You’ve got questions. We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we’re examining a double ignition setup.
Q: I have a V8 engine with a single ignition system. For reliability concerns, a dual ignition system is needed. With single spark plugs per cylinder, is there any way a “backup” ignition system could be installed?
A: For long duration races, such as circle track competition, MSD offers an automatic coil selector which allows you to run a backup ignition on carbureted, pre-computer V8s. This provides added peace of mind in case of ignition/ignition coil failure and would address your reliability concerns.
The MSD Automatic Coil Selector allows you to quickly switch from one MSD system to another from inside your vehicle by just flicking a switch. With the coil selector, you will run two coils and two MSD ignition boxes; the coils and boxes are connected to a single-pole, double-throw toggle switch. The coil selector has two posts that are connected to the voltage towers of the coils, while the third post is connected to the distributor. When you switch to the backup ignition using the toggle switch, the coil selector automatically switches to the backup coil and then transfers that coil’s voltage to the distributor cap. Although you are still running only one distributor, distributor failures are rare.
Although double ignition setups are common for racing, you could easily apply this configuration to bring added reliability to street applications, too. For this scenario, we’d recommend MSD 6A ignition boxes and MSD Blaster 2 ignition coils.