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).
Test of Studebaker gear change and overdrive systems for engineering insights.
| Identifier | ExFiles\Box 128\1\ scan0351 | |
| Date | 24th June 1938 | |
| 1104 also 1153 To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} c. Sg.{Arthur F. Sidgreaves - MD} c. Hs.{Lord Ernest Hives - Chair} c. Da.{Bernard Day - Chassis Design} c. Hdy.{William Hardy} STUDEBAKER GEAR CHANGE ARRANGEMENTS. Yesterday Rm.{William Robotham - Chief Engineer} and I borrowed from Hoopers two Studebaker cars, a 1937 8-cylinder and a 1938 6-cylinder. The 6-cylinder car had the vacuum assisted gear shift mounted on the instrument board, and the usual Warner overdrive cutting in automatically above 40 m.p.h. From the point of view of a central change the small gear lever has eliminated an obstruction in the middle of the front compartment. As arranged by Studebakers the lever knob has about 3½" travel from top to 2nd. The effort to change gear was very little less than on a Wraith. A considerable part of the benefit of vacuum assistance is lost in the increased friction losses of remote control. With the engine stopped, and therefore no depression in the manifold it was only just possible with enormous force to engage top gear. As proposed for test on a P.III where the gear lever will remain a right hand change but with shorter travel, we shall benefit more than Studebakers by the servo assistance. Moving the lever across for 1st. gear was not easy. One quite often got top instead of 1st. Changing into first was a heavy operation and the teeth were prone to crash. In no way is this memo intended to disparage the Studebaker scheme. The object of the test was to discover some engineering points for the benefit of the Design Department. The 1937 8-cylinder car had an inertia type overdrive. Its operation is roughly this: above 30 m.p.h., if the throttle is closed, overdrive automatically engages. Overdrive then stays in engagement either pulling or over-running at any speed above 10 m.p.h. provided the throttle is always opened gently. At any speed direct can always be got by closing the throttle and then opening it quickly to its full extent. If it is closed above 30 m.p.h. overdrive again engages. | ||