FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1932
1932 - 0624.PDF
FLIGHT, JUNE 24, 1932 The Napier E.Q7 Aero Engine •" Jlr-^HE tendency in modern air- \^) II craft design is ever to- III wards greater aerodynamic efficiency. Hitherto this tendency has been particularly noticeable in high-performance mili tary aircraft, but in commercial types also the demand for low drag is becoming more and more insistent, and the smaller types of aeroplanes, designed more particularly for the private owner, are gradually coming to share in the modern search for efficiency. The in-line, or " straight," cylin der arrangement does give a small frontal area, and consequently a low air resistance. The time was when it was feared that the effective cool ing of all the cylinders might present serious problems, but practice extending over several years, and covering hundreds of thousands of flying hours, has shown that the cooling problem is by no means insuperable. It is true that so far our experience has been mostly with " straight- four " engines, but " straight-sixes " have been built, and A STRAIGHT-SIX AIR-COOLED INVERTED ENGINE Bore, 44 in. (I 14 mm.). Stroke, 5J in. (133 mm.). Compression Ratio, 5-3 to I. Normal Speed, 2,000 r.p.m. Normal Power, 150 b.h.p. Maximum Speed, 2,300 r.p.m. Maximum Power, 170 b.h.p. Weight, 410 lb. (186 kg.). Specific Weight (Normal) 2-73 lb./hp although perhaps slightly more diffi cult to cool, the difficulties are not great enough to be really serious. Yet another tendency in modern aeroplane design is towards better view for the pilot. As more and more aircraft come into general use, the need for a good view in all direc tions which matter will become more and more vital. The inverted in-line engine is particularly helpful in this respect, since the airscrew height above the ground can be attained without a tall projecting area right in front of the pilot's eyes. The flat top of the crankcase of the inverted in-line engine offers no obstruction to the view, and as the hanging cylin ders are narrow in the region of the cylinder head, the pilot can, by leaning out slightly, see diagonally forward and downward past the engine. Considerations such as those outlined above influenced the directors of D. Napier & Sons, Ltd., in deciding that the first Napier low-power aero engine should be of the inverted in-line type And the E.97 engine illustrated THE NEW NAPIER E.97 AERO ENGINE : These four views give a good idea of the very clean exterior of the engine. ^ All auxiliary drives are concentrated on the rear end of the engine. Three hooks are provided for slinging, two at the rear corners of the crankcase and one on the front end. (FLIGHT Photos) 576
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
