Engine Builders- Testing Types And Brands Of Spark,Plugs ?

[427HISS]

I know that most guys have a brand of spark plugs and even the types they like best, but have any of you engine builders tested them on the dyno ?
I've either used Denso or NGK, but other than looking very close at issues like oil, white, grey & black colors, electrode problem. I have index sets before, but I don't have the testing ability to gauge various types of plug's and manufacturers.

Does the FE heads have a best type, brand and gap that work better as a ''all-around'' plug ?

Copper/nickel, iridium, single platinum, double platinum, and silver.

Just one list, but I'm really wanting professional testing.


In This Article

The 5 Top-Rated Spark Plugs
Our Top Pick: NGK 6619 Iridium Spark Plugs
Runner-Up: Bosch 4417 Platinum+4 FGR7DQP Spark Plug
Budget Pick: Denso (4503) PK20TT Platinum TT Spark Plug
Best Iridium Spark Plugs: NGK 5464 BKR5EIX-11 Iridium IX Spark Plug
Best Platinum Spark Plugs: NGK (7092) BKR6EGP G-Power Spark Plug
Who Should Buy a Spark Plug?
Important Features to Consider
Frequently Asked Questions
Other Spark Plugs We Reviewed
Iridium Spark Plugs
Platinum Spark Plugs
Copper Spark Plugs

Types-

https://www.thedrive.com/reviews/27526/best-spark-plugs

[GerryP]

Most is just marketing.  The best plug is the one that has the right heat range, the right plug tip projection, and most importantly, the right gap.  There was a time, long, long ago, where Champion was the plug of choice.  Not universally, but widely.  The rare earth construction, like iridium and platinum,  is a red herring.  Those are corrosion-resistant metals so the plugs will go for those 100k+ mile tune up distances.  And that was largely an emissions consideration since a plug misfire will quickly kill a catalytic converter.  So, the days of 12k mile plugs are gone.  That's due to the high energy computer controlled ignitions.  You can get a low tech plug to go 40k+ miles these days.  Things like coil-on-plug and near plug, distributorless ignitions reduce the failure modes for ignitions.

It's just not practical and in many cases even realistically possible to compare two plugs of different construction and declare a winner.  There will be variations in heat range, optimal timing advance for that particular plug, optimal plug gap, and plug position in the chamber.  Kind of F1 and NASCAR engine shop levels of testing.  And this is worth repeating;  You can have the perfect plug for combustion in your engine, but you can easily miss on your ignition tune up and not realize that advantage.  I would find it hard to believe that anyone with a street car is running the most perfect ignition timing and getting everything a particular plug can give for all circumstances.  A race engine is a different story.

So, screw a plug in those heads.  If it doesn't blow out or load up, you're most of the way there.  Whatever name is on the porcelain, don't worry, be happy.

Others may have a different opinion.

[My427stang]

I agree, and in some cases, the fancy stuff isn't happy with CD ignition

I run standard Autolite cor Champion copper core, never an issue

[gt350hr]

   I run Autolite in my street cars. Platinum in the EFI ( factory) and they do go for 100,000 miles. Carbed engines get "regular" Autolites , and my high compression "race only" stuff gets NGKs. Why the switch? I gauge the plug heat by the discoloration of the gold irridite plating on the threads of the NGK. Not because it is a superior plug in any way. Stupid ? No  , lazy on my part.

[WConley]

GerryP speaks wisdom!  Fancy metal plugs erode more slowly.  That's it.  All you need is the right heat range on a good quality name-brand plug and you're set.

If you believe the claims of Splitfire and the like, I've got some Slick50 to sell you.  (Man, I'm starting to sound like Royce Peterson!!)

[gt350hr]

 Those plugs "appear" amazing when ALL EIGHT (coil wire to the plug) cylinders fire through it. looks like an arc welder or Tesla project. Show it firing off of an 8 cylinder distributor cap as it really runs in the engine and it's FAR less dramatic. Same gimmick was used for the MSD multi spark under 3,000 rpm. The multi spark IS functional , don't get me wrong,  but when you "show" it on one plug , it's really dramatic. Multi ground strap plugs have been around for 100 years.

[BattlestarGalactic]

GerryP speaks wisdom!  Fancy metal plugs erode more slowly.  That's it.  All you need is the right heat range on a good quality name-brand plug and you're set.

If you believe the claims of Splitfire and the like, I've got some Slick50 to sell you.  (Man, I'm starting to sound like Royce Peterson!!)

OMG, Splitfires!!      My buddy did a "test" with those many decades ago on his Turbo Coupe T bird(when it was still stock).  I even have the video from the track with him changing them from his Autolites.  Yup, not a bit of difference.  Those commercials where everyone was saying how much of an improvement they were?  Ya, they likely had 100K miles on their plugs and ANY new plug would make a big difference.

[cjshaker]

Multi-ground strap plugs were designed for aircraft use in the '20s. The only advantage they have is if you lose one strap, which was their only purpose. A big deal when you're 1000-15,000 feet in the air, not so much when driving down the road...lol

[Stangman]

My dad bought some E-3 plugs for me and is dying for me to try them. I just dont see the benifit and Im worried they will hit or something weird

[Heo]

GerryP speaks wisdom!  Fancy metal plugs erode more slowly.  That's it.  All you need is the right heat range on a good quality name-brand plug and you're set.

If you believe the claims of Splitfire and the like, I've got some Slick50 to sell you.  (Man, I'm starting to sound like Royce Peterson!!)

Royce Peterson? recognice that name is it the guy with the bigfoot movie from the 60s?

[Joe-JDC]

I helped take part in a dyno test session where we were trying to find out about indexing plugs, brand of plugs, and after establishing a good repeatable base horsepower and torque, we installed a set of the E-3 spark plugs, and lost 8 horsepower.  Tuning did not get it back.  Installed the old Autolite spark plugs, and the 8 horsepower came back.  I was told by the sales representative of E-3 that we were using the wrong heat range, but they were the ones who donated their plugs for testing.  Joe-JDC

[WConley]

Royce Peterson? recognize that name is it the guy with the bigfoot movie from the 60s?

Royce is a well-known Cougar expert, especially for GTE's and CJ cars.  He used to post a lot on the old Forum.  Every once in awhile Royce will pop up over there again.  He's very knowledgeable, but can be quite prickly when somebody brings up a controversial idea.  Royce would famously pop up if someone mentioned a factory W-code Mustang sighting.  "There were NO 427 Mustangs factory produced - EVER!!!  Only the Cougar GTE got a 427 in 1968!!!"

I could see Royce coming down hard against newfangled spark plugs or miracle oil additives.  "It's all bunk!  It'll never work!"  Makes me chuckle. 

[Stangman]

Thanks for the info Joe. Just curious did indexing prove to be fruitful or no.

[Joe-JDC]

Not to open up a can of worms, but indexing on old vintage engines where the sparkplug is not ideally placed, poor combustion chamber design will make a difference.  On the newer combustion chambers with the plug placed near center, or aimed toward the exhaust valve, no difference.  I did several tests on my EMC engines, and did not find any help with power due to good chamber design.  Joe-JDC

[fryedaddy]

i find myself changing a single plug here and there between tuneups.i get my heat gun out and if any of the cylinders are cooler than the others after a minute or two of running or if i have a slight miss etc. so when i buy a set i usually buy 10 or so plugs for this reason.