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).
Letter from Harrison Radiator Corporation discussing radiator core performance and design.
| Identifier | ExFiles\Box 149a\3\ scan0156 | |
| Date | 24th January 1936 | |
| *X1278 HARRISON RADIATOR CORPORATION LOCKPORT, NEW YORK January 24, 1936 Rolls-Royce Limited Derby Derbyshire, England Attention: Mr. C. S. Steadman Reference: Hs{Lord Ernest Hives - Chair}/Std. 9/KW. Dear Mr. Steadman: Am pleased to learn as per your letter of January 7th that there is a possibility we may receive a Chausson Gallay type of radiator block for test purposes. Answering your question concerning the respective merits of the Mark V and Mark VI, over here we do not find any difference in performance between the two types of cores at maximum speed. The Mark VI was developed to provide increased cooling at low speed, tests having shown that this change in ratio of direct to indirect surface was beneficial for low speed cooling only. This condition exists regardless of the depth of the radiator and would suggest that if you have a difference as outlined, the reason will unquestionably be found to be due to a poor solder bond on the core which was the hottest. Regarding the difference in dissipation expected between a 52 and 58 m.m. core, we have found over here that this difference is so slight as to be imperceptible on the road. Answering your second question as to whether or not the Mark VI core is the best design which we have at present, wish to advise that a still later design is now in production over here, the constant on the Mark VI being 20 x 55 and on this later type of core 18x 62. This gives us an increase in surface for the same weight and still further boosts the low speed cooling. However, the high speed cooling remains the same as that obtained with the other constant. In connection with still further increase in dissipation, wish to advise that our 4" core gives an increase over the 84 m.m. core of approximately 15% at 60 miles per hour. HEAT TRANSFER PRODUCTS RADIATORS . SHUTTERS . OIL TEMPERATURE REGULATORS . AVIATION . AUTOMOTIVE . MARINE . INDUSTRIAL . CAR HEATERS . THERMOSTATS . HEAT EXCHANGERS [Handwritten notes:] STD Hold by/STO | ||