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 cooling problems and cylinder head design.
| Identifier | ExFiles\Box 149a\3\ scan0195 | |
| Date | 7th October 1936 | |
| HARRISON RADIATOR CORPORATION LOCKPORT, NEW YORK October 7, 1936. -4- As a matter of interest, when the Chevrolet people first contemplated producing a 6 cylinder car in place of the 4, we were given the task of cooling more satisfactorily the 6 cylinder engine with the four cylinder radiator. With the cooperation of the Chevrolet Eng. Department and upon our suggestion various cylinder heads were designed and made up and you will note particularly upon examination of the present cylinder head of the Chevrolet that the exhaust ports are not completely surrounded by water to the point where the exhaust pipe is attached. This permitted us to so reduce the heat output from the jacket that we were able to meet this cooling specification laid down by the Chevrolet Company. Of all the troubles to which the present day motor car is heir, the two problems which are discussed with bated breath are weak frames and steam pockets in the water jackets. This over here particularly is a very personal matter and is approached with great deal of hesitation. Candidly, in the most constructive manner possible, would like to suggest that if you are getting away with the cylinder head design which you now have, it is entirely due to the skill of your Foundry men in producing such exceptionally thin water passages. We would not, over here, approve for production of our type, a design in which the passages, as previously stated, were less than a minimum of 3/8" in width and also as previously stated, we do not like to have less than 1" of water, preferably 1-1/2", over the exhaust port, as we find that this is one of the most prolific sources of trouble, insofar as flashing of water into steam is concerned. Believe it would be advisable on your part, if you have not already done so, to cut up some cylinder heads to find out what core shifts have taken place and believe that you may find some places where the core wires have fused to the cylinder head proper, some potential sources of this trouble being shown on your drawing. Also, believe that in some places, it may be advisable to eliminate the water passage altogether, which will not be detrimental to the performance of the engine and will, at least, remove a potential source of the trouble. The cylinder head drawing which you forwarded is not complete, as you are aware, however, will return this to you through Mr. Dunn who we are looking forward with pleasure to seeing. Will go over with him in detail some of the points mentioned in this letter and will mark-up the print so that Mr. Dunn may carry back to you his impressions of our conversation on this subject. If Mr. Dunn has any specific questions will be pleased indeed to take care of him to the best of our ability and wish to assure you that we stand prepared to give you any assistance we can at any time. Yours very truly HARRISON RADIATOR CORPORATION L. P. Saunders. LPS:LJH. HEAT TRANSFER PRODUCTS RADIATORS . SHUTTERS . AVIATION . AUTOMOTIVE . MARINE . INDUSTRIAL OIL TEMPERATURE REGULATORS . CAR HEATERS . THERMOSTATS . HEAT EXCHANGERS | ||