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).
10,000-mile report on engine unit B7, detailing performance and component conditions.
| Identifier | ExFiles\Box 82\2\ scan0132 | |
| Date | 1st August 1934 | |
| 46583 a 9C Rep A.6. Shute C Hotel de France, Chateauroux. Indre. France. 1st August 1934. TO EG.✓ From G.W.H. c. WOR.{Arthur Wormald - General Works Manager}✓ c. H.J.✓ c. H.S.✓ 4 B IV. 10,000 Mile Report. ENGINE UNIT N* B7. The engine has remained good for power and acceleration, with the crank damper load set to 19 lbs. at 17 1/2" radius, the half crankshaft period, and period at 3,750 were smoothed out, making the engine smooth throughout the range. Compressions were even and good. Detonations, although reported, were not of such a nature that would be objected to, and could be cutout by the judicious use of the ignition lever. Azure petrol was slightly less inclined to detonate. Oil consumption was small with the high speeds maintained, the average for the mileage being 1,528.- Petrol consumption was up to standard, being 14.21 M.P.G. The engine started up with ease, and a get-away was possible immediately. It remained fairly clean, actual oil leaks being small. We ran into trouble with the double taper valve spring breaking, which was aggravated by decreasing the valve clearance to HS{Lord Ernest Hives - Chair}/RM{William Robotham - Chief Engineer}'s instructions of the 20/7/34. PISTONS AEROLITE WITH SPECIAL GRINDING. The pistons have remained free from knocks, hot or cold; compressions even and good, very little sign of over oiling when idling. Piston heads had only a very small amount of carbon deposit. VALVES AND FITTINGS LOP. EB.141. LEC. 3873 SUPPORT RING FOR VALVES. INLET VALVES S/SLV. EXHAUST VALVES KE.985. The valve clearance was reduced to .004 --- .003 Loss of clearance or otherwise could not be obtained due to valve spring failures. When taken out and examined, the exhaust valves showed definite traces of burning opposite the ports and also gave indications of being off their seats. Inlet valves were in good condition, but too much oil had been passing down the stems. Nos. 1 and 2 bottom tappets were taken out and examined to ascertain the cause of springs breaking. | ||