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).
The conditions existing in a G.11 cylinder under firing conditions.
| Identifier | WestWitteringFiles\K\September1923\ Scan66 | |
| Date | 21th September 1923 | |
| R.R. 493 (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} ORIGINAL. EXPERIMENTAL REPORT. COPIES TO: R.C. WOR.{Arthur Wormald - General Works Manager} By.{R.W. Bailey - Chief Engineer} E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} OY Expl. No. X.4225 X.4580 REF. He5/LG21.9.23. OBJECT OF TEST. To determine the conditions existing in the G.11. cylinder under firing conditions by means of the R.A.E. Electrical indicator. TESTER. W. A.{Mr Adams} Robotham. CONDITIONS. G.11. engine run on the Bench, the power being absorbed by a Froude Water Brake in the usual manner. Atmospheric conditions as specified. Mixture used - Aviation with 15% Benzol. Controls set for maximum power. Standard exhaust system. SUMMARY OF TEST. The diagrams are the average of cards taken from all six cylinders. In no case was the maximum variation between cylinders very great. The timing is the average of the 6 cylinders and each cylinder was marked on the pressure time card at the time of the test. The explosion diagram shews a high I.M.E.P. in comparison with the B.M.E.P. measured - the result being a distinctly low mechanical efficiency. We have since taken cards at various engine speeds, however, and find the mechanical efficiency as obtained from the indicator is low throughout the whole range. The maximum explosion pressure given is the highest pressure recorded at the peak of the figure, the average explosion pressure is the mean pressure recorded at the same point on the cycle. The variation between these two is of course, contd:- | ||