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).
Bentley heat balance experiments, detailing the unit specifications and testing methodology.
| Identifier | ExFiles\Box 131\1\ scan0126 | |
| Date | 13th February 1934 | |
| To Sg.{Arthur F. Sidgreaves - MD} From Hs{Lord Ernest Hives - Chair}/Mths.{Reg Matthews} c. to Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} c. to Sg.{Arthur F. Sidgreaves - MD} c. to Hy.{Tom Haldenby - Plant Engineer} c. to Lr.{Mr Ellor} 4766 1114 (No 3) Hs{Lord Ernest Hives - Chair}/Mths.{Reg Matthews}1/RW.13.2.34. BENTLEY HEAT BALANCE EXPERIMENTS. We have recently carried out experiments to determine the distribution of heat on Bentley units and our results are shown graphically on appended chart. The specification of the unit these tests were carried out upon was as follows :- (1) Fully balanced Crankshaft (Chrysler type Balance Weights) with white metal bearings. (2) Duralumin Connecting Rods (EX.12396). (3) High compression Cylinder Head (6.9:1). (4) E.B.1299 Pistons. For complete specification see NRC{N. R. Chandler}/WSC.{W. S. Cassel}9/AP6.12.33 for B.6 unit. The method of determining the Heat Balance figures was as follows :- (1) The engine was run at 4,000 r.p.m. full throttle with mixture set at weakest maintained. From this we determined the initial fuel energy, namely, 18,300 B.T.U's/minute. (2) From the B.H.P. we arrived at a figure for the Effective Motor Power. (3) By cutting out each cylinder in turn we found the I.H.P. and by deducting from this figure the B.H.P., we arrived at the total friction and pumping losses. (4) HEAT TO OIL. The total heat to the oil was determined by measuring the total flow of oil and the temperature rise across the engine with the cooler set to maintain a steady inlet temperature of 90°C. By measuring the release oil flow and the temperature rise we determined the amount of heat picked up by the oil from the oil pump and gears etc. | ||