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).
Report page detailing engine component troubles and testing procedures for blowers.
| Identifier | WestWitteringFiles\O\2January1926-March1926\ Scan37 | |
| Date | 28th January 1926 guessed | |
| contd :- -5- to the blower intake pipe, between the blower and the carburetter. Each blower was tested separately before mounting on the engine, curves for H.P. absorbed at various pressures and free flow delivery being taken. At 5000 r.p.m. and 8 lbs/sq.in. back pressure,16.5 HP. was required to drive the blower when delivering mixture as in the engine. REMARKS. One of the chief troubles at the outset was failure of the exhaust valves owing to the excessive heat flow into them. This is not necessarily due to a high temperature (for actually, the temperature of the burnt gases would not be so very much higher) but more on account of the greater quantity of burnt charge passing. The steel used was known as 'B.B', but many other kinds have since been tried. The steel in use at present 'Urenus' (Hadfields), appears to be giving very satisfactory results. Plug trouble was also experienced, K.L.G. 221s are at present in use and seem capable of standing up to the abnormal conditions. A rich mixture has always been favoured - generally reckoned about 12/1 air/petrol by weight to obtain a cool engine. Pistons, at first, gave considerable trouble - crack-ing and sometimes 'holing' in the crown. This trouble was pract-ically eliminated by strengthening up the webs between each gudgeon pin boss and the crown, and contd :- | ||