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 Ethyl Export Corporation discussing the condition and material composition of Cadillac V-16 engine valves.
| Identifier | ExFiles\Box 150\1\ scan0037 | |
| Date | 3rd June 1935 | |
| ETHYL EXPORT CORPORATION THAMES HOUSE, MILLBANK, LONDON S.W.1 June 3rd, 1935. Mr. R.{Sir Henry Royce} R.{Sir Henry Royce} Banks, Ethyl Export Corp. Dear Rod, Many thanks for your letter of April 11th regarding the valves taken from the 16-cylinder Cadillac which Rolls Royce used on their standard test on continental roads in France. The people I have discussed this with at the Cadillac factory have very little to say except that it looks much worse than they would expect the V-16 valves to look after 20,000 miles of operation regardless of the severity. Mr. Seaholm, Chief Engineer, has been away and will not return until next week. I will discuss this matter with him and perhaps he will have more definite statements and I will then again communicate with you. Sam Heron thinks the valve looks terrible but also points out that the amount of deposit on the stem at the point where the valve leaves the guide is greater than that which we normally experience in this country and suggests that the car might have been operated on "some rotten British oil". There is little doubt in my mind that the build-up on the stem caused the valve to hold open and burn so badly. The valve is made by Wilcox Rich and is of Silchrome No.1 material Carbon .45 Manganese .40 Silicon 3.25 Chromium 8.50 Phosphorus .035 max. Sulphur .035 max. The Cadillac Company use Silchrome No.1 valves in most all of their engines, Thompson and Wilcox Rich being the suppliers. They have also purchased a few valves from the Detroit Motor Valve Company of two-piece construction using Uniloy No.2 for head material and S.A.E. 3140 stems. I think you know Uniloy No.2 is- Carbon .30 Manganese .85 Chromium 21 Silicon 1 Nickel 11 At least unofficially the Cadillac engineers lean slightly towards the austenitic exhaust valve but also feel that Silchrome No.1 is giving quite satisfactory results. In other words, both of these steels are on the approved list and because of price Silchrome No.1 naturally predominates. It is my understanding that none of the Uniloy No.2 valves have ever been used in the V-16. Very truly yours, (signed) JULIAN J.{Mr Johnson W.M.} FREY. | ||