Archive for the 'engines' Category

The Verdik Petrol Economiser

I invented this during one of the many cross-country flights with pupils which were part of my duties as an EFTS instructor. With the pupil doing most (or all) of the actual flying my mind had plenty of time to wander. In those days all cars had carburettors metering the petrol/air supply to the engine and the petrol jet would start to wear and so let through more petrol than the ideal 14/1 air/petrol mixture. One could buy an extra air control for £1 or so. This was only a rubber tube from the engine inlet manifold between the carburettor and engine and a tap fixed to the dashboard. As soon as the engine had warmed up one opened this tap just enough to improve the engine performance. The trouble with this method was that the tap must be closed every time one came to rest (traffic lights etc) or the engine would stop running. How to achieve this automatically? The answer came to me on one of these flights during which I was asking myself “What happens at tick-over that is different when the engine is running at 10 mph or more/” The answer is “the battery is being charged”. So a solenoid can do the work of opening and closing the extra air tube. Thus the Verdik Economiser came into life. It was given a good report by “The Motor” whose chief engineer was Laurence Pomeroy with whom I became friendly, and it was sold by a number of garages, Boon and Porter amongst them. But I never made any money out of it. I have no flair whatsoever for marketing anything. In any case carburettors were soon becoming out of date and alternators were replacing dynamos.