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 from Rudge-Whitworth discussing valve timing and cam acceleration figures.
| Identifier | ExFiles\Box 85\3\ scan0020 | |
| Date | 17th May 1934 | |
| X.207 SUCCESSORS TO GRY.{Shadwell Grylls} Please let me have comparison with the R engine shaft we are making Coventry. Rudge-Whitworth Limited TELEGRAMS, RUDGE, COVENTRY. TELEPHONE 4001. EDWARD DE STEIN, CHAIRMAN. SIR HERBERT E.{Mr Elliott - Chief Engineer} BLAIN, C.B.E. DEPUTY CHAIRMAN. FRANK G.{Mr Griffiths - Chief Accountant / Mr Gnapp} WOOLLARD, MANAGING DIRECTOR. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} H.{Arthur M. Hanbury - Head Complaints} ASHTON RESEARCH LABORATORY GLH/DMP 17th May, 1934 RM{William Robotham - Chief Engineer} KR Messrs. Rolls-Royce Ltd., DERBY. For the attention of E.{Mr Elliott - Chief Engineer} W. Hives, Esq. Dear Sirs, Further to the visit of Mr. Hives and Mr. Ellor yesterday, we hope the following information on valve timing is what you require. With .01" tappet clearance our standard valve timing is:- Inlet opens 19° before top and closes 55° after bottom Exhaust opens 54° before bottom and closes 31° after top. Acceleration is of the order of 2000 ft/sec² for the first 20° and rises to a maximum of 8600 ft/sec² with an engine speed of 5000 r.p.m. The racing cam on which we gave you our timings yesterday has an acceleration of 12000- 14000ft/sec² for the first 6° and 8000 ft/sec² from 6 - 15° at an engine speed of 5000 r.p.m. The acceleration figures are with respect to cam revolution. At your convenience we should be interested to have further information on oil cushioning of the valve operation. Contd...... | ||