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 the performance of spark plugs, types X405 and X406, run in an 'Exe' single-cylinder unit.
| Identifier | ExFiles\Box 163\5\ img026 | |
| Date | 29th May 1936 guessed | |
| -2- approx. 50 hours with no trouble at all and no signs of over heating. Electrode erosion was very small only .007" and although these plugs were of the detachable type very little gas leakage had occured. That which had occured was not detrimental to the running of the plugs. (2) Plugs type X405 and X406. These were run on the "Exe" single cylinder air cooled unit for 35 hours at M.E.P.'s between 150 and 190 cylinder head temperature being 282°C. The condition of the plugs at the conclusion of the run were remarkable there being no appreciable lead attack and no signs of distress at all in the plug. We have arranged with the A.C. Co., for them to make up for us more of these plugs of the Sinterkorund pattern screened suitable for engine running and hope to continue our tests with these. Yours faithfully, FOR ROLLS-ROYCE LTD. | ||