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 conducted on Champion sparking plugs, types AE.4, AE.9, and AE.1.
| Identifier | ExFiles\Box 35\3\ scan 201 | |
| Date | 23th March 1928 | |
| 23.3.28. REPORT ON CHAMPION SPARKING PLUGS TYPES : AE.4., AE.9., AE.1. TYPE AE.4. These plugs were tried in a 7/1 compression 'F' engine running on 20/80 Benzol/Aviation, Lodge A-30 and KLG.541 plugs being fitted side by side with the Champion. The throttle position was adjusted to give rated power (480 HP.) at 2250 r.p.m. and a power curve was taken, the engine speed being reduced by the brake to cover conditions corresponding to reduced propeller speed at ground level, with the throttle up to the gate. Pre-ignition set in at 2100 r.p.m. in the case of several of the Champion plugs only and the test was discontinued. The B.M.E.P. at this point is approximately 136 lbs/sq.in. With Lodge A-30 or KLG.541 plugs fitted, the engine speed may be reduced to 1700 r.p.m. without pre-ignition setting in, although detonations are severe. Approximate time on each speed 2 / 3 minutes. TYPE AE.9. A set of these plugs were fitted to the flight test engine (8/1 comp: ratio) and were found to pre-ignite very badly on 10 cc's gal/TEL/Aviation. They do not, therefore compare very favourably with the R.12 type of Champion plugs which are fairly satisfactory under flying conditions. TYPE AE.1. Tests carried out with these plugs on the super-charged F.ll indicate that they run somewhat hotter (more prone to pre-ignite) than the Champion R.ll. Some Lodge A-30 plugs were run concurrently with the Champion A.E.1. plugs and the tests shewed that there was very little to choose between the behaviour of the two types. This suggests that Lodge A-30 and Champion AE.1 plugs will stand approximately the same amount of heat. Their lasting qualities have yet to be proved and we propose to give these plugs further tests on 7/1 compression engines. ---------------- Expl: Dept: | ||