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).
Technical memorandum on the design of the Curtiss Conqueror engine, focusing on cylinder construction, supercharging, and starting systems.
| Identifier | ExFiles\Box 173\1\ img174 | |
| Date | 20th January 1934 | |
| q. Indianapolis, Indiana. January 20, 1934. HS{Lord Ernest Hives - Chair}/RH{R. Hollingworth} o S/RW. 373 H.{Arthur M. Hanbury - Head Complaints} S. from R.{Sir Henry Royce} H.{Arthur M. Hanbury - Head Complaints} C. CURTIS CONQUEROR Cylinder Construction Present cylinder design is a source of trouble, chiefly on account of manufacturing difficulties. Extreme accuracy in machining of cylinder liners and head is necessary since roof of liner must fit perfectly to cylinder head.⊕ The machining of threads must be perfectly square so that in final assembly liners are perpendicular. [Handwritten: @Conductivity must be poor] Owing to the difficulties which are encountered, alternative cylinder construction has been designed, which consists of separate all steel cylinders, having six holding-down bolts at base flange, and jacket made in tubular form braised in position. Whereas this arrangement has not been subjected to type Test, development experience is most satisfactory. The valve [Handwritten: Part] projecting on top of liner provides spigots for location of cylinder head, which is one piece aluminum casting. The water jacket is made tubular steel form having three corrogations and cylinders diameters are stepped so that jacket can be threaded to position. This construction has been made possible due to progress of hydrogen braising which is now being used ~~extensively~~. Parts to be braised are copper plated, both internally and externally. After jackets are fitted and unit is prepared for braising, it is placed in a hydrogen furnace and heated to 1100C and braising automatically takes place, no fluxing being necessary. So far this design has proved to be thoroughly reliable. Local stress in cylinder jacket does not occur since braising temperature is uniform. Production costs are very much lower [Handwritten: FROM] than original aluminum design, and decidedly lower than original arrangement of built up steel jackets, which required so much hand work. The butt-ended cylinder liners prevent introduction of valve inserts in alternative materials. [Handwritten: LOOSE TYPE] Super Charger The blower drive is taken from spurger [Handwritten: SPUR GEAR] at front of engine through long flexible drive to super charger, which is dropped below the crank shaft [see sketch]. Super charging is carried out by blowing through the carburetor which is ~~arranged~~ between cylinders. By lowering super charger arrangement of auxiliaries is much more compact. Starting The Americans are now adopting electric starters for [Handwritten: ALL] engines. Curtis Wright have been using on the Conqueror an electric starter with reduction gear ratio. | ||