[Toy4Chris]

I recently purchased a new set of plugs for my car. Suspected that the previous set (only 3months old) was bad, as the car ran very poorly. I had asked at the retail store (Auto Zone) the proper gap, which they said was .044. After installing the new plugs, and seeing that the car ran much better, I noticed under the hood that the gap was to be set at .054
My question is what needs to be done here? Should I take them out again and re-adjust the gaps from .044 to .054 or leave them alone? What would be downfall of having a gap approx 20% smaller than what the manufacturer suggests.
THANKS FOR THE HELP

[mzbk2l]

What ignition do you have? Original points? HEI? MSD?

[Toy4Chris]

This problem I'm having is with a 93 Ford Econoline E150 v8 van. Sorry for not giving those details. HEI

[Billy177]

if they are easy i would regap them if not then i would just leave them. it will not do any harm leaving them at .45

[Toy4Chris]

6 plugs are pretty easy...the other 2 are HARD!!!!
Will it run any smoother with the correct gap? What will a smaller gap do different than if it were set correctly???

[Billy177]

maby a tiny bit worse gas milage but that is all

[Toy4Chris]

Just for my own knowledge...what will happen if the gap is larger than spec?
Smaller than spec?
Besides what what already mentioned.....perhaps slightly less fuel economy, will the motor run the same whether larger gap, normal gap, or smaller gap?
Just curious.
With the price of gas headed to $3 soon, I can use any fuel savings where possible.
WHY IS GAS HEADING TO $3 AGAIN??? I just love Mr. Bush...don't you???

[Half-Inch Stud]

Large gaps will suppress the spark-ignition effect at peak torque. Only benefit is prolonged electrode life. I think the MFGrs made a big mistake on .080" gaps

So, for best Mileage, power, go for the small gaps like .040 to .045.
Only drawback is quickened EDM"d electrode wear.

.020-gaps too small, probably show poor flamefront repeatability. 035 gaps maybe the threshold into success.

[Geoff]

If it runs better with a larger gap, leave them there. The ignition system [ leads, insulation ] etc is obviously in good condition because the bigger gap needs a higher arcing voltage to fire the gap. If the system was in poor condition, you would get misfires etc. Instead, you found the car ran better.
The only downside is that the gaps will need to be checked & reset more often. You don't want the gaps to erode too much, to the point you get misfires.
0.054" is not that large for a medium compression, normally aspirated engine. GM recommended 0.060" gaps for the HEI when it was introduced.