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).
Comparison test of standard platinum and experimental brass H.T. distributor points under different ventilation conditions.
| Identifier | WestWitteringFiles\H\November1921\ Scan8 | |
| Date | 9th November 1921 | |
| R.R. 235A (50 T) (S H.{Arthur M. Hanbury - Head Complaints} 986, 19-2-21) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 3088 EFC. AB. 30. COPY 9th Nov. 1921. X.800 - BRASS FOR H.T. DISTRIBUTOR POINTS. A comparison has been made between the operation of standard distributor sparking points working unventilated and brass points with more than the standard ventilation. Whilst testing iridio-platinum contact points (reported AB.22/9.9.21) the distributor was sealed against ventilation by filling up the ventilation holes in the cam housing and around the upper bearing of the spindle, with bees-wax, and by covering the holes in the lower bearing casomh with paper. The sparking points were the standard platinum. The distributor was run for 470 hours, at the end of which time, everything in the cam housing was smothered with iron oxide, and the cam roller was very badly worn. The copper piece on which the rotor platinum is mounted had corroded slightly, and the brass settings of the stationary points had darkened considerably; otherwise the performance was normal. A brass rotor and set of points was now arranged and run with all the normal ventilation, and also with the top of the distributor open, the centre carbon brush being held by a bridge-piece of ebonite. After 320 hours these points were pitted and blackened, the rotor sparking edge having burned away about .010". The stationary points were also pitted. | ||