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 of various sparking plugs for a supercharged engine.
| Identifier | ExFiles\Box 162\6\ img110 | |
| Date | 27th May 1927 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/VH. c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to BY.{R.W. Bailey - Chief Engineer} 44425 Hs{Lord Ernest Hives - Chair}/VH1/LG27.5.27. X1998 X4550 F.10. WITH SUPERCHARGER. Sparking plugs. So far the chief trouble experienced with F.10. under supercharged conditions has been that of finding a suitable sparking plug. (a) The oil conditions during light running after giving the rear blower bearing a charge of oil. (B) Increased heat flow through the engine during conditions of maximum boost. Lodge RB{R. Bowen}-4 and KLG. 356 were first fitted. Of these the Lodge BR-4 plugs stood up better than the KLG.356 but both shewed a tendency to oil up. Under full throttle conditions the BR4 plugs gave the more satisfactory results. After 10 hrs. total running very few of the Lodge BR4. plugs remained intact while the KLG. 356 plugs lasted only half the time. We are now using Champion R.12. plugs (Seliminite insulators and detachable centres) which up to the present - after 15 hrs. total running - are giving satisfactory results. Champion R.1. plugs were slightly more liable to oil up than the Champion R-12 but we think that under improved conditions (modified supercharger, rear bearing lubrication etc.) they would prove satisfactory. We think that if the R.1. plugs were made the same length in the body as the R.12. long type, they would be more accessible and withstand heat conditions somewhat better. Lodge BR4. KLG.356. Champion R.12. Non-deatchable Non-detachable Detachable centres. centre. centres. 'Seliminite' insulat- Mica insulator. Mica insulator. or (porcelain) Oils up readily. Oils up readily. Fires under oily conditions. Hs{Lord Ernest Hives - Chair}/V.Halliwell. | ||