Technical What is the best choice in spark plugs

Hey bought a set of NGK today B6L for my 8ba what gap do i need on these whats running the best my autolite 216 was at 25 is 30 to much on the NGK. thanks

 

I have Autolites in my Falcon and Champions in the blown Hemi.

Both are driven by computer controlled CD boxes, so it probably doesn't matter what brand I use.

Both sets show massive blue-white sparks, and hurt like hell if you bump the engine with a plug wire off.

 

b

 

I had a similar conversation with the gentleman who flow-benches Hilborn pumps for me. He is a well-seasoned gentleman who has been running roundy-round cars since the 60's. His view was similar to mine - NGK. One thing he noted (and I've found it right too) is that NGK plugs are gapped well out of the box. I was taught always to check, but have never yet found an NGK plug that was not gapped as per the settings on the box.

He mentioned he had a lot of trouble with a certain type of Champion plug, which was never gapped correctly out of the box. The plugs are a weird design - the ground electrode is not the normal ones I've seen, nor anything that Champion lists on their site:

ChampionIridiumPlugs.com: Champion Ground Electrode Designs

The ground electrode looks like a small steel pin that pushes in from side of the plug. It is not captive - you could push it all the way in until it touched the centre electrode, or pull it all the way out until it fell out the side of the plug. He had both a set of plugs to show me, and the Champion branded tool that will push or pull the little pin to set plug gap. The pin is an interference fit, so the tool is like a miniature press. I've tried to draw what that looks like using the diagrams from the Champion site:



The top image is a standard plug, and the bottom one is the plug type he had. The ground electrode is shown in red to make it easier to explain. I didn't note down the plug part numbers, or the Champion part number stamped on the tool. He made me interested though, but after lots of Googling I cannot find any reference to this plug type. Anyone seen them before?

Cheers,
Harv

 

If you put a small allen-key in the end of a CD-ignition plug wire, you can test to see if you have ignition after breaking down in the middle of nowhere. Hold the plug lead about 2" from the end, with the allen-key near the cylinder head. Have your kids turn the motor over while you watch for spark. The ignition is good enough to jump that far, land you on your butt, and throw the allan key skywards.

Don't ask me how I know

Worst Scintilla Shuffle I have ever done. Made me want to go back to a traditional coil in the avatar.

Cheers,
Harv

 

I bet!

I had chest pains for a few hours after taking a hit from the CD box, so I cannot imagine a mag.

 

Yep, those are the ones. Some parts number Googling shows the design dates back to the 30's, still perhaps used in the 60's. The intent of the "buried" electrode was to prevent a hot, protruding ground electrode from causing pre-ignition. I guess better head design and fuel octane lead to the more common ground electrode "strap" we are familiar with.

Cheers,
Harv

 

Unfortunately Ben passed away a couple years ago.

 

I bought a Snapper snow blower in '85 and sold it about a year ago with the original plug still in it. I always ran the gas out in the spring and when I put fresh non-alchohol gas in it at 1st snow. It usually took 2 pulls on the 1st start of the year and one the rest of the season. I never used the electric start it had except to try it out once in a while to see if it still worked.

Gary

 

Yep always use fresh non ethanol gas, it isn’t that these engines won’t start just takes three four or five pulls, I change the plug and they start on one or two pulls, who knows and plugs are fairly inexpensive
Dan

 

Maybe the air is better in Iowa
Dan

 

Incorrect heat range for the plug and/or incorrect carb adjustment kills plugs. Often a matter of the plug not being able to get hot enough to self clean, i.e. burn off oil, carbon etc. (Getting it red hot with a propane torch can often save them at that point.)
Too much fuel at idle tends to be really good at killing plugs - the extra fuel both cools it so it can't self clean and produces extra stuff that needs to be burned off. At full throttle they tend to keep working as there's rather much heat even when running rich or with a slightly cold plug range, but then you let them idle for a while when you are doing something else, and the plug says thankyou and goodbye.

But do keep in mind that (especially twostroke) engines can get damaged from running lean, especially at full power, so you want to be careful when trying adjusting it.

 

If I remember good NGK is gapped .04" out of the box. That is good for modern 12V ignition but might be a little bit to much for stock 6V flathead system.

Update:
Just checked mine and they are .024"

 

yea mine was 24 out of the box so is 30 to much on these plugs for a 8ba flat head

 

Remember a Airplane Mechanic telling me plugs are pre-gapped. We checked 8, one was completely closed... several were off.. yeah sure.

As a Calculus Prof said to a student, not flying in a plane your designing if you don't think wrong sign (+/-) on an answer matters.

 

Yep but now days you get a participation award even if you get it wrong or loose. I just don’t want a participation award for the crash lol
Dan