The plugs are now gapped at 0.021 and still blowing out. I was told to try using coppers, any thoughts?[/QUOTE]
NGK plugs come in
standard copper - V-power
platinum - G-power,
double platinum - Laser Platinum
iridium - Iridium IX
All four types have copper electrode cores, V groove or V power are referred to as copper but contain no more copper than the other 3 types of plugs.
All four have Nickel ground electrode core material.
All four have copper center electrode core material.
The center electrode tip is what differs, V-power is nickel
G-power and double platinum is platinum.
Iridium is iridium.
NGK state : The V-power plugs lower ignition system voltage requirements. Nobody is going to lower ignition system voltage on their car because they put in V-power plugs, I interpret this as saying with your currents ignition system voltage you will get the most spark from the cheapest of the four types of plugs.
I don't think the V-power plugs are better because of the electrode tip material, I think they work better because of the electrode tips shape. The Vpower tip is thick, the same size as the center electrode that runs through the plug and with the V cut in the tip this makes the sparks discharge surface even bigger, if you compare it to the needle size tips of the platinum and iridium plugs it explains why the V-power plugs have the least resistance.
Think of electricity flowing like water trough a garden hose, the end of the hose is the electrode tip, if you put nothing on the end you get the most water out of the hose, when you put a small tip on the end of the hose water pressure in the hose builds from resistance and you get a stronger smaller spray but less water, the difference is the water that doesn't come out the tip is still in the hose or pipes but the electricity that didn't get to the tip of the plug isn't waiting in the wire for the next ignition sequence it diccipate's into heat.
A while back I bought a 1990 626 dx auto, dirt cheap, they where selling it because it would start in any type of damp weather making it extremely unreliable, the owner put in new plugs and wires on the car within the last 6months.
It was raining the night we picked up the car, I brought an N/A coil, dissi and wires I had lying around and threw them on the car, it started, we drove it to the shop, turned it off and it wouldn't start again unless we put in another warm/dry dissi, coil and wires and would start after idling just 1 minute. Pushed it in the shop and pulled a spark plug out, it was a Champion spark plug with a little needle sized tip, I threw the 4 plugs out and installed the oldest, dirtiest, yellow baked pretty sure they where factory original from a GT we bought ngk Vpower plugs (14-16 years old), I didn't know the N/A and GT's ran the same part numbers at that time or gap the plugs but didn't care, anything would be better than the champion plugs, put the original coil, distributor and cheap grey wires back on and the car started, ran better and always started after that. Sold it to one of the guys renting a garage in the same building as mine and he drove the car for years.
The lesson for me was champion plugs and tiny electrodes suck.
The lesson for the guy I bought the car from was that trying to save a few $ (Buying the cheapest plugs and wires he could) and assuming all things are equal (That because the plugs and wires are new they cant be the problem, who makes stuff that doesn't work?) basically cost him his car, it was 14 years old, under 120 000km, no rust and plated Quebec, easily worth 1500-2000$ at the time. We paid 150$ for it.