some anzani gen

SOME ANZANI ” GEN.”

We have been loaned, by Cur. B. W. Pollard, a catalogue issued by the British Anzani Engineering Co., Ltd., in about 1928. Some interesting data relating to the famous 11-litre s.v. Anzani engine appears therein. This engine was made in touring, sports tourer, super sports, high-efficiency and racing versions. Although the light weight of this engine is emphasised, the estimate of 160 lb. made by Cecil Clutton and other writers of recent times would appear to be optimistic, as the makers claimed 166 lb. less carburetter, magneto, flywheel and exhaust manifold. The Super Sports engine differed in respect of a head specially finished internally and giving a higher compression ratio, cleaned-up ports, in creased valve overlap, stronger valve springs and special valves. It was claimed to give 47 b.h.p. at 4,000 r.p.m. The H.E. or High-Efficiency model had a special head, polished porting, highoverlap camshaft, balanced pistons lightened by the employment of three narrow rings, ” Aero ” valve springs and connecting rods of heat-treated 100-ton nickel-chrome steel with the gudgeonpins running directly in the rods to further reduce weight. This engine gave 52 b.h.p. at 4,500 r.p.m. The Racing engine had a built-up, roller big-end crankshaft running

in massive journals, and used very largediameter gudgeon-pins. Pump cooling was used, and blown with a Cozette supercharger the output was 110 b.h.p. at 5,500 r.p.m. This engine was, of course, used by R. G. J. Nash in his famous Frazer-Nash “The Terror.” The foregoing indicates why merely taking an Anzani engine from an early A.C. or similar small car and putting it into a G.N. or Frazer-Nash doesn’t instantly result in racing-car performance.

Other interesting engines described in this catalogue were the 1,100-c.c. aeroengine, giving 34 b.h.p. at 3,000 r.p.m., and the 57° Special 4-port 1,100-e.c. V-twin engine designed to propel a solo motorcycle at over 100 m.p.h.