Plug Gap
 

Just wanted to see what i should be gapping my plugs at. Its a pretty much stock motor out of a 95 gt and its been converted to carb using a performer rpm air gap manifold and a demon carb.

.054 is a good starting point.

Yeah that should be fine. I know off hand that fox body 5.0's have a recommended gap of .050 I believe.

The factory gap is .044, dont go over .050 unless you have an aftermarket ignition system.

That's interesting! I thought factory gap was .054". I guess you learn something everyday. :) Thanks, Dark.

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Factory gap is 0.054 inches.

isn't factory gap .054?

Please excuse my retarded post stock plug gap is .054.

I meant to say dont go over .060 without an aftermarket ignition.

:o :o :o

i installed the following:
FMS 9mm wires
autolite plugs @ .054
msd blaster coil
msd cap/rotor

how much can i increase the gap?

will be installing an msd6a soon,
how much can i increase the gap after the ignition is in?

There's no need to increase the gap past .054". With a healthy inginition system and proper timing you should be getting a complete burn without any issues.

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In one of my 5.0 tuner books they picked up 8rwhp on a stock engine with an ignition system and increasing plug gap to .060

They picked up like 10rwhp with an aftermarket ignition and a plug gap of .060 on a modified motor.

Both compared to the stock ignition. I wouldnt doubt if they messed with the timing to achieve those numbers:rolleyes:

I have my plug gap set at .060 and I shift @ 6000rpms without any issues.

8 RWHP gain on a stock motor with only an additional .006" gap?

That sounds like F&F talk to me. Maybe more of the gain was attributable to the aftermarket ignition system? Of course, I thought the stocker was fine for minor bolt-ons. :confused:

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Yeah the .060 in conjunction with the ignition system is what attributed to the HP gain.

The stock ignition is fine for a modified 5.0 but there is power to be had by increasing plug gap with an aftermarket ignition.

They didnt see much of a gain until they increased the plug gap so I guess what they were saying is you have to increase spark plug gap to take advantage of your after market ignition.

Cool. Thanks for the info.

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I've also heard of filing back the ground electrode on the plug to be even with the + electrode to unshroud the spark for more initial burn area, just a thought - seemed to work on my friend's SAAB turbo but i have nothing to back it up :D

Better ignition system = more gap
blown application = less gap

better ignition with a blown app = somewhere in the middle?