Re: Electronic ignition

Posted by Rusty O\'Toole On 2009/8/4 16:42:28

On the subject of increasing spark plug gap with electronic ignition.

There are certain things to watch out for. Electronic ignition alone will not cover it.

You need to be aware that if you increase spark gaps you increase the chance that sparks will jump and arc where you don't want them to.

Distributor cap. Look inside the distributor cap of an electronic ignition car. Usually you will see ridges or fences. These are to help isolate the sparks. Your cap is smooth inside.

If you can find a modern cap that will fit your distributor it would be a good addition.

Another thing is the plug wires. New wires have thicker insulation usually made of silicone rubber. You may get away with your old wires but only if they are carefully isolated on insulated standoffs and do not come near anything metal. Even then you may get a cross fire or lose sparks in damp weather.

Whether you want the new fat plug wires is the question.

Your old coil can be a problem too. If the 12 volt connections are too close to the coil wire sparks can jump across. I have seen this on old cars with standard ignitions if the plug wires were shot.

So for maximum efficiency you need a new cap, wires, and coil. Then you can open up the gaps to the same as a modern car.

Failing that, I wouldn't open up the gaps more than .005. And if you really want to go uptown, buy a set of Bosch Platinum plugs. They should give you an improvement all by themselves and they last 50000 miles to boot.

This all applies to wider plug gaps ONLY. If you do not widen the plug gaps you don't need to worry. The reason is that the spark will take the path of least resistance.

In other words, if you do not increase the plug gap you do not increase the chance of sparks going the wrong way no matter how "Hot" your ignition.