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).
Summary of design issues with the Ph.III cylinder head water-ways and proposals for redesign and further testing.
| Identifier | ExFiles\Box 93\4\ scan0036 | |
| Date | 29th June 1936 | |
| -4- Hs{Lord Ernest Hives - Chair}/Std.10/KW.29.6.36. Summary. The water-ways on the Ph.III cylinder head are fundamentally bad from a design point of view, and should be rectified at the earliest possible moment. Consideration of the drawings indicates that the waterways communicating between the exhaust and inlet sides of the Bentley head are much more generous, although in this case, longitudinal flow takes place on this head and the transverse waterways are not so important. The worst waterways on the Ph.III head are between the exhaust and inlet ports of each combustion chamber; the next worst are between pairs of inlet ports, and the best are those between pairs of exhaust ports. The deficiencies show up particularly on portions of a head which we have sectionned. At present, the production unit test beds are turning down any Ph.III heads which show a temperature difference between rear of head and outlet greater than 6°. However, as they are only able to test the 'A' side block in this manner, the rejected heads reappear as 'B' heads and so pass the unit test. This is of course wrong but at the moment there seems to be no useful purpose served in scrapping such heads, since in all probability a number of the 'B' heads on engines passed off test are of this character. Further, no harmful result has shown up from running such heads, the only disadvantage on 'A' side being that the thermometer reading on the dashboard is thus made much too high. The arrangement of water holes shown on Rm.{William Robotham - Chief Engineer}168 should be standardised as soon as possible in order to reduce the temperature differences to a minimum, pending redesign of head. We propose to carry out similar local temperature investigations on Bentley and 25/30 HP. cylinder heads. Hs{Lord Ernest Hives - Chair}/C.S.Steadman. | ||