Most automotive ignition coils, from purely stock to full-on racing units, are rated at between 4 and 10 thousandths of a Henry, called 4 to 10 milliHenrys ( abbreviated 4mH).

Flame Thrower II coils have lower resistance, 0.6 ohms for use with Ignitor II ignition systems as well as many other high-energy ignitions. The low resistance helps to produce up to 45,000 V.

Spark plugs and ignition coils have become life-of-the-engine components, though it is best they be replaced every 50,000-100,000 miles. 0:00 / 0:00. Chevrolet’s High Energy Ignition ...

How do you do ignition coil service if the coils are either stuck on the plug or the connector will not release?

Q: Last month we described how to remove a first-generation (’74-’80) High Energy Ignition (HEI) distributor from your Corvette, disassemble it, test its indivi ...