302 87' & 93' gapping 1 quest./ 4 forums / 0 answers
 

Maybe it's a misprint,but motorcraft online parts cat. where you enter Mk./Yr./Mod./Eng. and it coughs up the specific part #'s, gives the same part#'s for Distrib., Cap, Coil. & Plugs for both 87' & 93' (N) 302's. BUT Here lies the rub! The Gap to use on the same plug screwed into the 87 is .044. but screw it into a 93 and the gap should now be .054 stock! and if I want to run that gap on my 87 I'm told I'll need to bolt on sumore Volts? I've posted this ? on 4 forums where their continuing to gather dust even now. answers have ranged from nada to one or more vowel sounds, but not in a row. If its incorrect motorcraft info and whatever year the gap increase occurred was the year they ran out of the cute little coils but had alot of the bigger ugly ones laying around. I'd still like to know?

just follow what the sticker under the hood says. the 87 should be .044 and the 93 .054. i think it was changed for emmission purposes. and all the parts are the same.

Thanks for replying. that's a reasonable premise but then how does the 93' run good & cleaner w/ .054 gap stock but the 87' w/ that gap misses and runs over rich? While Knowing why the gap mod was done is good, I'm reeeeeally interested in how they achieve this when ignition components are identical down to the plugs and so far, it seems like everything else, except speedo system. Maybe I'm wording it wrong!......."How does the 93' 302 having the identical ignition components as the 87' 302, run with .054 plug gap stock. But the 87' 302 requires a High output coil mod to allow the same .054 gap to be used???????? Maybe I should switch to searching for some answer I might have better luck with. That Holy Grail thing's still M.I.A. isn't it? Anyway, looking around for the answer to the gaping question I learned about Side Gaping. Doing that to a set of Motorcraft coppers & a 2 degree timing bump got me a bit stronger acceleration and when I kept my foot out of it, 2 mpg's. But if anyone happens to know whats up with the gaping question, I'd really appreciate knowing!

my manual says that it was widened to allow the engine to run significantly longer on a set of spark plugs. but efficiency and power and fuel economy will drop a little bit.

That seems odd to me considering the gap grows over time. I would think smaller gap would leed to longer plug life. I gap the plugs in my Mach I at .45. It has a modernized ignition system MSD 6AL MSD pro billet distributor Mallory pro blaster coil. I asked around and the general conciseness was .45 but I think I could run way bigger and it would still work all that voltage going though there. I've removed plugs out of old EFI 351w's the gap had grown ro nearly .90 Modern ignition systems arent very gap sensitive like the old low voltage points ignitions.

i dont know the whole deal with it. like i said that was what my manual says. i think smaller gaps wear out a little faster.

So when when it was decided to make .054 the new gap to be used, increased from .044 spec'ed on prior 302's from then on, Ford made no changes hardware wise (validating motorcraft listing the same part #'s for 302's ignition proir to and after they officially increased the gap size (87-95).The manual's statement is only correct if the engine ign. sys. is insufficient to span the increased gap which is why I keep thinking their must be some mod that was done to enable 302's to continue producing sufficient spark w/the added gap size still using the identical distributors, coils, even plugs. There's no way Ford would change specs on an engine they knew would reduce power, mpg's a couple years before they were required to implement OBD2 on that engine which will put up w/alot less **** than OBD1 did. UNLESS it was part of the intentional detuneing (done to reduce performance in order to enable maximum drivability & survival with the reduced allowable emmissions standards mandated. This would be a method in addition to the other 2 methods I know of which are purposely fitting the engine with less than optimum intake air flow which reduces call for fuel potential & retarding initial timing to produce a less aggressive timing advance curve. because the level of perfomance the engine is capable of putting out all day long w/o emm. cntrls (13.5:1 air/fuel) is out of the question with them (14.7:1) So began the trade off of performance for more acceptable reliability and usable life span. The initial result of when emission reduction controls where first put into effect, was there started to be more cars parked on the lots waiting for repairs than there were to be sold. Anyway, that would mean 302's that had their gap specs increased to .054 would all experience better performance & MPG's just by reverting to the proir spec for gap of .044 and the only way any 302 could benefit from the .054 gap size would be by modding the stock coil with an increased output coil. Ya's or Na's???? By the way,anybody that runs with additional advancement of their stock initial timing setting, ac/deco dual plat finewire rapidfires give solid performance at increased timing advance settings that plat plugs traditionally were unable to fire cool enough to provide ignition w/o a ping right behind it. and my idle smoothed out to the point I added a tach to reassure myself that that my engine had not stalled while waiting for a light to change. If you don't try these, try Motorcrafts version that's about to go to distribution. Assuming they'll be as good or better otherwise what would be the point of retooling to mass produce them?