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).
Comparing the performance of engine models X-F-12, X-F-14, and X-F-18.
| Identifier | ExFiles\Box 36\2\ scan 105 | |
| Date | 14th March 1927 | |
| R.R. 405 (40 H) (RL 42 15-7-25) J.H., D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT. 14.3.27 COPIES TO: R.CJ. BJ. WOR.{Arthur Wormald - General Works Manager} By.{R.W. Bailey - Chief Engineer} E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} EP.{G. Eric Platford - Chief Quality Engineer} PN.{Mr Northey} OY. Expl. No. REF. Hs{Lord Ernest Hives - Chair}/VHl/LG15.3.27 OBJECT OF TEST. COMPARISON TEST ON X-F-12 WITH HP. FIGURES OBTAINED ON X-F-14 & X-F-18. TESTER. V.Halliwell. CONDITIONS. X-F-12 - carburettors off X-F-18. Pistons - originally E.28480 with skirt of decreased length and unstrengthened piston rings. Valves - unstrengthened tulip type E.27944. SUMMARY OF TEST. As regards power output we have found that X-F-14 and X-F-18 are substantially the same, and the attached curve for X-F-14 was taken when the latter was fitted with unstrengthened tulip valves E.27944 as above. The pistons were high compression type E.29831 fitted with piston rings E.29207/8 which gave a 50% increased tangential loading. When running X-F-12 it was observed that the piston rings were not holding the pressure as they should have done - this being evident by the way the breather was blowing. Overoiling was experienced when taking the power curve. It is probable that some loss of power accompanied these symptoms and that the curves B. and C. on the attc. sheet have suffered accordingly. The curves C. shews the effect of contd :- | ||