FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1935
1935 - 1420.PDF
SUPPLEMENT FLIGHT. JUNE 13, 1935. h be he a private individual or a commercial operator, not to men tion the ground engineer, whose work should be comparatively light during the long periods between overhauls. Beyond normal main tenance and routine inspection there should be very little for an engineer to attend to. The inversion of the new engine has necessitated a new lubrication system. From the illustrations can be seen the arrangement of the oil pump and filter casting at the rear of the engine, and, except for the oil-feed pipe from the tank and the return pipe to the tank, there are no other external oil connections. The oil is forced by the pump along a gallery pipe running through the walls of the crank case and feeds the main bearings through passages in the supporting webs. The crank case itself is of new design, with a very strong nose end which carries a special oil seal on the crankshaft for slinging the engine. Following usual "Cirrus" practice, the timing-gear cover is a simple one and does not disturb any gears when removed. The cylinders are of composite construction, with steel barrels and light-metal detachable heads. The cylinder barrels are machined all over from high-grade steel forgings, made by G. Turton Platts and Co., and are located on the crank case by spigots and held down by long bolts which also secure the cylinder heads. The latter are manufactured of Hiduminium alloy and are based upon the type of head used so successfully on the '' Hermes IV A" engine. The fins are of large dimensions to give ample cooling area. A gas-tight joint is obtained by Dermatine laminated copper washers. Pistons of the full skirt type are used. They are manu factured by the Birmingham Aluminium Castings Co. from heat-treated " Y" alloy, and each carries four Wellworthy piston rings, two compression and two scraper rings. The Three views of the "Cirrus Major " : The small frontal area is well shown in the front view, while the three-quarter front and three-quarter rear views show the exhaust side of the engine. Hooks are provided gudgeon pin is of the fully floating type, located by a circlip at each end. Hiduminium forgings of large section are used for the connecting rods. They are fitted with white metal-lined steel shells, which are ground to ensure a perfect fit in the big ends. The main crank case, as already mentioned, is of very clean design ; it is an aluminium casting manu factured by the Birmingham Alu minium Castings Co., who also supplies the crank case cover, which is a shallow Elektron cast ing, with a breather cast integrally at the rear end. All gears are carried in the crank case, and are not disturbed when the timing cover is removed. A high-quality Laystall steel forging is used for the crankshaft, which is carried in five Glacier die-cast bearings located in sub stantial main bearing caps. A Hoffmann journal ball bearing is fitted at the front end to take care of the airscrew thrust. The crankshaft has a " foreshortened " nose end, which permits of a new design of airscrew boss to facilitate the removal of the airscrew. A dog is fitted at the rear end for starting. The camshaft, by the Weyburn Engineering Co., is driven by a simple train of spur gears and is carried in five bronze bearings fitted in the crank case. The rear end has a tongue for any auxiliary drive which may be required, such as for oil pumps, etc. Valves made of Kayser Ellison K.E.965 steel are used, the inlet and exhaust valves being indentical and inter changeable, and fitted with concentric coil springs made by George Salter and Co., Ltd. A hardened tip is fitted to the end of the stem and is replaceable. The valves are operated from the camshaft by one-piece cup-ended tappets (which pass through phosphor-bronze guides) and ball-ended push rods. The push rods are located in an easily adjustable cup in the end of the rocker arms, while renewable hardened pads are fitted at the other
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
