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).
Performance improvements and testing plans for a new Ramp No. 2 cylinder head design.
| Identifier | ExFiles\Box 133\2\ scan0102 | |
| Date | 19th November 1934 | |
| To - Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Wd.{Mr Wood/Mr Whitehead} c. to Wor.{Arthur Wormald - General Works Manager} c. to E, c. to Rg.{Mr Rowledge} c. to By.{R.W. Bailey - Chief Engineer} [Signature] C.L.S. re Hs{Lord Ernest Hives - Chair}/Smth.14/KW.13.11.34. With reference to the comments in the above memo on the report of Ramp No.2 Head (Hs{Lord Ernest Hives - Chair}/Wd{Mr Wood/Mr Whitehead}/CHP.1/GB. 1.1134) it is suggested that if one accepts the criterion that detonation becomes offensive at audibilities greater than 10 ft. then the improvement of the Ramp No.2 over the standard is substantial particularly in view of its 8 lbs/sq.inch greater m.e.p. The inlet passage of the close centres standard head is in process of being machined to the same dimensions as Ramp No.2 and a direct comparison between the two heads with similar breathing organs will be made. It is proposed to carry out air blowing tests on the effect of the influence of design on the orifice coefficient as you suggest but this work will be done prior to running tests. The timing responsible for the maximum peak power curve of the Ramp is given on page 6 of the report (No.2 timing) and is I.O. 14°E.{Mr Elliott - Chief Engineer}, I.C. 36°L., Ex.O. 52°E.{Mr Elliott - Chief Engineer}, Ex.C. 8°L. There is no response on the standard head to this timing. The research into the valve timing variations has been continuous for the last three months. Thus, with reference to the quoted example of the E.R.A. supercharged engine, overlaps up to 35° on the standard head have been tried and have produced no appreciable increase in m.e.p. at speeds over 3500 r.p.m. but actually substantial decrease have resulted at speed below 3500 r.p.m. This may not apply to other heads and each of the various types of head will be examined similarly. With regard to the effect of forced turbulence on detonation, a ramp head to drawing No. LeC.4137 is being made having the maximum Forced turbulence ratio (1.97) possible with this design. When this is tested we shall be | ||