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).
Test results detailing the temperature curves for various ignition coils under different fitting conditions.
| Identifier | ExFiles\Box 164\5\ img397 | |
| Date | 26th August 1938 | |
| DETAILS OF TEMPERATURE CURVES. (1) No.19A Delco-Remy coil fitted to std. bracket, heat resisting washers not used. Maximum temperature of crankcase 79°C. (2) As curve (1) but using the heat resisting washers to heat insulate the coil from the crankcase. (3) No.2.A. Delco-Remy coil fitted to standard bracket, heat insulating washers not used. Maximum bracket temperature 79°C. This test tends to prove that the first lot of coils obtained are cooler running than the later supplies. (4) No.19.A. Delco-Remy coil fitted to standard bracket without insulating washers, and with the bracket mounted on the frame. Maximum temperature of bracket 48°C. This test shows how a saving of approx. 20°C. may be obtained by fitting the coil bracket to the frame. (5) Lucas Sports coil S.1. fitted on std. Delco-Remy type bracket, without heat insulating washers. Bracket temperature 79°C. (6) Same as (5) but with heat insulating washers bracket temperature 79°C. max. This test combined with (1) and (2) proves the heat insulating of the coil from the crankcase is detrimental with respect to temperature. (7) R.R.E.N.3. coil made on similar lines to the Delco-Remy with a metal case, mounted on standard bracket without heat insulating washers. Bracket temperature 83°C. (8) R.R. Wraith 20,000 turn coil to D.76573. No.N.18 mounted on platform, glowray ballast 2.45 ohms resistance. Bracket temperature 78°C. (9) R.R. Std. P.III coil to D.75260 on R.R. type bracket. Nickel ballast. Maximum temperature of bracket 78°C. (10) Same as (9) but using Glowray ballast of 2.45 ohms resistance. Max. bracket temperature 75°C. (11) Runbaken glass cased oil immersed coil, type S.22. Fitted | ||