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).
Calculation of critical air temperature for a Bentley using a Marston Mark VI matrix at full throttle.
| Identifier | ExFiles\Box 149a\2\ scan0265 | |
| Date | 7th November 1935 | |
| (Appendix - Sheet 4) HS{Lord Ernest Hives - Chair}/Std.14/KW. 7.11.35. Calculation for Bentley (85 m.p.h. Full Throttle) using Marston Mark VI 52 m.m. Matrix. From test figures (sheet ) heat dissipation at 85 m.p.h. = H / Δt = 90 B.T.U's/min/°C. temp. difference between inlet air and water. Assuming same reduction of cooling due to under bonnet pressure as in case of SpectreCodename for Phantom III, actual heat dissipation = .936 x 90 = 84.3 B.T.U's/min/°C. temp. difference. H = 3600 B.T.U's ∴ Δ = 3600 / 84.3 = 42.7°C. ∴ Critical air temperature = 100 - 42.7°C. = 57.3°C. NOTE: Brooklands tests gave critical air temperature figure of 52°C. Similarly, using Mark V 58 m.m. matrix (as standard at present) under same conditions, Critical air temp. = 53.2°C. NOTE: Brooklands tests gave figure of 48°C. | ||