Workshop Basics

A cheap, simple and highly advantageous classic upgrade

If it ain’t broke, don’t fix it,’ is an excellent mantra for the classic car enthusiast. It dodges the all-too-common trap of spending money on making things worse. However, we’d make an exception when it comes to electronic ignition. It’s simple, easy to fit and brings nothing but advantages.

The ignition system produces a spark when the current to the coil is turned off. The more sharply it stops, the bigger the spark produced. In a conventional points system, the cut-off tends to be a bit ragged due to a bit of current jumping the gap as points start to open. The condenser tries to minimise this, but it isn’t wholly effective.

An electronic system has a magnetic or optical pickup (the trigger) and turns off the current using a transistor (the amplifier). There’s no gap-jumping and the on-off phase is in the order of microseconds.

The improved precision of operation results in a spark that’s more accuratelytimed and consistently powerful under all conditions. This improves smoothness, low-speed torque and high-speed power to some extent. The sometimes-troublesome condenser’s done away with and since wear of the points’ heel and contacts are eliminated, the system never need be adjusted after it’s initially set up.

Traditional electronic ignition systems consist of a trigger unit in the distributor and an external amplifier. In recent times, though, compact systems that combine the trigger and amplifier in a small unit fitted in place of the points have become popular – and rightly so. They’re cheap, quick to fit and completely hidden when the distributor cap’s refitted. They’re available off-the-shelf for almost all common distributors.

If you’re fitting a kit because of poor ignition performance, check function and cleanliness of the rest of the system (high and low tension wiring; coil; ignition switch). It won’t magically fix extraneous defects.