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).
The performance of a new petrol pump bracket, exhaust pipe stay, and a 'Deterbulated' cylinder head.
| Identifier | ExFiles\Box 101\2\ scan0026 | |
| Date | 7th July 1936 | |
| x500n 14° Correct HOTEL DE FRANCE. CHATEAUROUX. Indre. France. GWH{George W. Hancock - Head Chateauroux}/IMW{Ivan M. Waller - Head of Chateauroux}/2/JAB. 7th July 1936 To. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c to. G.W.H. 22. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} V.{VIENNA} New Petrol Pump Bracket. We have fitted the rubber mounted petrol pump bracket. This has had no silencing effect whatsoever, the noise of the pumps being transmitted along the petrol pipes. With the pipes disconnected, there is not sufficient rigidity to support the pumps properly, their movement being restrained entirely by the petrol pipes. Exhaust Pipe Stay. As reported in our memo GWH{George W. Hancock - Head Chateauroux}/IMW{Ivan M. Waller - Head of Chateauroux}/2/JAB.28.6.36. the new stay is 0.28" shorter than the old one. It was necessary to strain the exhaust pipe to fit it with the result that the lug broke off the pipe. We have therefore, fitted up the new exhaust pipe with the old stay. Deterbulated Cylinder Head. This has now run 1,500 miles. We were first troubled by misfiring on the pick-up using the A.C. plugs set at .030". There was no external sparking, but the trouble was overcome by fitting the KLG 850 plugs set at .020". Pick-up is smoother with the new head & tick over is more regular, but the compressions are not at all even on all cylinders, and it will be necessary to investigate this before a final criticism of the improvement can be given. We are using the modified ignition governor used latterly with the other head. It has been necessary to re-time it from 14° early to 18° early, these being the minimum settings without loss of power. We are now getting bad detonation at 10 MPH. and light detonation at 15 MPH. disappearing between 20 & 25 MPH. This can be eliminated by retarding the hand ignition control 5 notches at 15 MPH. and 10 notches at 10 MPH. but unless it is quickly advanced as speed gathers, a loss of power is experienced. There may be a slight loss in ultimate maximum speed, but the general performance is quite as good as with the former head, and the engine seems smoother. We intend, after G.W.H. has inspected the other head and valves, to clean them up and replace them so as to obtain a further standard of comparison between the two. ----------------- GWH{George W. Hancock - Head Chateauroux}/IMW.{Ivan M. Waller - Head of Chateauroux} John. Walker. | ||