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 Wilcox-Rich Corporation regarding difficulties with hydraulic lifters and suggesting a design change.
| Identifier | ExFiles\Box 173\2\ img212 | |
| Date | 20th February 1934 | |
| COPY WILCOX-RICH CORPORATION, DETROIT, MICHIGAN. February 20, 1934. Mr. W. A.{Mr Adams} Robotham, Rolls-Royce of America, Inc., 34, East Fifty-Seventh Street, New York City. Dear Sir, Mr. Jardine has referred to me your letter of February 17. Regarding the difficulty Rolls-Royce have experienced with the hydraulic lifters' gradually lifting the valve, we anticipated the possibility of this trouble while working on a design of lifter for this setup, which we attributed to the use of an auxiliary spring to hold the lifter body down to the cam. This prevents the inertia of the lifter body entering into the valve train at floating speed so that floating occurs in the hydraulic unit rather than between the face of the roller and the cam. We have had no previous experience with this sort of trouble, as we have not previously worked on a job where this spring was used. May we suggest that you attempt a design in which this spring is omitted, which will correct this difficulty? Incidentally, the valve spring, when used with hydraulic lifter, may be considerably increased without excessive hammering of the valve on the seat, and this may make possible a design, as mentioned above, without the spring holding the lifter body against the cam. In the event this cannot be accomplished, it appears to me to be necessary to eliminate your floating entirely. I would be very glad to see you on your next visit to Detroit. Perhaps you will remember some three years ago I conducted you through the Pierce-Arrow Plant and showed you what progress we had made at that time in the development of hydraulic lifters. Trusting the above information will assist you in eliminating your difficulties, Yours very truly, WILCOX-RICH CORPORATION, (Sgd.) Carl Voorhies. CV:TB. | ||