Where to gap plugs at?

[92Stang302]

Hey guys i just got new Autolites 25 this is my setup as of now where should i gap them at?

mods listed below:

B303 Cam
65mm throttle body
65mm egr plate
GT40 heads (less then 1500miles, w/ 3 angle valve job, new burrilium valve guides and seals)
Crane 1.7 RR
Trick Flow valve springs
MSD Blaster Coil
190 Fuel pump
BBK long tube headers
BBK Off-road h-pipe
Flowmaster 2 chamber muffs
Richmond 3.55:1 gears
A/C Delete

 

[PURESTREET5006]

Do you have the stock ignition system? if so .052 is ok..And if you have a MSD sysytem on the car then .045 wouls be fine.

 

[Legendary]

My mods are very close to 92Stang302 and I have the MSD 6al and the plugs gapped at .052. Would that hurt anything?

 

[PURESTREET5006]

If you have an MSD system? I would close that gap to .045 That way you won't get a misfire.

 

[Michael Yount]

With the MSD you ought to be able to run more gap than stock, not less - that's one of the benefits of the higher energy ignition system. I'd stick them in at .055 or .060 and see what you get.

As far as where to gap them, I'd gap them between the center electrode and the ground tip.

 

[HISSIN50]

Legendary, i think one of your threads about the gap of plugs had me saying the same thing as Herr Yount. i still dont get why people say to run smaller gaps with N/A motors and aftermarket ignitions. i guess i wont do one since they are weaker than stock.

edit: here we go
http://forums.stangnet.com/showthread.php?t=431396

 

[92Stang302]

all i have is a msd blaster coil i dont have the msd 6al box where to gap at?

 

[Michael Yount]

Stock gap in the .050"-.054" range

 

[92Stang302]

i need more feedback im putting in my new plugs soon, i checked the plugs that are in the car now they are gapped at .40 and their motorcraft 32c's AWSF i purchased auto lites 25's to put in there, so i guess i should gap them the same as what was in the car when i bought it works fine?. GUYS LET ME KNOW I NEED FEED BACK!!

 

[RickyB]

just use the biggest gap you can safely run w/o hesitation, misfiring, spark blowout blah blah blah

 

[HISSIN50]

since there are two different schools of thought, i dont want to make bad recommmendations. were it me, with the coil you have, i would leave it at the stock gap or what you were running before if you have reason to believe it was like that for a reason.
you are not going to have the benefit of more voltage or multiple spark without the box to accompany the coil.

as far as i know (and the way i have always tested it), is that you can open the gap until it starts to miss or cut out at any time in the rev range. then back it off a little.

this does mean the ignition system has to be working optimally. if one's ignition is weak, then close the gap some. i always gap a little tight to allow gap erosion and to allow for the fact that things are not new. but if one has an aftermarket box and coil, i would open it as Michael says (or are you going by Mikee now?).
that seems clear as mud. LOL. my two cents worth. good luck.

 

[Michael Yount]

I'm with Hissin' - stock set up, or stock with better coil I'd run .050"-.054". With a high energy ignition (MSD, Crane, Jacobs, etc.) I'd run as much gap as I could get away with. The more space that spark jumps across - the more mixture is exposed to spark -- that's a good thing for quicker and more complete combustion.

 

[92Stang302]

My heads are cast iron gt40p i think its autolite 25's?... WHY WERE MY ORINGINAL Plugs in my car they were running fine gapped at .40? where the hell should i gap my plugs PLEASE i need a definte awsner.

 

[92Stang302]

well i still dont know where to gap.

 

[93 teal terror]

Theres no definite answer....your going to have to try and see what works for you. If you want a definite answer. Try stock settings and if it runs like crap go to whatever you had them at before. You may be surprised at how much power youll pick up running them at stock settings vs. your .040 If it runs worse...no harm just gap them back at .040, but i can't on earth see why it would run better that way.

 

[92Stang302]

So where to gap them at??.. when i bought the car and plugged out what was in there was motorcraft 32c awsf gapped at 40 the car runs good but those plugs are old, i got some auto lite 25's so i heard is good for the car and it should work with the gt40p heads (cast iron) so where do i gap .40 cuz that is where the orignal was or .45 or .50?

 

[rbridges]

go with the stock range. The absolute worse thing that will happen is that it will run rough and you'll have to regap them. All of 15 minutes work.

You don't close the gap on N/A motors, you close it on supercharged motors. .040 seems really narrow to me. Mine are at .035 b/c I have a supercharger. I ran them at .054 before it was bolted on.

 

[92Stang302]

Guess wut gang i got the 764's in there gapped about 42 where about the range the plugs i took out where and it runs great, just took it for a nice test drive runs solid.

 

[PURESTREET5006]

Keep them at .040 that should be good enough and keep you out of misfire.

 

[Michael Yount]

Seems to me the question has been asked and answered numerous times in the thread. .050"-.054"; if you don't like that answer, then keep pushing it back to the top and perhaps someone will give you another answer that you like better. Alternatively, if you already have an answer in mind - just go ahead and gap 'em to whatever answer it is you're looking for.