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).
Letter to the Royal Aircraft Establishment regarding coil ignition specifications, gear ratios, and component delivery.
| Identifier | ExFiles\Box 168\1\ img286 | |
| Date | 25th March 1937 | |
| 25th March 1937. Lr{Mr Ellor}/Wst.3/AP. The Chief Superintendent, Royal Aircraft Establishment, South Farnborough, HANTS Dear Sirs, RE: COIL IGNITION. We beg to reply to your letter of the 20th inst., reference E.{Mr Elliott - Chief Engineer} & I/M.G.752, and would say that we are sending to you today under separate cover the skew gears for driving the units in question. With regard to paragraph 3 of your letter, the direction of rotation is - A.side anti-clock-wise looking on the top of the distributor and B. side clock-wise. The gear ratio between the engine and the ignition generator on this particular Kestrel engine was 2.207 - 1, but we would point out that this ratio varies according to the type of engine to which the generator is fitted i.e. we aim at gearing the generator to the engine so that it will give at 1000 engine R.P.M. approximately 13 volts. We are also sending you herewith one print each of drawings D.7255 and D.7256 showing the mounting of these distributors. Replying to your last paragraph, we estimate it would be one month before we have a complete screened distributor to test as we have abandoned the original screens produced, and are awaiting the manufacture of re-designed screens in the form of castings. In order to get screening tests carried out as quickly as possible on these distributors we suggest you arrange some form of sheetmetal screen yourselves at the R.A.E. Yours faithfully, FOR ROLLS-ROYCE LTD. | ||