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).
Tests on different types of sparking plugs due to misfiring issues, concluding K.L.G. plugs are unreliable.
| Identifier | ExFiles\Box 34\3\ Scan006 | |
| Date | 23th October 1919 | |
| To Bn{W.O. Bentley / Mr Barrington}, from Hm.{Capt. W. Hallam - Head Repairs} c, to Hs.{Lord Ernest Hives - Chair} X.2635 COPY. X.1918 X.2641 Hm{Capt. W. Hallam - Head Repairs}5/W23.10.19. With reference to Mr. Royce's memo, ref:- R4/G20.10.19, on testing repair cars, we are experiencing a somewhat similar trouble to that described in R's memo, and I have been carrying out some tests myself on car No.64.EB. This car is fitted up with the old type trembler coil. The misfiring at slow speed has been traced to sparking plug troubles. It is common to both ignitions, that is, when K.L.G. plugs are used. We carried out compression pressure tests on sparking plugs, after having been used in a car for about 20 miles. These plugs were tested without being cleaned. Attached are particulars of the difference between 12 Bosch Plugs, 12 K.L.G. Plugs, and 6 H.S.C. Plugs. The H.S.C. Plugs were supplied to me by Mr. Hives for a trial. The Bosch Plugs were four point plugs, which had been used for many years, and the K.L.G. plugs were new ones which were taken out of stock. We are of the opinion in the Repair Dept: that K.L.G. Plugs are very wasteful, and unreliable. We can only get a good set of plugs by selection, and as shown in the figures out of the 12 new plugs Nos. 4,5,10,11 and 12 at least, could not be expected to function properly. Could the Experimental Dept. go into the question of choosing a more reliable sparking plug please ? Hm.{Capt. W. Hallam - Head Repairs} | ||