[i82much]

Has anybody actually worn out a set of spark plugs in a weekend driver? I am replacing a set this weekend, but honestly I could have probably saved myself the 20 bucks and just cleaned up the ones I have. Is there really any difference between buying new plugs and cleaning up a set that has 10k miles on them with some carbon from running a little rich?

Not going to cheap out this time, I already ordered the plugs. But I just got to thinking that I probably drive my old junk what, maybe 3000 miles a year tops between the GTO and the old truck. Chances are I could clean all 16 plugs every winter for the next 20 years and not really need to buy new ones.

[Blued and Painted]

With a dialed in carb and tune, I would think 15K+ miles is possible with an HEI. Multiple Spark Discharge may reduce plug life?

[i82much]

Originally Posted by Blued and Painted

With a dialed in carb and tune, I would think 15K+ miles is possible with an HEI. Multiple Spark Discharge may reduce plug life?

Gosh maybe, I don't know. I ran an MSD for a long time and I don't remember seeing any electrode wear to speak of. But it was a long time ago, and I used to change spark plugs just to pass the time, so maybe I never ran them long enough to see.

I was thinking more like 50k if you pulled them out and cleaned them every once in while!

[TedRamAirII]

As long as the electrode edges are nice and sharp, all is good.

[Blued and Painted]

Has allot to do with spark duration. Anything over 30K would need a Platinum or Iridium Plug.
I don't recommend the wizz-bang plugs or E-3's in these old Dinosaurs. JMO.

[PMD1969]

I pulled a set of plugs off of mine that were over 20 years old and were still "plugging away". We've owned the car since new so its hard to say if they were original to the car but I do know they were at least that old.

This car has been the most reliable car we've ever had. Outside of a leaking oil pan roasting the starter, as soon as the gas hits the engine it fires and runs. Maybe not to the top of tune but it will get you there.

I still run the AC ringed plugs that look somewhat similar to the old style. I also have four or five sets of the originals that look brand new. One of the early sets of originals that I had bought back 10 years ago were still banging away with no issues. I do pull them and check for gap and any bad coloration but then just clean them up a touch and pout them back.

[1968GTO421]

Originally Posted by PMD1969

I still run the AC ringed plugs that look somewhat similar to the old style. I also have four or five sets of the originals that look brand new. One of the early sets of originals that I had bought back 10 years ago were still banging away with no issues. I do pull them and check for gap and any bad coloration but then just clean them up a touch and pout them back.

Yeah, I do that. Also, my budget dictates priorities and "Why fix what ain't broke?"

[HWYSTR455]

Well, OE service intervals are usually 24k miles for standard points ignitions, but Ford duraspark ignitions I think list 12-15k miles. Think about the same is listed for HEIs. These are of course 'standard' plugs, with standard electrodes.

Beyond a certain year, the electrodes changed to a different material, so you have to take that into account. For example, there are a number of Cadillacs that go 100k before a 'tune up'.

Just because a plug 'looks' good doesn't mean it's performing 'optimally'. They can 'work' beyond the recommended interval, but I'm pretty sure the performance will be down.

MSDs and other multi-strike boxes, ones that increase rise time on the coil so they saturate more, wear parts faster, not just plugs either. Like caps, rotors, wires, and coils, all wear faster when under a heavier load. There again, just because they 'look' good, doesn't mean they are performing optimally.

Plug wires are one of the items that most ignore for the longest time, thinking they 'look' good. Blows me away when folks say they haven't changed them in 5+ years and countless miles. I've seen cheap sets last only for hours, really. The best ones I've seen last like 2 years or so, max. If you handle them a lot, less.

Follow general service intervals, or at least use them as a guideline for what intervals work for you. Depending on the system, it should be in the 12-24k miles or 2-3 year range.

.

[Goatracer1]

In 20 years I have never changed the plugs in my GTO. It has Jacob's ignition module and HEI magnetic pickup.

