ACCESSORIES a FITTINGS
Page 19
If you've noticed an error in this article please click here to report it so we can fix it.
for Light Vans.
Lodge Plugs.
The 1917 Lodge catalogue of sparking plugs should be m the hands of every user. Its ostensible purpose is to enable him to choose that plug best adapted to the special requirements of his vehicle. Incidentally, a perusal of its pages will acquaint the reader with many of the whys and wherefores of plug construction.
The Lodge Co. markets 20 different types of plugs. In such a simple detail as a sparking plug, it would seem impossible that a need for so many different types should exist ; as a matter of fact, experience has shown that no one plug suits all kinds of engines. Special types have to be designed to suit the peculiarities of various power units.
Steatite or Mica insulation.
The dividing line between the two main classes of sparking plugs is the type of insulation adapted, whether it be steatite or mica. On certain high-speed, high-oompression engines, the temperature is so high that steatite insulators are
liable to crack. In such cases, mica-insulated plugs are needed. As a matter of fact, there are very few commercial users whe.will need to consider purchasing this type of plug. A common cause of trouble with sparking plugs is due to overoiling and the consequent sooting of the plug. For this reason steatite insulators are, as a rule, best. In the great majority of cases, particularly in commercial vehicles, the standard type of plug, such as we illustrate on this page, will be the me to use. In the alternative, the slightly more expensive one, which embodies a weather-proof terminal, in the case of machines which have to stand all weathers, will prove to be worth the additional outlay.
Special Forms of Plug.
There are certain special forms of this same type of plug which have been made to meet the constructional peculiarities of certain engines. For example, in some the screwed hole of the valve cap is so deep that it is necessary to use a. special plug with a long reach, in order to bring the points down into the combustion chamber ; alternatively, the valve caps may have deep recesses, in wAich case, what is called the plug with a long barrel
must be used to bring the hexagon portion above the top of the cap, so that it is accessible to the ordinary spanner. On American vehicles, as a rule, a different type of plug is advisable. A perusal of the catalogue will enable the user to decide which Lodge plug is best for his machine if he is using an American vehicle. Space does not permit of our going closely into this matter here.
An important part of the little pamphlet is that dealing with the design of sparking plugs. In the Lodge, the insulator and metal parts are held peimanently together by enamel. It is claimed that the plug is absolutely gas tight under all circumstances, and that the enamel allows for the difference of expansion between these parts ; furthermore, the central pin is also welded to the insulator by the use of enamel, and this method allows of a larger pin than that usually used. In the standard plug, the triple spark gap is adopted as standard, and the points are substantial and of pure mckeL A Pneumatic Tube Saver.
Those of us who have removed a pneumatic tire tube from a wheel
after long service, and particularly if that service has been accomplish ed without there previously having been any need for the removal of this tube, will have noticed the deteriorating-effect of the contact of portions of the wheel rim on the tube. s It will very often be found that the tube has worn quite thin in places along its inner circumference, and that even if it has not been nipped between the sharp edges of the cover, it always appears that a very short time only must elapse before the tube is unfit for further service.
Leo. Swain and Co., of 237,
Deansgate, Manchester, has recently placed upon the market a simple device to overcome, this defect. It takes the form of an endless rubber band described as a "Tube Saver," which fits on the rim and acts as a buffer between the tube and wheel and obviates the difficulties to which we have alluded. It also tends to prevent in-. ternal nip and assists materially in holding the cover in its place.
It will, we are sure, come as a real economizer to users of light vans and other vehicles running on pneumatics.