SPARK PLUGS

Ashburton Guardian, Volume 59, Issue 46, 3 December 1938, Page 5

SPARK PLUGS

TIME DETERIORATES. REPLACEMENT ADVISABLE. Tbe best spark plugs will deteriorate and wear in time, so it is advisable to instal a new set at intervals of 12 to 15 thousand miles, even though they are doing their job apparently satisfactorily. Impartial tests have demonstrated appreciable gains in economy and power, and starting is facilitated due to the better conductivity of now electrode metal. Take care to replace with the correct type of plug for youi particular engine, fit new copper asbestos gaskets if required, and set the gaps to tbe makers’ recommended clearance, using a feeler gauge far accuracy. Never attempt to adjust a spark plug by bonding tbe central electrode ; the result will be a cracked porcelain or insulator. Always adjust by opening or closing the outer or shell electrode or electrodes. Occasional removal of the plugs, thorough cleaning of carbon, and resetting of gap is productive of better than average performance. The condition of spark plugs and points gives valuable information regarding the internal condition of the.engine. They are an excellent guide to carburation and lubrication efficiency. Correct carburation causes the points and porcelains to assume a light brown appearance without soot. Deposits of soot indicate overrichness, while a weak mixture produces a white parched effect. Excessive oil on the plugs and rapid formation of oil-wet carbon result when wear or gumming of the piston rings. takes

place. Worn bearings, heavy oil, excessive oil pressure, or other internal engine wear are additional causes.

“THINKING BOX.” NEW TRAFFIC CONTROL. A traffic control box that can almost think is a recent development in London traffic control. Jt is installed in Picadilly Circus where six busy arteries converge. The function of the new device is to measure the density of the traffic, not by counting the number of vehicles passing, but by measuring the length of tbe gaps between vehicles. Three of the mechanical traffic spies have been installed. When the gaps between vehides are too long, a signal passes automatically to the spy which promptly cuts down, the green time at that point. If traffic is very heavy at another place, thie spy is iufoymed and allots additional time to it, automatically making adjustments at every other control point iu the system. By this means it is hoped to* provide a continuous flow ot traffic through the Circus and its feeders.

ROAD SAFETY SLOGAN. If you care for your family take care of your life.

SAFETY FIRST. FRESHLY SEALED ROADS. “This is the time of the year when the roading authorities find it best to carry out tar and sealing work on the road's, and a little helpful advice is given to motorists iu- their attitude towards roads freshly tarred or seal ed,” says the Automobile Association, Canterbury, in its latest safety message. “From time to tune motorists complain about trouble through freshlytarred roads, and on the other hand roading authorities complain of the thoughtless action of many motorists in the unreasonable use of recentlysealed sections of road.

“Jf speed in excess of ten. miles an hour is used the motorist runs the risk of causing himself expense and inconvenience through the tar being cast on to the bodywork, wheels, tyres, and undercarriage of the car. 'Most careful drivers move very slowly over newly-tarred surfaces and thus take every precaution against damage to paintwork, etc. Others, again, scarcely slacken speed, with results which they have cause to complain about though: the complaint is based entirely on faults of their own. “If motorists are thoughtless enough to be unreasonable in the treatment of their own cars they should think of others whose cars they may spray with particles as they pass. •‘But the roading authorities are concerned with the damage which the careless motorist particularly the dialer of the heavy vehicle, does to the road surface before* it lias time to become set and firm. The road makers are striving to give the very best surface possible for the use of motor vehicles, and the drivers of vehicles can make a vorv good gesture of self-help by travelling slowlv over tarred sections. Better advice,'still, is to make a detour if one is available even if the mileage is creator. It pays to avoid a known trouble. Tarring must, he done. Avoid it when you can; otherwise travel very slowlv.”