[64speed]

I watched the episode of Engine Masters where they tested plugs. Other than maybe a little longevity there was no difference between a cheap champion and an expensive NGK. It’s an interesting watch. Anyway, I’m gonna take everyone’s council and experiment with a little hotter.

[Dragncar]

Originally Posted by 64speed

I watched the episode of Engine Masters where they tested plugs. Other than maybe a little longevity there was no difference between a cheap champion and an expensive NGK. It’s an interesting watch. Anyway, I’m gonna take everyone’s council and experiment with a little hotter.

Except the cheap Champions are two piece and can and do come apart. Nothing will ruin your day like your engine sounding funny, checking it and finding half a Chumpion in your flopping around plug wire and wondering if what was left was bouncing around your engine !
Only Champion Race plugs for me ! They are one piece.

[Formulas]

I have only one spark plug break on me and it was a champion .... brand new set.. ..... engine started missing the next day and drove me crazy for a day or two checking things that were irrelevant pulled the plugs out and one had over double the proper gap somehow the center electrode had broken and moved

[JSchmitz]

Originally Posted by 64speed

Just thought y’all would find this funny. The erratic idle was the pcv inlet at the back of the carb was loose and wiggly in the base. I got another one from Holley and it cured the erratic idle like that.

Seems like one of the rude guys suggested checking your PCV.

[JSchmitz]

Originally Posted by Formulas

I have only one spark plug break on me and it was a champion .... brand new set.. ..... engine started missing the next day and drove me crazy for a day or two checking things that were irrelevant pulled the plugs out and one had over double the proper gap somehow the center electrode had broken and moved

I had a few bad experiences with Champion plugs year ago. Avoided them ever since.

[64speed]

Originally Posted by JSchmitz

Seems like one of the rude guys suggested checking your PCV.

Touché, I did check the PCV valve though just didn’t feel the port to be loose till I really started digging

[Dragncar]

I use Champions, in my lawn mower.

[JSchmitz]

Originally Posted by 64speed

Touché, I did check the PCV valve though just didn’t feel the port to be loose till I really started digging

Glad to hear that you found something to improve your problem.

[64speed]

Ok so I’m obtuse. Is everyone of the consensus that NGK are the best? If so what plug should I get that meets all the requirements.

[Formulajones]

Eh, there ok I guess for a Japanese plug. I mean they work ok, just a pet pieve of mine but leave it to the Japanese to get the heat range numbers backwards (higher number is colder) complete opposite of every other plug on the planet so you need to have a good idea of heat ranges used with other plugs and what the engine likes and then make educated decisions corresponding to the Japanese plug.

You can follow a chart to get close....kinda

[chiphead]

Originally Posted by steve25

Well that fix should help the carb not sence a lower vacuum level which would make it run richer than need be all the time.

It’s good that you found that.

Here’s a picture of plugs out of a forum members car .
His handle is the Soup man.

The motor is a 428 with iron # 47 heads on it that I ported and he runs a good size hydro roller cam .
The motor is run on pump gas and plugs have 100 miles on them.

This is what I would expect out of any street strip motor that’s built right and tuned correctly.

This is what my NGK XR5s look like after a few hundred miles..... New! I went for a 60 mile drive last Friday, Average 55-65MPH at 2500 RPM with a few WOT blasts. AFRs were in the 13s-12s at cruise and 11s-10s at WOT. I just checked 2 plugs and they are white, but with a fuel ring at the bottom. I expected them to color up but they didn't..... 400 with 62 heads and 2802 cam, QF double pumper. 93 octane E10. I'm trying to get the AFRs out of the 10s and 11s but confused how the plugs have so little color.

If you guys remember, I've got like a 8 page thread on tuning my carb. It's paid dividends, when I bought the car, it was turning plugs into black lumps. Now it's running too clean! Most of the plug fouling is the blubbering rich idle circuit. That's usually due to improper throttle blade settings, transition slot idiocy along with IFR and LSAB and mixture screws. Taking the IFRs from 33 to 30, and moving to the low location made a HUGE difference. These modern holley clones are really farked up.

So I don't see how the OP's black plugs are OK on modern pump fuel. Is this straight gas?

What carb is on this engine? And get an O2 sensor, otherwise you're totally guessing what the carb is doing.

[64speed]

R45TS? Is that the plug I “probably” need

[Formulajones]

Not for an aluminum head. Those are small short plug with taper seat for iron heads and not a 3/4" reach that you need with aluminum.

The "T" is for taper seat and the "S" is extended tip.

Don't know the AC part number for the aluminum heads, it's some weird number for the 3/4" reach stuff. I gave up on AC delco a long time ago when they started jumbling their numbers around and seemed to get rid of some heat ranges I was using. They became harder to find around here. Especially when it came to 3/4" reach stuff they weren't using the same heat range numbers that they did with the old stuff.

So I moved on to Autolite and have been happy since. Once in a while I'll use an NGK. I avoid Champion and AC delco.