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AC Delco spark plug question
- Thread starter Chevelle3221
- Start date
X means wider gap for electronic ignition. You could re-gap within reason. Colder is not what you want, they will foul worse.
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Well I do have an MSD set up. So I guess the X makes sense but still don't understand the difference
X is for high-energy ignition (H.E.I.) used in all GM vehicles in North America circa 1975–1986, which uses a higher spark-plug voltage, which is caused by a wider spark-plug gap. The spark-plug voltage increases with the spark-plug gap, as the electrical-breakdown voltage of the air increases with the separation of the electrodes.
High energy ignition - Wikipedia
- Joined
- Nov 23, 2021
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So I guess the X plug would work with the MSD 85551 ignition systemX is for high-energy ignition (H.E.I.) used in all GM vehicles in the US circa 1975–1986, which uses a higher spark-plug voltage, which is caused by a wider spark-plug gap. The spark-plug voltage increases with the spark-plug gap, as the electrical-breakdown voltage of the air increases with the separation of the electrodes.
High energy ignition - Wikipedia
en.wikipedia.org
Check with MSD for the appropriate spark-plug gap for your application. Click on the Ignition tab at the link below.
Resources - Holley
www.holley.com
The difference is the "out of the box" gap of the R45TSX is about .010" wider than the R45TS.
YT videos about spark plug gaps:
^^This
