DAMAGE TO PLUGS BY MISUSE OF SPANNERS

Evening Star, Issue 22443, 14 September 1936, Page 13

DAMAGE TO PLUGS BY MISUSE OF SPANNERS

When the proper plug spanner has been t mislaid, it is sometimes difficult to tighten up or remove a sparking plug, owing to the fact that there is insufficient room to use an ordinary spanner on the hexagon of the plug. It is then very tempting to use the spanner on the gland nut by which the centre portion of the plug is secured to the body, but this is_a practice which should always be avoided. The gland nut is usually so tight that if a spanner is used on it the plug can.be removed, but if pressure is applied on it irreparable damage may bo done. The gland nut may bo so distorted that it can no longer effect a gas-tight joint between the centre portion and the body of the plug. If there is the least gas leakage here, excessive overheating will result, with consequent pre-ignition and possible engine seizure. Alternatively, the insulation may be cracked, this allowing leakage of. the electrical current.' The safest plan, when the plug spanner is lost, is to leave the plugs alone until a new spanner of the right type is obtained. Ordinary, engineers’ box spanners are often so short that the tommy-bar fouls the terminal screw and bends it as soon as pressure is applied, this doing almost as much damage as distortion of the gland nut. REMOVING PISTON RINGS Removal of piston rings without distortion or breakage is a difficult matter unless care and patience are exer-' cised. A clever tool in the form of an expander is used at service stations, but the job may be done in its absence by. inserting three or four pieces of hacksaw blade (with the teeth ground off) equidistantly around the ring. They permit the rings to slide off with perfect safety.