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).
Cooling system tests for a Bentley B.56.BN car at Brooklands race track.
| Identifier | ExFiles\Box 87\1\ scan0226 | |
| Date | 5th May 1937 | |
| To E.{Mr Elliott - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Std. c. By.{R.W. Bailey - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} c. Da.{Bernard Day - Chassis Design} 240 Rm{William Robotham - Chief Engineer}/Std.1/AP.5.5.37 REPORT ON COOLING TESTS CARRIED OUT ON B.56.BN.{W.O. Bentley / Mr Barrington} CAR AT BROOKLANDS. We recently carried out tests at Brooklands track on the above car to determine - (1) Adequacy of cooling system on standard 4¼ litre Bentley car (with standard 58 MM. Mk.V. matrix.) (2) Critical air temp. on std. 4¼ litre Bentley with 58 MM. Mk.Vl{V. Lewis / Mr Valentine} matrix of lightened construction - this construction consisting of .003" untinned airway strip and .005" tinned waterway strip instead of the standard .004 tinned airway strip and .006" tinned waterway strip. (3) Critical air temp. on std. 4¼ litre Bentley with 52 MM. Mk.Vl.{V. Lewis / Mr Valentine} matrix of same construction as in (2) BUT UNTINNED AIRWAY. (4) Minimum angle of opening of shutters to give adequate cooling with either of the matrices in (2) and (3) (5) Relative cooling effectiveness of two types of pressed sheet construction fan blades. Results of Fans. These are shown on attached sheets as are also the best lap and half mile speeds. Conclusion from Tests. (1) Standard cooling system on the 4¼ litre Bentley is quite adequate, the critical air temp. being approximately 42°C. This confirms our estimate and indicates that the matrix tested in Rm{William Robotham - Chief Engineer}/Std.4/AP.4.3.37 (an old early one) was defective - it will be examined when it is returned from France. (2) The Mk.V.l. type of core with lightened construction shows a gain in cooling over the Mk.V. type, especially at low speeds, but within limits of experimental error no difference could be detected between the 58 MM. and 52 MM. cores. However, the weight difference of these cores is also small, dry weights being respectively 24 and 23 lbs. continued | ||