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).
Issues with Bensport exhaust valves, including stretching and overheating, and proposing alternative port designs.
| Identifier | ExFiles\Box 88\4\ scan0001 | |
| Date | 26th May 1932 | |
| Y 254- To H.{Arthur M. Hanbury - Head Complaints} from E.{Mr Elliott - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} re Bensport Exhaust Valves. We understand from Hs{Lord Ernest Hives - Chair}/GWH{George W. Hancock - Head Chateauroux} that the exhaust valves, Nos. 2 and 5 are always the first to give trouble as regards stretching when detonation is present. It was these two valves that gave trouble on 19-EX recently until the sparking plugs were altered for another pattern. With the exhaust bends coupled in pairs Nos. 2 and 5 valves begin to open just before 1 and 6 close, and this may be a reason why the former valves are apparently hotter than the rest. 3 and 4 are evenly spaced, and so far as we know are no worse than 1 and 6. In the case of the supercharged engine the exhaust valves are going to get still hotter, and it therefore suggests considering whether six separate exhaust ports could be arranged. This does appear to be the case, and we attach herewith a sheet showing a number of possibilities, diagram "A" being the present arrangement, "B" a five port exhaust and "C" to "G" various six port designs. We should endeavour to group the exhausts externally in threes, and have two downtakes, which would be a very good arrangement for a sporting engine. The downtakes would have to be arranged one each side of the dynamo, and the water pump would occupy a position in front of the forward downtake. The exhaust arrangement shown in "C" and "D" diagrams, although they appear to lengthen the head | ||