This blog, in addition to the usual maintenance details for classic mini cars, an attempt is made to explain the "whys" and "wherefores" of the various jobs.

Thursday, 15 October 2009

Spark intensives

Many so-called spark intensifiers consist, in fact, of nothing more than an auxiliary spark gap—two wood screws in a plastic housing—that is intended to be fitted in the main high-tension lead between the ignition coil and the distributor. Often the cost is out of all proportion to the real value of the device. Moreover the high voltage that is continuously imposed on the ignition system by the permanent spark gap may cause a breakdown in the insulation at some point.
The Norton ignition converter is, however, a notable exception to the general rule. This device, which is obtainable from Scrutton and Co., 97 Wanstead Park Road, Ilford, Essex, operates on an entirely different principle: it converts the normal ignition current into a high-frequency oscillating discharge. Now, a high-frequency current has some unusual characteristics. For example it treats an oiled-up plug insulator, or one that On terms of ordinary high-tension current) is short-circuited by con-densed moisture, as a far more formidable barrier than the air gap between the plug points! It is not surprising, therefore, that the Norton converter confers virtual immunity against difficult starting or misfiring caused by oiled-up plugs or condensation. Even under more normal conditions, the more effective spark usually results in smoother and more regular idling, better pulling and some improvement in fuel consumption.