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 to a supplier concerning oil cooler testing, failures, and design modifications.
| Identifier | ExFiles\Box 131\1\ scan0242 | |
| Date | 20th November 1936 | |
| 12-80 11/4 Experimental Department 20th November 1936. Rm{William Robotham - Chief Engineer}/Std.6/AP. Messrs John Marstons Ltd., WOLVERHAMPTON. For the attention of Mr.Dunn. Dear Sirs, We send you herewith our drawing E.88558 which shews the strengthened top plate for our oil cooler. This is to confirm that you will make us up an oil cooler with this new type of top plate, as discussed with you yesterday - we will send you the special unions as soon as they are finished. Before you send us this cooler, we should like you to test it against a standard oil cooler for relative distortion of the seating surfaces under a pressure of 200 lbs/Sq.in. (preferably unsupported by a surface plate) - this could be done before final machining of these surfaces. We have tested the eight coolers which the writer brought back with him and find that our tests correspond with yours i.e. none of these coolers leaked under 200 lbs/Sq.in. pressure cold. We are therefore returning these coolers to you for final machining and fitting of grids. We have examined the cooler which burst on a customer's car in service and find that the breakage is at the edge of the bottom plate - also that it was an early cooler of yours (No.E.4.) and had not been pressure tested by us. We have also been informed today that a second cooler has failed in service, but have not yet been able to examine same. We should like to summarise the oil cooler situation as we see it at the moment, as follows- 1. The troubles which we are experiencing with oil coolers are (a) Rejection of coolers owing to pressure leaks under test. (b) Rejection of coolers owing to union faces not in one plane. (c) Failure of coolers in service - i.e. leaks occurring. continued | ||