Spark plugs?

[Bassman/NZ]

I have had bad experiences with Champion plugs in the past, and now I'm having the same with NGK. Out of a set of 8, two are bad. My alternatives seem to be Autolite, Motorcraft, AC/Delco, or Bosch. Any negatives on these other brands?

[Old Henry]

I like the looks of Autolite with the black bottoms and have had no problems with them.

[52merc]

marty I also have had spark plug problems in the past also with ngk I brought a new set while stateside they have three elctrodes I don't think there on the market here yet..they are e3.52 diamond fire technology 100,000 mile and 5 year warrenty see if you can get it on google ive had no problems with them at all trev

[4dFord/SC]

I have good luck with Autolite.

[mike42]

Ditto on the Autolites. No probs at all.

Mike

[Ross6860]

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We have tested about every brand of spark plug on the market over the last 20 or so years (engine oils, too).

Stitt, Autolite, Bosch, NGK, and who knows what else.

Bottom line is we always come back to Champion. Yes, we occasionally get a couple bad ones. It really hurts when some of our plugs are around $100 a pop.

I've only run Champion in my personal stuff.

We run a bunch of industrial engines (several dozens) that run 24/7/365. We have run Fords, Chevy, Hercules, Cat, even Mazda rotaries in the small stuff. Cat and Waukesha in the bigger high and medium-speed world, and Cooper, Clark, and Superiors. Needless to say we buy hundreds of spark plugs a year.

PS - You should see the exhaust pipe on a full load turbocharged Mazda 13B after it's been up to temp for an hour or so. You can see all the colors of hot steel as it progresses from near white/orange, to orange to red to dull red. Pretty cool. They suck fuel like a pig but they make gobs of power for a tiny little thing

[Willit Stop]

I had a plug problem a while back.At idle,the needle on the vacuum gauge would wiggle a little and the engine would not idle smooth.One at a time, I shorted the wire to a head bolt and got a very strong spark.Then I shorted it to the plug and got a weak spark that would only jump about 1/16 to 1/8 inch.If I remember correctly,the plugs were Autolite 386's.They may have been resistor plugs but I'm not a tune up expert so that may not be accurate.Anyway,I took Ken ct's advice and switched to Champion D-21's.What a difference! The vac gauge was steady the idle was smooth and the spark was strong (thanks again Ken).Just my experience. Gene

[franksford]

I also had a big problem with NGK with using them with a 59a engine using Navarro heads. Autolite made all issues go away. Frank

[oldford2]

Although Vic wouldn't put Champions in his lawn mower, In the last 5500 miles (2 years) I have the same set of Champion H-12's still sparking like a "champ" (pun intended). I think some plugs get a bad rap due to a poorly tuned engine. JMO
John

[JT FORD]

#216 Autolites for me...had Champions. They weren't any good in the '50s either.

[trevo]

Bassman, I am running Champion H10s had them in 3years been to the Beach Hop all round Whitianga Art Deco Parades etc no issues but my motocycles have thrown up dodgy Champion and NGK which are all fitted with Trispark electronics wonder if they fail because of the extra current, do you have electronics in your car?

[Bassman/NZ]

Originally Posted by trevo

Bassman, I am running Champion H10s had them in 3years been to the Beach Hop all round Whitianga Art Deco Parades etc no issues but my motocycles have thrown up dodgy Champion and NGK which are all fitted with Trispark electronics wonder if they fail because of the extra current, do you have electronics in your car?

Hi Trevo, no electronics here. I'm going to try another set of Champion H10s and see how they go.

[Talkwrench]

Bad NGK...? All my cars have NGK's and never an issue.
I broke the Champion one day in the F/Head and replaced with NGK AB6 or A6 ?seems fine, been in for hundreds of miles now, I do have electronic Ign.

I know of someone who also had Champs break in his F/Head. He had a new box of Champs and they stated to break too !! Holy Hell somethin' aint right there.

[49r]

I've run Champion H10's for 40 years in various flatheads and never had a problem - maybe I've been lucky ...

[Tom Walker]

How do you know when you've got a bad plug in a V8? How do you tell which cylinder has a bad plug? Replace one at a time?

[MARVIN, CT]

My 60hp came with Champion j8c plugs. Seem to be ok, any other suggestions? Just like to maximize my options. Thanks, Marvin,ct

[Bassman/NZ]

Originally Posted by Tom Walker

How do you know when you've got a bad plug in a V8? How do you tell which cylinder has a bad plug? Replace one at a time?

Bad plug is wet.

[Karl Wolf]

Pull all the plug wires loose start up the engine and remove one at a time... If your wire ends are open, short them out with a screw driver... Look for a RPM change.
Karl

[Bassman/NZ]

I put in a new set of Champion H10s, and it runs like a top. The NGKs I took out only had a few miles on them, but two of them just died.

[my4dv8]

Originally Posted by Tom Walker

How do you know when you've got a bad plug in a V8? How do you tell which cylinder has a bad plug? Replace one at a time?

Finding a bad plug should be a simple process of pull a plug do a colour ID and movie to the next one. If one is shown to be dark or fuelie you need to ascertain why. Bad plug bad lead or poor cylinder??? it's not always an easy process of elimination but that's how it has to be done,.