The Perfect Circle Piston Ring.

pISTON rings are small components which have a highly-important function, and especially in a highspeed high-compression sports or racing engine their influence can make all the difference between a first class and mediocre performance.

The Perfect Circle ring, which is of American design and manufacture is particularly suitable for high-efficiency engines, and indeed since its introduction in Europe it has been adopted on a large number of racing cars, including Sir Malcolm Campbell's Mercedes and Carraciola's racers.

Perfect Circle rings are made in two types—compression and oil regulating. Outwardly the former does not differ from other standard patterns, but the material used, and the process of manufacture give them exceptional qualities in holding compression, long wear and freedom from edge warp. The oil regulating ring has specially designed slots and grooves in its vertical face, and this feature has the effect of concentrating the ring's tension at the two extreme edges of the face, thus holding these surfaces in firm contact with the cylinder bore walls. The channels collect oil and distribute it around the whole circumference of the ring and make for oil economy and efficient cylinder lubrication. These rings can be obtained from the Perfect Circle Co., Ltd., 10, Store Street, London, W.C.1.

Special Exhaust Systems.

Obviating loss of power through back pressure while at the same time keeping the engine reasonably silent is not too easily carried out by the amateur, and for this reason there is a considerable market for special exhaust systems which enhance a sports car's running and yet make it unobtrusive on the road..

The Sykes silencer and exhaust system is made for attachment to popular standard production cars and it can be fitted with very little trouble. It is of straightforward design and is available in different sizes to suit cars of various li.p. The prices range from E2 to £2 15s. Makers' address : Sykes' Silent Exhaust, Ltd., 12, Cross Jerry Street, Leeds.

Another concern who market an attractive exhaust set is Cheswick and Wright, of Gladstone Street, Blackpool. This is supplied with all necessary clips, hangers, etc., for attachment to Austin Seven, Morris and other popular makes. The price is 50s. complete.

Special Steering Wheels.

The steering wheels fitted as standard to a good number of cars do not always suit the individual taste of the owner, and for these the products of various accessory makers are of interest. Bluemel Brothers, Ltd., have for many years made a varied range of steering wheels, and their latest spring spoked model is already extremely popular. There is no doubt that these special wheels make long spells of fast driving far less fatiguing, and at the same time their excellent finish enhances the general appearance of one's vehicle.

Another steering wheel produced specially for sports and racing cars is the " Brooklands " made by F. Ashby and Sons, Ltd., of Stirchley, Birmingham. This wheel is unique in that the rim itself is flexible, as well as the spokes, and the former is covered with a special rubber coating which is impervious to petrol, oil, etc., and is guaranteed not to split or crack. It is sold in two sizes-16 inch from 36s., and 18 inch from £2. Messrs. Ashby also make stone guards, ribbed brake drums, mudguard grilles and other fittings and parts of interest to the sports enthusiast.

For Hotted-Up " Hornet i."

The popular Wolseley Hornet is admirably suited for modification for sporting purposes, and the owner who is anxious to do so will have no difficulty in finding firms who specialise in the supply of modified parts and accessories which will increasethe standard " Hornet's" performance. With a small " six" correct gas distribution is of paramount importance, and, when well-designed, a twin carburettor arrangement will add greatly to the pep,' flexibility and other qualities for which the sporting driver looks. The

firm of V. W. Derrington market such an induction system, which incorporates two S.U. downdraught carburettors attached to a special manifold with polished internal surfaces. The manifold has a very hot "impact hot spot" so that only a very dry mixture is used, and drain pipes are fitted so as to prevent the cylinders from being flooded with petrol should the carburettors ever leak or seep. The exhaust branches of the manifold are of large diameter to reduce gas restriction. The price of this fitting is 415 10s. Maker's address :-159, London Road, Kingston-on-Thames.

For " Oily " Engines. Oiling up troubles are not infrequent on sports engines especially after lengthy service, and the F.E.W. Plug Adaptor has been designed to overcome this difficulty. This device consists of a suitably threaded holder into which the plug is screwed and the whole is then screwed into the usual plug orifice in the cylinder. Thus, the plug points and centre electrode are masked, and it is impossible for any surplus oil which may have got into the combustion chamber to reach them. It might be assumed that the use of this adaptor would interfere with the combustion of the gases, but in actual practice, according to the makers, such is rot the case. On a high-speed engine, however, it is necessary to slightly advance the ignition setting owing to the slight ignition "time lag" which occurs. The price of the P.E.W. Adaptor is 10s. for a set of four, or 15s. for a set of six. The manufacturers are Amalgamated Accessories, Ltd., of 7, Tavistock Place, Russell Square, Londor, W.C.1

Checking the Battery. Stadium, Ltd., the well-known manufacturers of accessories have recently introduced a useful additional fitting for the lighting and starting equipment of a car. This is a small meter suitably graduated to indicate the condition of the battery, and it shows at a glance whether it is fully charged, overcharged, or not charged enough. No special wiring is

required and it is made to plug into the ustul inspection lamp sockets to be found on the switch board. The price of this indicator, which ftinctions accurately and is obviously a useful gadget, is 12s. 6d.

Protecting the Radiator. Stone guards are becoming increasingly popular, for besides serving the very useful purpose of protecting the somewhat vulnerable part of the radiator, they improve the appearance of a car. The B.S.S. stoneguard is made in different forms to suit sundry makes, such as the Austin Seven, Morris Minor, Wolseley " Hornet " and Rover. Made

of solid brass it is smartly finished in chromium plate, and the price ranges from 21 7s. 6d. to 21 15s. 6d. Makers' address :—B.S.S./Manufacturing Co., 55,

Kew Bridge Road, Brentford Middlesex.

A Cleaning Aid. A new and useful device has lately been placed on the market by the firm of Herbert Terry and Sons, Ltd., of Redditch, which aids considerably in the work of cleaning a car. It consists of two parallel spring-steel blades so kformed that they will grip firmly a swab, sponge, duster, etc., and by using it, the cleaning of

awkwardly-placed parts becomes a simple and easy process. Knowu as the " Avecta " cleaning tongs it can obtained for 2s. 6d.