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 a Bentley 3.5 Litre B.56 engine, detailing performance and component wear.
| Identifier | ExFiles\Box 83\4\ scan0030 | |
| Date | 2nd November 1935 | |
| X 264a To. [REDACTED] from Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} c to. [REDACTED] c to. [REDACTED] c to. [REDACTED] c to. [REDACTED] c to. [REDACTED] c to. Hs.{Lord Ernest Hives - Chair} BENTLEY 3.5 BORE B. 56. EN. REPORT AT 10,000 MILES Specification to RHC{R. H. Coverley - Production Engineer}/CP.I/EP.{G. Eric Platford - Chief Quality Engineer} 4.10.35. The acceleration and maximum speed of this Car is a revelation over the present standard Bentley. The performance is such, that a steady 80 MPH. can be run with the same amount of smoothness that is now obtained at 70 MPH, with the present Cars. A maximum speed of 101 MPH. was reached with the fitting of the L.B.I. Needles, with a corresponding decrease in petrol consumption. The Car can be kept under perfect control at this speed. The smoothness of the Engine was improved by attention to the rubber mounting, i.e. lessening the tension on the rear feet, and setting the damper rubbers evenly behind the Gearbox. Slight detonations have been noticeable up to 40 MPH. There is a flywheel whistle. ENGINE. B.18 UNIT (3.500) BORE. There has been no trouble in starting up cold. The minimum temperature in the garage 3°c. At maximum speeds there has been no sign of falling off in power. The cleanliness is fair. There has been an oil leak from the rear rocker cover joint, and a slight leak from the Cylinder joint at the rear. The bottom of the Ignition Tower became covered with oily aluminum swarth. It has remained free from any marked crankshaft period. At a mileage of 7,144, the release oil pipe feeding the timing gears broke at the joining of pipe to banjo connection. The change of section being too sudden. We dismantled the Engine to examine the Pistons, Valves, and Connecting Rod Bearings. PISTONS. "AEROLITE" TYPE. There was no sign of failure. The rings were free. The bedding was full on the pressure and non pressure sides. The ring lands were clear. A normal amount of carbon deposit was found on the Piston tops. The Gudgeon pins were free with no noticeable wear. CONNECTING RODS. LOT EB.2260 LEC 4281. HALLS WHITE METAL BEARINGS. The bearings of four rods were in a good condition, free from surface marks. N° 2 & 3 rods show failure of the bearings. On N° 3 the metal is cracking up on the top half, several small pieces having detached themselves after dismmantling. The bottom half is sound but shows markings of fine pieces of metal having been pressed in. On N°2 the top half is in a good condition, the bottom half, a small piece approximately .375 in diameter came out when dismantled. | ||