Vintage Mustang Forums banner

Spark plug gap

1K views 6 replies 4 participants last post by  Guest 
The whole reason for wide spark plug gaps was to have a longer burn-time with lean fuel mixtures so all of the fuel mixture would be burned. Carbon molecules are farther apart in a lean fuel mixture and with a weaker coil the spark tends to die out causing a lean misfire. So starting in the 70s cars started having a higher coil output with wider spark plug gaps with leaner carbs to prevent lean midfires which would result in higher hydrocarbons.

So with a car like yours a wider gap really isn't needed. A gap .040 is probably a good place to start.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top