Test report on Block Sparking Plugs type 12/20, noting pre-ignition issues and power loss.
| Identifier | ExFiles\Box 33\3\ Scan231 | |
| Date | 23th November 1922 | |
| Mr. Hives from GWH. {George W. Hancock - Head Chateauroux} X1812l. 23.11.22. BLOCK SPARKING PLUGS - type 12/20. These plugs have been tested on the test bed engine and have run 10 hours. We had to change a valve due to pre-ignition from one of these plugs. They all pre-ignite more or less - power also being down with these plugs. GWH. {George W. Hancock - Head Chateauroux} | ||
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).