 RPM 1250 RPM 2400 RPM PISTON DISPLACEMENT FOR CRANK ANGLES | ||