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 engine heat output, radiator core sizes and cooling system design.
| Identifier | ExFiles\Box 149a\3\ scan0194 | |
| Date | 7th October 1936 | |
| HARRISON RADIATOR CORPORATION LOCKPORT, NEW YORK October 7, 1936. -8- Am enclosing a marked-up print of the heat output characteristics of one of our cores, which explains definitely why you get the improvement you do by running a more effective fan at a higher speed. Over here, we have two objections to this method of solving the problem, one is noise previously mentioned and the second is excessive horsepower which we find does affect the fuel consumption of the car as a whole. Referring to heat to the water jacket, was not aware that you had part of the exhaust ports water-jacketed which obviously will increase very materially your heat output rate. You may be interested to know that some years ago the Reo Company prior to producing the "Flying Cloud" model, sent us the specifications for a radiator for this engine in the experimental stage. We were not permitted to see this engine and contrary to our usual custom, we found it necessary to make additional cores having an increase in total heat rejecting capacity in an endeavor to cool the experimental cars which were running. We started by forwarding a radiator having a core 2-3/4" deep and then went to 3" to 3-1/4" and finally 4" which did not have sufficient capacity. Upon calling to the attention of the Reo Engineering Department, the fact that they were buying more core for this particular car than was used by similar engines of a like displacement, they permitted us to inspect the engine in question. We found that the heat increase output from the jacket was caused entirely by an increase of approximately 1-1/2" over standard practice here between the face of the cylinder block to which was bolted the exhaust pipe and the center of the exhaust valve on the 6 cylinder engine, representing nine additional lineal inches of water heated surface which was putting heat into the radiators. Upon cutting this dimension down, 1-1/2", we were able to cool the car quite satisfactorily with a 3-1/4" radiator. Again referring to the increase in load imposed on the cooling system by passage of the exhaust pipes through the water jacket, at 60 MPH a car having an overhead valve type of engine of approximately 220 cu.in. displacement put 2200 BTU/MIN into the jacket. The Ford engine of the all type, which should put in not more than 20% increase due to the type of cylinder head design at the same speed and under the same test conditions, puts in excess of 5000 BTU/MIN into the jacket. The increase entirely being due to the water jacketed exhaust pipe which passes completely through the cylinder block. HEAT TRANSFER PRODUCTS AVIATION AUTOMOTIVE MARINE INDUSTRIAL RADIATORS SHUTTERS OIL TEMPERATURE REGULATORS CAR HEATERS THERMOSTATS HEAT EXCHANGERS | ||