in all honesty NGK's will probably work the best anyway.

im not sure of the heat range, just asked the shop if they had autolite 985's (the long projection plugs that mock charges 8 bucks a pop for.)

others here have bunged em in and been ok.

ill have to chuck the old set back in for comparison. though the old BUMOMETER says there is more low end pull and top end surge (along with the weirdness at 2800-3000). i just took it out again, and did a few various tests about some roads outside of town and out on the highway, and 6 times out of 10 it went funny at that precise rpm range.

thats a close up of one of the old plugs, somewhere around 1.8mm gap with wear down, and they run fine.

i must admit im only using a millimetric tapemeasure for these dont have a feeler gauge.

Regardless of what worked on the old plugs, regap these ones.
Buy a little plug gapping tool or feeler gauges, they are cheap as chips from TTI or even supercheap would have something I'd think?

found something on plug 2 when i was taking them out to regap them.

i put an extra collapsable collar on the no2 plug to get it closer to a good index (im experimenting with indexing for the first time). the extra collar came off one of the old plugs. when i took out no2 plug i found the old collar had split when it was tightened and it was the bottom collar in contact with the head. dont know if that had put something out of whack not having the plug 100% tight to the head?

I used a 5c coin as a guide to regap them to aprox 1.2-3mm

(australian mint says they were 1.30mm thick when introduced- take into acount a possible wear factor and you have a 100% garaunteed 1.2-3mm gap )

since removing the broken collar on plug2 and verifying the gap aginst the coin ( all were a bees d**k off, so would have been spot on 1.5mm) i went for a short run with good success.

will go for a highway run tonight when the trafic is light.

thanks for the help guys, hopefully its right now.

Dont take this the wrong way (im not being harsh here) but stop wasting your time and stop messing around with coins and crap, go buy some feeler gauges and set them to 1.1.
Regardless of what your coil says, gap them down, it will solve the problem.
Even if it worked before with different plugs, different plugs require different voltages to make a spark. Iridiums for example need a higher voltage thats why they are used mainly on COP setups.

The bigger the gap, the more load your putting on the ignition system, you will burn leads out, burn coils out and if your lucky you can also burn the coil drivers within the ecu if the plug consistantly misfires.

Bigger gaps are not going to nett you any more power. You will get a hotter spark with a smaller gap - you have already found this by it breaking down with the big gaps.

If you want to run huge gaps, then make sure the leads are upto it (stainless spiral wound) and invest in a 3 channel CDI.

Id like to know how Ive just wasted time when the problem is solved? Im not driving into melton (since they dont have any auto stores here in hicktown) to buy a set of feelers when i can get the job done the same right here. There is nothing huge about this gap.

The car is running spot on with a 1.3mm gap. the difference to 1.1mm is almost non visible to the naked eye. I use spiral wound leads and a high output coilpack designed to be run with a higher gap than Im running.



again: problem solved.