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).
Report page detailing a series of spark plug tests, including flash over, dielectric strength, air pressure, and in-flight engine tests.
| Identifier | ExFiles\Box 58\2\ Scan150 | |
| Date | 1st September 1934 guessed | |
| Report No.R.A.E./E.{Mr Elliott - Chief Engineer} and I-865. -5- 10. Internal surface flash over test. Three plugs were subjected to this test. Each plug withstood 12000 volts for 10 seconds without internal flash over as required. Result satisfactory. 11. Dielectric strength test. Three plugs were tested for dielectric strength in accordance with the specification. Each plug withstood for 10 seconds a peak voltage of 15000 volts as required. Result satisfactory. 12. Sparking under air pressure test. Three plugs were subjected to this test. The electrode gaps were between 0.012 inch and 0.015 inch. Each plug sparked regularly under an air pressure of 100 lb. per sq. inch. Result satisfactory. 13. Engine tests in flight. Nine of the plugs were fitted in a Jupiter VII.F. engine in Bulldog aircraft J.9580, one plug in each cylinder. Previous to fitting, the electrode gaps were recorded and the plugs were tested for sparking under an air pressure of 100 lb. per sq. inch, which test was completed satisfactorily. The engine details were as follows:- Compression ratio. 5.5:1 Maximum R.P.M. 1950 Normal R.P.M. 1775 Average B.H.P. 405 Fuel. D.T.D. Specification No.134. | ||