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).
EAC engine with opposed sparking plugs and induction pipe in the cylinder head.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan289 | |
| Date | 12th June 1925 | |
| R.R. 498A (50 H) (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}/ACL/C.G.9.25. C EAC. ENGINE WITH OPPOSED SPARKING PLUGS AND INDUCTION PIPE IN CYLINDER HEAD. (Cat.1875). The following tests have been taken to compare the induction system of this engine with that of the standard EAC. The power output was found to be less over the whole range than the average power obtained for the standard engine. The compression ratio was approximately the same being 4.2 to 1 against 4.15 to 1 for the standard model. In order to determine if the higher temperature of the induction pipe - which on this engine is part of the cyl. head casting and partly water jacketed - would account for the loss in power compared with the standard engine; we took power curves with the jacket water at 80°C and again at an average of 35°C. The hot spot was in operation during both these tests. The appended curves (Sheet 1.) show the power loss due to the temperature of the induction pipe, and the higher curve - with the water temp. at 35°C - is approximately the same as an average power curve for the standard engine. A curve is also given and the power is shown with the water temperature 80°C - hot spot disconnected. The difference between these two lower curves is the power we lose due to the hot spot when used in conjunction with the jacketed pipe. From these curves we see that assisting the distribution by means of the hot spot alone is more efficient contd :- | ||