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).
Letter from Rolls-Royce of American, Inc. discussing the switch from Bethlehem to Champion A-63 spark plugs due to performance issues.
| Identifier | ExFiles\Box 35\3\ scan 137 | |
| Date | 7th March 1921 | |
| x 4196 OYS/G 7.3.21 March 7th. 1921. Mr. Claude Johnson, Managing Director, Rolls-Royce Ltd., London, England. Attention Messrs. Royce & Hives. Dear Sir, x 4277 x 4196 RE SPARK PLUGS. Replying to Mr. Hives' report Hs{Lord Ernest Hives - Chair}6/LG9.2.21, we wish to advise Mr. Hives that we have abandoned the use and further experiment with Bethlehem plugs because on the demonstration car 22-LW three or four porcelain cracked off about 3/8" from the tip after about 2000 miles running; also the earthed electrode shook loose in the shell. The new Champion A-63 which we are now using, has the porcelain brought to a rather sharp point - the porcelain, in fact, is more like the A.C. porcelain or the one on the Bethlehem plugs. The cup shaped porcelain is no longer used on the Champion plugs we buy. This now Champion porcelain can be hammered into the wooden bench with a brass hammer without cracking, and the end of the plug, both porcelain and steel, can be fused down by an ox-acetylene flame without cracking the porcelain. The plugs give excellent results in service. Yours truly, ROLLS-ROYCE OF AMERICAN, INC. per Mr. M.{Mr Moon / Mr Moore} Olley. MO/G.{Mr Griffiths - Chief Accountant / Mr Gnapp} R R OF AMER FORM NO 12 B 11-20-1M (E) CO. (E505) | ||