Classic Car Ignition Systems

Upgraded Ford Ignition System. Photo by Mark Gittelman

When classic car owners find it necessary to perform repairs on their vintage automobiles they're often faced with tough decisions on how to proceed. As an example, should they replace the failed points and condenser or upgrade to a distributor that utilizes an electronic ignition?

Here we’ll discuss maintaining the original integrity of the engine compartment while taking advantage of replacement parts that increase reliability.

The focus will be on an automotive system that has even the most diehard preservationists reaching for modern components. Owners have a choice, they can upgrade classic car ignition systems with flashy parts and embrace the modern look or they can seek out ones that look old on the outside, but contain the latest technology on the inside.

The Primary Ignition System

If you own a classic car with the original ignition system you've probably been faced with a no start condition at some point. For those that prefer to drive their vintage automobile to the local car show this can ruin a nice day. Since the spark that starts the engine originates from the primary ignition circuit, we'll talk about this system first.

The primary ignition system consists of the battery, ignition switch, coil and the components contained inside the distributor. The coil takes battery voltage and turns it into high-voltage surges sent to the distributor.

Although the basic principles of ignition coil operation have remained the same over the last 100 years, improved manufacturing capabilities have made them more reliable.

As an example, in the old days, they insulated coils by placing the internal windings in an oil bath. Now the primary and secondary windings inside of a coil are insulated by chemical resins.

These advanced polymer resins provide superior insulation and won't leak out like the oil bath coils of the past. The good news is you can find replacement coils that look identical to the original parts on the outside yet contain the modern technology inside.

Electronic Ignition Upgrade for Classic Cars

There are a lot of diehard fans of the breaker point ignition system. Those that own a dwell meter and have become experts at replacing the points or enjoy making the adjustments every 3000 miles can skip this section. However, for those classic car owners that wish to modernize their automobile, simple electronic ignition upgrade kits are available for most distributors for around sixty dollars. Let me explain why you might want to perform this upgrade and provide details about what's involved.

Car manufacturers used breaker point ignition for more than 60 years. Cadillac started using it in 1910 and they phased the system out in the early 1970s. It's a two-piece component that requires frequent maintenance and adjustment to keep them working properly. The distance between the two contact points is known as the air gap. The high-voltage spark that travels across the two contact points will eventually increase the gap.

When this air space becomes too large the automobile performs poorly. Eventually the spark will not make it to the spark plugs and cause a no start condition.

An ingenious way of replacing the breaker points and condenser with modern electronic ignition has been around for a while. The nice part is, this alteration leaves the current distributor in place and the upgrade cannot be seen without removing the distributor cap. First you install a magnetic pole module on the base plate of the distributor using the hold down screw from the points. An included magnetic ring is then pushed onto the distributor shaft. Next, the positive and negative wires from the magnetic module are connected to the proper coil terminals. Finally, you set the gap using the provided plastic feeler gauge. And that's it, you're now converted to modern electronic ignition.

Secondary Ignition System Upgrades

The secondary ignition system includes all of the parts from the distributor cap to the spark plugs. These are components associated with the delivery of the spark to the cylinder at the proper time. A common upgrade that classic muscle car owners like to perform is to replace the factory issued 6 mm or 7 mm spark plug wires with high performance ones that are 8 mm in thickness or larger. The increased thickness allows for a larger core and thicker insulation to protect the spark from outside influences.

I'm personally against this upgrade unless you already installed high-voltage performance parts upstream. Things like an Accel Super Coil or a MSD high-voltage ignition module designed to provide a hotter spark at the plugs can benefit from thicker plug wires. The thickness of the factory wires is sufficient when the original ignition coil, breaker points or the standard electronic ignition is in place. Since the spark plug wires are highly visible using bright yellow or fluorescent orange performance wires can detract from the beauty of an original engine compartment.