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).
Test report on E.27 sparking plugs used in a 4¼ Litre Bentley engine.
| Identifier | ExFiles\Box 142\3\ scan0184 | |
| Date | 20th April 1937 | |
| 1204 Files. No.30.Test House. 20.4.37 SPARKING PLUGS. The following plugs have been tested under the conditions stated. ------ Type E.27. Engine 4¼ Litre Bentley (as Production) Test Full throttle. Full load = 10 hours. } 30 mins. at 4000 Part " ¼ load. = 10 hours. } 25 " " 4250 } 5 " " 4500 (every hour) Petrol: Esso Ethyl Conclusion The plugs gave no trouble whatever during the test. We have tested several types of 'China' plug recently, and they all have the same characteristic. There is a very noticeable improvement at low speeds re missing and erratic running, associated with the usual micro insulated plug. C.T.Salt. | ||