The Last Little Drop
Although it is well known that “saved-up basic” is the most economical of fuels, eventually we got down to our last little drop. So, in an Austin Seven with over 70,000 miles run, and 31,000 completed since the last de-coke, we went off on the last of those harmless, carefree trips of exploration which we and countless thousands of enthusiasts so enjoy, but which are now denied us. In the rawness of the last Saturday in November we went via Twyford and Henley, turning off at the foot of Nettlebed Hill to climb gently up and over the Chilterns. Rain fell from lowering skies, and nothing of particular interest was encountered, save for one of Burrell’s Compound Engines in a field just beyond a lane leading to Bix Bottom.
We fell to wondering why some people cannot help enjoying motoring, even in dull conveyances on not especially exciting occasions. A friend of ours once said it is because one anticipates adventure round every corner, but our present companion preferred the theory that it is because one is sitting down, “and it is so nice to sit down anyway.” Be that as it may, we pressed on happily and eventually came to our objective - an outhouse containing an early aeroplane engine.
There this remarkable discovery stood, a small 3-cylinder air-cooled rotary, with rotary valves. To our surprise both valves and pistons were free and the engine turned-over easily. In the dim light we discerned a single valve running laterally across each detachable finned head, each one driven by a bicycle chain from a separate sprocket at the rear of the crankcase, these three sprockets being driven, in turn, by pinions engaging a toothed ring on the crankshaft. Of the later V-twin G.N. engines, John Bolster once said he preferred the “Vitesse” with its chain-driven o.h. camshafts to the “Akela” because “it was such fun seeing all that machinery going round.” What, then, would he say to this engine, with three external chain-drives, which itself revolves? There was a large rectangular exhaust port in each head and a scoop appearing to direct air into the hollow spindle of the rotary valve. From each inlet port a pipe led vertically downwards behind its cylinder into the crankcase into which the carburetter presumably fed, while up the front of each cylinder a pipe carried oil to the valve. A propeller boss was attached to the front of the crankshaft and the alloy engine mountings were in place. The plugs appeared to screw into adaptors protruding from the side of the heads. The cylinders were integral with the crankcase, which thus bolted up in three sections.
That then was what we had set out to discover. No information was forthcoming about the engine except that it was made, probably as a one-off job, just before the Kaiser War, by a firm that also manufactured a few motorcycles and then closed down. We have consulted “The History of British Aviation” and Inman-Hunter’s “Rotary Valve Engines,” but can find no mention of it. Obviously, we had discovered a rare type, and we imagine the combination of rotary valve and rotary engine must be unique.
Although it was dark and raining hard when we arrived home, the afternoon had proved just as satisfying to us as, no doubt, had football, cinema and dog racing to other people. Why on earth we cannot continue our particular brand of amusement even in curtailed form, while other varieties are to continue virtually unmolested, we just cannot comprehend. Anyway, all pleasure of this sort is now over, even those occasional journeys between office and home which delighted us by taking in, in a mere 40 miles, not only the City of London but four counties in addition. - W. B.