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 performance and cooling for the Phantom III and Bentley engines.
| Identifier | ExFiles\Box 149a\3\ scan0176 | |
| Date | 18th August 1936 | |
| HARRISON RADIATOR CORPORATION LOCKPORT, NEW YORK August 18, 1936 [Handwritten top left]: X1278 [Handwritten top right]: Noted Hs{Lord Ernest Hives - Chair}/STD Mr. Steadman Rolls Royce Limited Derby, Derbyshire England Reference: Hs{Lord Ernest Hives - Chair}/Std.17/KW Dear Mr. Steadman: Please accept my apologies for this belated reply to your letter of June 16th and in extenuation wish to state that in addition to being exceptionally busy have found it necessary to be out of town for some time on business. Answering your questions in the sequence outline in your letter of the 16th. First, concerning the question of the cooling of the Phantom III car adequately with the size of radiator which you have corresponding as stated in previous letter to .3 lbs/HP. The figure which you give for the weight of this radiator core namely, 54 lbs. is the weight of the 4" core as manufactured by us over here. The 3.3" core for the frontal area should not weigh more than 41-1/2 lbs., however, assuming two things, first that the core dissipation is up to par and second that the heat input to the jacket is down to a satisfactory figure, the core weight figures out at .275 lbs./HP. [Handwritten in left margin]: what about this? Regarding the BTU input to the jacket of the Bentley and the Phantom engine respectively, the Bentley has an input of 33.3 BTU to 39.3 BTU per HP/Min. to the jacket, the first figure being at 60 MPH and the second at 90 MPH. The Phantom, however, has an input from 46.6 at 60 MPH to 69.5 at 90 MPH. The Phantom figures being approximately 10 to 12% higher than those put into the jacket of cars over here, fitted with overhead valve engines. [Handwritten in right margin]: We must account for this difference The waterflow curve has been gone over carefully and find that the temperature rise across the engine ranges from 27.5° at 30 MPH to 18.9° at 90 MPH. These figures are sufficiently high that the water volume can be doubled with a resulting decrease in top tank temperatures of approximately 7° at 30 MPH and 5° at 90 MPH. These figures being Fahrenheit. [Handwritten at bottom]: We shall get a faster water-pump on the Continental Phantom, shall we not? It will help us in our worst place, i.e. low speeds. [Footer] HEAT TRANSFER PRODUCTS AVIATION AUTOMOTIVE MARINE INDUSTRIAL RADIATORS . SHUTTERS . OIL TEMPERATURE REGULATORS . CAR HEATERS . THERMOSTATS . HEAT EXCHANGERS | ||