[STEELCITYFIREBIRD]

Highly agree on plug wires and all secondary ignition parts take quite a beating from a MSD box. Especially the coil wire from what I have noticed on my own ride.

[1968GTO421]

Originally Posted by HWYSTR455

Well, OE service intervals are usually 24k miles for standard points ignitions, but Ford duraspark ignitions I think list 12-15k miles. Think about the same is listed for HEIs. These are of course 'standard' plugs, with standard electrodes.

Beyond a certain year, the electrodes changed to a different material, so you have to take that into account. For example, there are a number of Cadillacs that go 100k before a 'tune up'.

Just because a plug 'looks' good doesn't mean it's performing 'optimally'. They can 'work' beyond the recommended interval, but I'm pretty sure the performance will be down.

MSDs and other multi-strike boxes, ones that increase rise time on the coil so they saturate more, wear parts faster, not just plugs either. Like caps, rotors, wires, and coils, all wear faster when under a heavier load. There again, just because they 'look' good, doesn't mean they are performing optimally.

Plug wires are one of the items that most ignore for the longest time, thinking they 'look' good. Blows me away when folks say they haven't changed them in 5+ years and countless miles. I've seen cheap sets last only for hours, really. The best ones I've seen last like 2 years or so, max. If you handle them a lot, less.

Follow general service intervals, or at least use them as a guideline for what intervals work for you. Depending on the system, it should be in the 12-24k miles or 2-3 year range.

.

Thanks for info I had forgotten but used to know....have been getting info overload on these forums

[HWYSTR455]

Originally Posted by Goatracer1

In 20 years I have never changed the plugs in my GTO. It has Jacob's ignition module and HEI magnetic pickup.

I ran the 'blue' Jacobs boxes exclusively, the coils, and wires. When they got bought out, they were 'corporate' offerings/quality. I bailed.

Silicone is silicone, it breaks down over time, dang acid rain and crap! Heh-heh! I bet if you turn all the lights off, and run the engine, you would have a light show!

Lisle Tools used to have a tool that would kinda measure corona of plug wires, get one. Compare what new wires make that light flash over used ones. You will be enlightened.

https://www.amazon.com/Lisle-26900-S.../dp/B000CODRMM


.

[STEELCITYFIREBIRD]

Run your hand near the coil wire of a car running with a MSD box... and be careful where your jnk is parked while reaching!

I was enlightened....dynamically!

[Goatracer1]

I have a pacemaker. I can't be within 2 feet of the ignition system of a running engine. So no thank you.

[geeteeohguy]

I change the plugs in my GTO's at 15,000 miles. Points and condensers, too. By then, the plugs are worn a bit on the center electrode and rounded off some. The plugs are tan in both cars, not black.....I run AC43's in the 389 and 44's in the 400. And have for the past 30+ years.

[Schurkey]

Champion spark plugs were known for soft, fast-wearing electrodes thirty years ago when I swore I'd never buy another Champion plug.

AC had harder, longer-wearing electrodes, as did Autolite and I'm sure others.

I can't say I ever noted a difference in service live when using an MSD box except that I would have said the plugs last LONGER. That is, the engine will fail to misfire even with the plug electrodes pretty beat-up and worn; and I wouldn't say that they wear faster with an MSD versus a single-strike ignition system. Caps, rotors, plug wires seemed to last about the same whether MSD-fired or single-strike.

[Half-Inch Stud]

Knda forgot that my engine has plugs. Seems i service the headbolts more

[Blued and Painted]

Champion spark plugs work great in a lawn mower. But i dont know of any other applications.

[TedRamAirII]

Originally Posted by Blued and Painted

Champion spark plugs work great in a lawn mower. But i dont know of any other applications.

They are OEM for most Chrysler applications, so thats a few million cars and trucks. Quite a few AC DELCO plugs are made by NGK, Motorcraft/Autolite spark plugs are made by Honeywell.

[Half-Inch Stud]

We used Champion (Ohio) Aviation plugs on a UAV, but the plant got bought by Tempest.