Rolls-Royce Archives
         « Prev  Box Series  Next »        

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).
Comparison of the Wraith III Stromberg carburetter against a standard version, detailing ten differences.

Identifier  ExFiles\Box 7\4\  X 608 Carburetter-page42
Date  26th October 1938
  
Da.{Bernard Day - Chassis Design}
Da{Bernard Day - Chassis Design}/Mc.S.21/G.26.10.38.

WRAITH 111 - STROMBERG CARBURETTER.

With reference to the recommendations made in
Rm{William Robotham - Chief Engineer}/4/R.4.10.38. and Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation}6/R.6.10.38. re the bringing of
the Wraith 111 carburetters nearer to the standard Stromberg
carburetter with a view to reducing the price, we are asked
to pay for them. We give below a list of differences
existing between our present Wraith 111 carburetter and a
standard Stromberg carburetter with reasons for the
differences.-

(1). Throttle and Choke Levers to suit R.R. Controls.

(2). Hexagon headed screws for throttle body joint, for
main jet cap, and for float spindle. We have had
experience in each of these cases of the parts being
insufficiently tightened by screw driver in the
Stromberg standard cheese heads and becoming loose
in service.

(3). Nut at operating end of throttle spindle to retain
lever instead of riveting owing to poor job of
riveting on earlier carburetters.

(4). Improved fast idle connecting link to give increased
bearing life and more definite fixing.

(5). Fast idle cam with better finish and hardened face.

(6). Improved bearing for choke operating lever to give
longer life to lever and maintain fast idle setting.

(7). Collar and split pin instead of washer and split pin
for controlling end movement of choke spindle to give
increased reliability.

(8). Aluminium joint washer for main jet cap instead of
fibre, as fibre washers are not used by R.R.

(9). Stainless steel accelerator pump rod instead of mild
steel to prevent corrosion and sticking, which has
been experienced in service.

(10). Stronger choke valve with increased diameter spindle,
spring loaded in closed position, with reversed release
valve, and bearings counterbored, all to remove risk of
seizure of choke as experienced through the various
causes in service.
  
  


Copyright Sustain 2025, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