Spark Plug Gaps?

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cheddarbacon said:


That's the gap for E6 heads on an '86 Mustang.

Some reference manuals incorrectly used this as the gap for all 85-93 Mustangs.

I beleive all 79-86 Mustangs use 0.044" as their gap.

In 1987 Ford upgraded the ignition and 0.054" is the new gap.
 
stock gap is .054"
i use about .045 for teh tighter spark
plus i occasionally spray...so i leave it closer

the car can actually run better at lower gaps when your ignition is tapped out

if spark is getting weak....use .040-.045
 
Mustang5L5 said:
That's the gap for E6 heads on an '86 Mustang.

Some reference manuals incorrectly used this as the gap for all 85-93 Mustangs.

I beleive all 79-86 Mustangs use 0.044" as their gap.

In 1987 Ford upgraded the ignition and 0.054" is the new gap.

'79-85 is .052-.056

I hope that u are not using 24's or 25's in those '86 heads. They take a Motorcraft extended tip AWSF or AGSF type plug, which translates to a Autolite 103,104, or 764.
 
NosPony - Only if you had a nice sparking ignition system like an aftermarket set from Crane or MSD. Mine is old and untouched besides different wires everything else is factory original or OEM replacements...my car ran better with the lower gap...
 
to augment what David brought up, there is a school of thought floating around that wider is not necessarily better (thanks to cheap dyno pulls - people test this kind of junk).
one can get better results from less gap (just like there is a point of diminishing returns with timing advance, but before detonation). Not really any reason (I see) to run on the edge of misfiring.