Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: blackcat85 on January 27, 2010, 11:31:18 PM

Title: spark plug ???
Post by: blackcat85 on January 27, 2010, 11:31:18 PM
hey guys
can someone explain spark plug gapping? the auto parts site i was looking at had the motorcraft at .044 for my 1984 3.8 engine, and then i was looking at the specs on ericscoolcats and it is listed by ford as .054 . does that mean they are the wrong ones on the parts website, or do they have to be regapped?
also are the motorcraft good , or is there better ones . the car has 117,000 miles on it and im not sure if something different should be used on higher mileage cars.
i know when i had my 1995 towncar i tried a different brand of wires and plugs and the car ran like :toilet:  the 4.6 on it was very touchy to that stuff.
thanks for any help
eddie
Title: spark plug ???
Post by: blackcougar71 on January 28, 2010, 12:27:30 AM
for my 84 cougar v6 that's all i used motorcraft spark plugs. since i use to work at a parts store i was able to try every kind of plug for a little bit cheaper then usually and notice that factory type plugs work the best. like for ford use only motorcraft or autolite, chevy used only ac delco and etc.
Title: spark plug ???
Post by: softtouch on January 28, 2010, 12:43:37 AM
The decal on the fan shroud of my 84 3.8 T-Bird says .042-.046
Title: spark plug ???
Post by: TurboCoupe50 on January 28, 2010, 04:37:49 PM
Setum at .040 and don't worry about it... On std copper plugs that will give you about 7500 miles before they've worn to .042-.044... Wider gaps allow more voltage to build in the coil for a slightly hotter spark, down side is the higher voltage burns up the plug wires... Unless you want to rep plug wires ever 30-40K mi, forget you ever heard of setting a plug at more than .050...

I just replaced the plugs about 10 days ago in the beater '93 Grand Marquis(started skipping on #8), yep they're set at .040...
Title: spark plug ???
Post by: blackcat85 on January 31, 2010, 05:06:47 PM
thats what i was thinking blackcougar... i like OEM stuff, but ya never know.

interesting info on the plug gaps turbo....  i guess they would like them set higher so you spend more ???
Title: spark plug ???
Post by: jandmmustangs on January 31, 2010, 05:42:14 PM
Quote from: TurboCoupe50;308221
Setum at .040 and don't worry about it... On std copper plugs that will give you about 7500 miles before they've worn to .042-.044... Wider gaps allow more voltage to build in the coil for a slightly hotter spark, down side is the higher voltage burns up the plug wires... Unless you want to rep plug wires ever 30-40K mi, forget you ever heard of setting a plug at more than .050...

I just replaced the plugs about 10 days ago in the beater '93 Grand Marquis(started skipping on #8), yep they're set at .040...


What he said.  Unless you're running a CD or Digital Ignition Id stick to the manufacturer specs.