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).
Indicator work for E.A.C.11 engines, detailing carburettor and exhaust system tests.
| Identifier | WestWitteringFiles\L\2Jan1924-March1924\ Scan89 | |
| Date | 28th March 1924 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H. D.{John DeLooze - Company Secretary} Expl. No. REF: Hc/ACL28.3.24. EXPERIMENTAL REPORT. INDICATOR WORK ON E.A.C.11. ENGINES. The attached curves represent the maximum output of this engine, as the carburetter and exhaust systems employed were selected to give the minimum of restriction. The carburetter was a R.R.C.H. (Eagle V111 type) used in conjunction with the standard induction system, but with 'hot-spot' disconnected. The exhaust system used was found by experiment to give the best power output. It consisted of a separate straight pipe to each exhaust port, 4' 6" long and 1.875 dia. From the exhaust and induction diagrams it is seen that the exhaust falls considerably below atmospheric and records very little back pressure at end of stroke. The drooping of the curves at 1000 r.p.m. is due to the bad distribution with the carburetter used. It was found necessary to supply heat to the charge below 1500 r.p.m. Volumetric efficiency. The curve given is the indicated vol. effcy. and is not reduced to N.T.P. Experiments on Exhaust Manifolds. Tests were taken to find the losses due to exhaust manifolds. Four types were tried - viz :- (1) Standard. (2) Separate exhaust pipe to each port. (3) Two separate manifolds - one to each three cylinders. (4) One large diam. manifold - 3.75" dia. at outlet end. contd:- | ||