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).
Performance comparison of Lodge and A.C. Sphinx spark plugs under test conditions.
| Identifier | ExFiles\Box 79\2\ scan0177 | |
| Date | 2nd February 1925 | |
| To Roy.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL. X1026 Hs{Lord Ernest Hives - Chair}/ACL/LG18. 2. 25. RE. LODGE AND A.C. SPHINX PLUGS. X4425 Lodge 183/130 Sphinx 18 CPT. Both plugs withstand oil very well, having run perfectly in test engine for 9 hours under excessive oiling conditions. They both pre-ignite when running under full load at high speeds, in a short time. The Lodge is slightly the better of the two in this respect. The porcelain fractured on two of the Lodge plugs but this may have been caused by the plug spanner. Hs{Lord Ernest Hives - Chair}/ACL. | ||