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).
5000-mile test report on I.B. IV, detailing engine performance, oil consumption, and piston knock issues.
Identifier | ExFiles\Box 82\1\ scan0265 | |
Date | 13th October 1933 | |
To Hs.{Lord Ernest Hives - Chair} From G.W.H. Hotel de France. Chateauroux. Indre. 13.10.33. REPORT ON I. B. IV. - 5000 MILES ENGINE UNIT New B.4. The power and acceleration has remained good. There has been no difficulty in starting up in a morning. A quick get away could be got by placing the mixture control two to three notches from normal. This could be moved to normal running position in approx. 15 minutes. The oil consumption was high for the first two days running. It was getting past the piston rings and being burnt. The consumption improved with running and settled down to approximately 1000 miles per Gallon. The engine has been smooth and free from half crankshaft period up to 4000 revs. At this speed and over it became very rough. Timing gears have been free from rattles, with engine idling and when accelerating. PISTONS LOP - 6. EB.495 A/P-404 - special cast and heat treatement ground to drg. Ex.11480. An intermittant piston knock was heard during the third days run (1500miles) After 3200 miles it became more prevelent and could be heard distinctly. At 5000 miles it was a distinct knock. The actual piston could not be located by the usual method of shorting the plugs. By listening it appeared to come from number three. We have dismantled the engine and examined the pistons. The Knock is apparantly due to slap sideways as we find that numbers 4,5, and 6 pistons had the skirt gone egg shape, the narrow portion being at right angles to the slot. There was no sign of any cracks on any pistons. The bedding showed very hard at the top of the skirt. CONNECTING RODS Complete to Gen. Arrgt. EB.864. incorporating Loc.3556 - Oil tube fixing. | ||