Which way does the compression ring go on a plug... larger diameter side to plug or head? It's been years since I changed plugs on anything, and the last time I did, the rings were already on the plugs.

I'd been getting some spark knock on hard acceleration, so I moved up to 89 octane... didn't change. I figured that maybe someone had put platinum plugs in, since y'all say they can cause detonation. I picked up some Autolite 5224s tonight, (no Champions to be had on Sunday around here) to install tomorrow. Meanwhile, to get an idea of what's going on, I pulled one of the plugs, and it has Autolites in already, so the knock can not be blamed on platinum plugs. I did notice that the gap of this plug was way big at almost 0.055, so I pulled another, and it too was around 0.055. Can a gap that largecause knock, or do I need to look elsewhere for the answer?

 

Large gap will make a bigger spark, which will burn the fuel better IF the coil has the ***** to fire the gap. The downside to running that large of a gap is that each spark will wear the electrodes even more than a smaller gap, so you have to change the plugs more frequently.

Will it cause knock? No.

What causes knock -
carbon deposits
too "hot" of a plug
timing too far advanced
a/f out of whack

How many miles are on that, how old is the O2 sensor? Are those MAF based engines? If so, has the MAF been cleaned? Check for a vacuum leak. hmmm, Off the top of my head I don't know what else to suggest right now

 

You could try running some sea foam through the vacuum that will clean the carbon up! Watch for smoke. lol

 

Finally got the plugs changed today. Had to wait on the stealer to get me 3 of the o-rings that are used to seal the coils. The goober who changed them last, I guess, didn't care that they were missing, orthattwo of the plugs were just barely tight. Also, a couple of 'em had gaps in excess of 0.060. I don't know if the large gaps were due to not doing it right from the get go, or these plugs have been in a loooong time. The center electrodes did not look burned up at all, they still had a pretty flat top, who knows... that's enough of that rambling. The new ones all got gapped to 0.040, and torqued down to 20lbs.

The good parts of this story are... THIS MOTOR NOW SCREAMS!!! The plug change really woke it up! AND, believe it or not... THE SPARK KNOCK IS GONE!!I don't know how or why, but I'm not going to look a gift horse in the mouth.

I'll leave these Autolites in for awhile, and probably change them out for the Champions or NGKs later on. I always had great luck outta NGK in the past.