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 a supplier discussing a reported failure of a distributor cam and its material properties.
| Identifier | ExFiles\Box 168\3\ img009 | |
| Date | 10th November 1938 | |
| DELCO-REMY & HYATT LTD. Head Office & Works: 111 GROSVENOR ROAD, LONDON. S.W.1 Telegrams: DELREMYHYAT, SOWEST, LONDON Telephones: VICTORIA 6242 (7 LINES) Messrs. Rolls Royce Ltd., Derby. Attention of Mr. W.A. Robotham YOUR REF. Rml1/R OUR REF. WAC/PG 10th November..1938 Dear Sirs, Your letter dated 9th instant, marked for the attention of Mr. Rushton, has been handed to the Undersigned for reply. We, also, regard this matter as very serious and regret exceedingly that your Works Director has been inconvenienced by a failure of one of our Delco distributors which you attribute to a low brinell cam. You refer to the fact that after about 2½ years experimental work the Delco distributor behaved satisfactorily on your engines. You then requested us to use Tufnol rubbing blocks. Is it not natural to assume, therefore, that the subsequent trouble which you have recently reported may be due to the only change made since satisfaction was achieved, viz., to the rubbing block material? The fact that the cam which proved satisfactory happened to have a brinell hardness of over 400 is, we suggest, incidental, for no attempt is made by us, and never has been made, to keep cam hardness to any specific brinell. It has never been necessary to do so when our standard material rubbing blocks are used which, as Mr. Rushton pointed out in his letter of the 7th instant, are even satisfactory when used on 9-cylinder aircraft engine distributor cams unhardened. | ||