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Expensive spark plugs

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The original motorcraft mile long plugs for those 3 valve engines are NOT 1 piece

That is part of the reason why they sometimes separate when you attempt to remove

By the way, these champion plugs were specifically designed for this application only. They are not your generic one size fits all plug

Here’s an excerpt from Smokey Yunick’s autobiography re Champion spark plugs:

“I remember Champion Spark Plug (one of very first to put money in NASCAR). France met Champion’s executives at the Eastern Air Line plane with an elephant. The elephant had a thing like a pickup box strapped on it’s back for them to ride in, and came equipped with two hookers and booze. The two Champion “big shots” (Dick McGeorge and I forgot other cat’s name) rode elephant to the Streamline Hotel, a trip of ’bout three or four miles. I’ll let you guess how that ended. Well Champion put lots of money in NASCAR for ’bout 40 years and in the end they got screwed out of a building they built and paid for at the Daytona track. But don’t cry many tears for Champion. During the last 40 years it’s been run by a bunch of incompetent a**holes, and maybe that’s best way to purge a defective outfit.”

Hahah. Corporate bigwigs are a fascinating demographic. Seriously.

Db, would that be the 4.6L engine?

That would be the 5.4 and 6.8

I’m not so sure about the 3 valve 4.6, but I assume it might also apply, if it also uses the mile long plugs

The idea behind platinum or iridium plugs is a longer change interval - 100k as opposed to 10k miles. With some engines, the design is so mucked up that changing plugs requires a mechanic with special equipment to get at some of the plugs. They are supposed to save the car owner money (big deal, they’re very inexpensive at Amazon.com) and since tune-ups are really a thing of the past (back in the day, as the mindless say), lots of drivers trade their cars in before a plug change is required. Platinum and iridium are hard metals and the plugs don’t wear out as quickly. I have a friend who has over 150K miles on his car’s iridiums and every time he pulls the plugs to check them, he puts them right back in because the gaps haven’t increased. I have over 80K on mine (Bosch iridiums) and the car is as quick as ever it was.

The idea behind platinum or iridium plugs is a longer change interval - 100k as opposed to 10k miles

What engine that uses regular Nickle plating has a 10k change interval? Not even pre-Electronic Ignition was the change interval that low? 35k-50k is the more common range on regular Nickle plated plugs.

I remember plugs were 15k back in the breaker point days.
My '81 '85 & '88 Accords were 30k with copper/nickel plugs.

The main driver behind this were the emission regulations and CAFE rquirements. To get engines to meet emisions regs for any reasonable length of time required upgraded iginition parts such as capacitor discharge instead of points, longer plug life and a more consistent spark. As this happened, better gas mileage was a bonus. To get 50,000 miles out of tailpipe emissions, all components up to the end of the catalytic converter had to be upgraded.

We lived in Malaysia where all these regs were not on the books yet and our locally built car still had the old style plugs. They recommended changing the plugs every second oil change!

We lived in Malaysia where all these regs were not on the books yet and our locally built car still had the old style plugs.

I’m not sure plugs were a big issue to meet the EPA requirements. The requirements that are in place today have been around for over a decade. Regular nickle plated plugs are still being used in many cars today. I know the 4runner was still using nickle plated plugs until 2010.

The iridium and platinum plugs do have a performance advantage over the nickel plated plugs, but under most circumstances, it is not measurable. The thinner tip causes a more dense corona to form around the tip when it fires so it is actually a hotter spark, and it fires more reliably under extremes of the fuel/air ratios.

The iridium and platinum plugs may not be used in racing, but neither are the regular nickel plated plugs. The tips have a special shape that does not last very long, but then they are changed very frequently so long life is not a consideration.

Back in the day of points and unleaded fuel, 10-12k changes for plugs was common. The tune-up was an annual affair. But then oil changes were bi-monthly or 1500 miles back then. The lead was hard on plugs, oil and valves.

I seem to recall changing plugs every 10K on my '64 Fairlane. But there were factors affecting that other than the electrode material. I seem to recall frequent plug changes on my '72 Vega too, although I cannot remember how frequent. As with the Fairlane, the reasons were not all in the electrodes.

The reason for the more frequent spark plug changes in the old days usually revolved around leaded gasoline deposits which affected more than the spark plugs.
Compare the deposits on piston tops and cylinder head combustion chambers on an old leaded gas engine with the ones from an unleaded engine. There’s a night and day difference.

The Roadrunner I had back in the leaded gas days was equipped with the 383 Magnum and three weeks of in-town driving without keeping the revs up would start fouling the plugs.

Same for the Superbee I had and that presented the Catch 22; drive it easy and increase fuel mileage (as much as possible) or keep it revved up which would keep the plugs cleaner but made the gas gauge whimper…

The iridium and platinum plugs do have a performance advantage over the nickel plated plugs, but under most circumstances, it is not measurable.

I don’t think so. If there were then every race car would be using it. Every race car builder/driver would sell their mother for a .001% advantage.

Performance criteria spans a broad range of parameters. Race cars aren’t concerned about resistance to long term fouling or extended lifetime, two areas where Iridium plugs have a performance advantage over “conventional” plugs. The race is over pretty quickly by comparison and the plugs changed if not the entire engine rebuilt after every race.

Performance criteria spans a broad range of parameters. Race cars aren't concerned about resistance to long term fouling or extended lifetime, two areas where Iridium plugs have a performance advantage over "conventional" plugs

Correct…So if the iridium plugs increased performance by even .01%…they’d be using them. They don’t…There is no need.

They don’t care about fouling, the race doesn’t last long enough for that to be a concern. Anti-fouling is still considered a performance criteria, just not for race cars…

Anti-fouling is still considered a performance criteria, just not for race cars...

Exactly…So the ONLY reason a race team would use them is IF they provided better performance…even .01%…And they don’t…thus they don’t use them.

Mike, have you ever seen the tip of a racing plug?

http://www.ngk.de/fileadmin/Dokumente/EN/Kataloge/SparkPlug_GlowPlug_2013_2014_EAST.pdf see page 23.

http://www.autolite.com/products/racing-spark-plugs.aspx

They do use iridium tips on some, some are surface gaped and some just use a cut back anode. The cut back anode was popular, and the only option back in the day (60’s) unless you went to aviation type plugs which were multi anode or surface gap.

I used to cutback the anode on my spark plugs myself, but they would only last about a 1000 miles.

Here’s a few examples of high performance race plugs for ya…