Sporting Cars on the Road

Sporting Cars

on he Road

THE EDITOR

THE SUPERCHARGED SPORTS LEA -FRANCIS.

FiVER since Kaye Don’s victory on a Lea-Francis in the Ulster Tourist Trophy race of 1928, this model has enjoyed a steady run of successes. Owing to the foresight of the manufacturers in marketing the supercharged model as standard as soon as it had showed its mettle, it has proved a very popular car with the amateur who requires something for serious competitions, which at the same time can be used for ordinary work on the road. A measure of this popularity is to be found in the large number of these cars on the roads to-day, which gives ample answer to those over-conservative motorists who still maintain that a supercharged car is not suitable for the private owner. In the case of the Lea-Francis the supercharger is a .. , Cozette, situated in front of the cylinder block and drawing its mixture through a carburettor of the same make. This instru

ment, as most of our readers will remember, consists of an eccentric with sliding vanes which make contact with the periphery of the casing. These blades

are lubricated by mixing oil with the petrol, and this is a very simple matter as a neat measure is incorporated with the filler cap ; one of these filled with Castrol XL. must be put in to every two gallons of fuel. The bearings of the supercharger are lubricated by a mechanical pump, which draws its supply from a neat tank on the front of the dash, and on the same side as the sump filler cap. A two-way tap system is incorporated so that for prolonged “blinding,” they may be turned so that oil is supplied to the supercharger by the main pressure system which feeds the engine bearings. The engine is a perfectly normal 1500 c.c. 4-cylinder O.H.V. job of 69 mm. bore by 100 mm. stroke, and therefore at ordinary touring speeds on a small throttle opening is very smooth, and shows the advantage of using forced induction to get the extra speed _ when required.”‘ The actual car which we took over for some days, for test, was a demonstration model which had rcovered many thousands of miles at high speeds, and was therefore expected to show some signs of its past life. How ever, it appeared to have stood up remarkably well, and the only sign of a hard time was given by the fact that the petrol and oil consumptions were somewhat higher than would be the

case on a newer engine, and merely showed that new piston rings would shortly be required.

The engine and supercharger were mechanically quiet, and at normal speeds we were entirely able to forget the presence of the latter. When we took over the car it was fitted with some comparatively ” soft” plugs, and we soon found that our normal method of progression from place to place, i.e., with the throttle well open, did not agree with them, and produced

pre-ignition. This caused us a little bother at first, till we found others of suitable type.

The acceleration was very good, and on second gear 10-30 m.p.h. takes 4 seconds, and 10-40 m.p.h. 6 seconds only, The maximum speed on this gear is 45-50 m.p.h. Third gear, which is naturally in fairly constant use when driving hard, gave us a maximum of 70 m.p.h.

The maximum speed achieved during our test, with four people aboard was 82 m.p.h., but owing to the business of plugs, just referred to, it was not considered

advisable to keep the throttle too far open too long, and there is little doubt that this speed could be improved on. Even so it is extremely good. The correct plugs for fast work in this engine are K.L.G. 396, which is a road racing type. The gear change is light, but requires a little practice at getting the revs just right, before perfectly silent changes can be guaranteed, but we became quite at home with this gear box in a few hundred miles, and naturally any owner of one of these cars will be

cars so used to it, that it will never strike him as presenting any difficulty.

The steering and cornering are good, but it is very important to see that the tyre pressures are correctly adjusted to the load, as the steering is somewhat sensitive to this point. Personally, we should have preferred slightly more caster action, but it is impossible to please everyone in the matter of steering.

As can be seen from the illustrations, the chassis is very low, and stability is excellent, and as we were often in a considerable hurry, this was well tested.

The vacuum servo brakes are very powerful and light to operate, and will bring the car to rest from 40 m.p.h. in 65 ft. Adjustment is by independent wing nuts to each brake, as this firm in common with many others, hold that this is the only way to secure even braking, and also even wear on the linings. The only alternative is a very elaborate system of compensation using differentials, similar to that used on one very large and costly car to-day, but which is too cumbersome to be used on a 1/-litre car.

Altogether the supercharged Lea-Francis is a car for the man who wants something with a performance out of the ordinary which will also be thoroughly suitable for general use, and at 2495 it presents excellent value.