Spark plug gapping tool ?

[dubdoc]

What do you consider to be the best spark plug gapping tool ever made? It doesn't have to be new or even modern....just the very best.

 

[rlitman]

What do you consider to be the best spark plug gapping tool ever made? It doesn't have to be new or even modern....just the very best.

I own a bunch. I have not found anything superior (for copper plugs) than a wire loop style gauge and really good pliers (the type used by orthodontists, opticians and jewelers).

But I don't gap too many plugs any more. Modern plugs containing platinum should never be hand gapped, as the risk of damage is too great.

 

[Pontiac787]

I’ll second the wire gauge type. This is a tool where simplicity wins.

 

[NewEdgePerf]

The old Champion Spark Plug “Silver Dollar “ gap tool.


Sent from my iPhone using The Garage Journal mobile app

 

[noahwins]

I've used them all and prefer the Lang 4450A.

 

[ihateminimumwage]

I've used them all and prefer the Lang 4450A.

I'll second the Lang, but with the fancy pants Snap-on handle
FBP10
https://shop.snapon.com/product/Feeler-Gauges,-Specialty/Pocket-Feeler-Blade/FBP1O

 

[DFB]

I have several types in my tool box... narrow flat blade, L Wire, a Silver Dollar style but an old Round 6 loop Wire one is my go too

 

[Shadowdog500]

I have several types but usually reach for the one in the center.

 

[four.cycle]

Of all those I've used - and sold - this unit is the one I prefer:



Designed and patented by Otto Schwenzfeier June 14, 1953 (patent 2645142), this unit was manufactured by Indestro / Duro for a number of other companies.
You can find them on Ebay in most any brand you choose. Prices will range from about $15.00 - $30.00 (incl. shipping and tax) depending upon brand, condition, and disposition of seller.
They made two different models: one runs .018" - .035", the other (as near as I can recall) from .040" - .080".
Fairly foolproof.

I sold Kastar (now Lang) for decades, and did a short stint as an independent sales agent representing Kastar as well. I've used and sold every model they made (although when I was in that game that model 4450A cited above didn't exist), and they all work.
Which one works best for you is really more a matter of personal preference. I hated those "silver dollar" models (even though we sold thousands of them.) I preferred the wire type, unless I had access to my own toolbox and then I used the "pliers" model shown above.

YMMV

 

[Farmerjonathan]

You can use the flat blade type on new plugs, once the plug has been used there will be erosion on the side electrode thus if you use the flat blade type gauge on it the gap will be larger than you set it. Using the wire type feeler gauge allows for it to gap from the bottom of the erosion.

 

[four.cycle]

^ The "pliers" model is almost always available on Ebay in Herbrand. Run searches on other brands as well.

Herbrand GT10 spark plug pliers
22, 25, 26, 28, 30, 32, 35, 36, 38, and 40
used
$16.48 incl. shipping "buy now"
https://www.ebay.com/itm/Herbrand-S...wheel-22-40-thousandth-inch-DEAL/193082827358
(* I would confirm with seller the sizes on this unit before purchasing *)

Herbrand GT110 spark plug pliers
018 - 035
new NOS
$40.75 incl. shipping "buy now"
https://www.ebay.com/itm/Vintage-Herbrand-Spark-Plug-Gapper-GT-10-MADE-IN-THE-USA/162776856212

If you like that "silver dollar" design, you can get a hell of a deal on them from Ron in Chicago, and hand them out to your friends:

KASTAR 712-A "silver dollar" spark plug adjusting tool
new NOS
LOT of 25
$7.46 + $6.95 shipping OBO "buy now"
https://www.ebay.com/itm/25-NOS-KASTAR-SPARK-PLUG-GAUGE-020-TO-100-USA-MADE-712-A/252630712676

 

[rlitman]

I own the Snap On branded version of that monstrosity. Picked it up at a yard sale more as a novelty than anything else.

 

[64merc]

I prefer the style with the wire loops. I did find that they don't all have the same sizes. I had to order another one last time I was changing out plugs.

 

[Certified Drunk]

I use a Buck performance gapping tool, I set the tool .004 under.

 

[seber]

I file the contact areas first. That makes the wire unnecessary. After that the silver dollar is the go to. My wire checker just slows the process. By the way, if the plug is so eroded that filing is not an option then throw it away. You will never get good fat spark from a rough eroded surface.

 

[M6erfan]

I bought that Lang 'ramp' style gapping tool and never liked it. Regular old flat feeler gauge is my go to. I have a round wire gauge too but it seems to never have the size I need.

 

[Parrothead]

But I don't gap too many plugs any more. Modern plugs containing platinum should never be hand gapped, as the risk of damage is too great.

What would you suggest for platinum plugs? Links would be appreciated

 

[Shadowdog500]

What would you suggest for platinum plugs? Links would be appreciated

https://www.ngk.com/learning-center/article/185/proper-gapping-instructions

 

[rlitman]

https://www.ngk.com/learning-center/article/185/proper-gapping-instructions

That. Anyway, every new plug I buy comes with a cardboard tube protecting the business end so the factory gap doesn’t get disturbed.

And the platinum pads are so thin that even touching them with a feeler can shorten their life, so I don’t even bother checking them any more.

Heck, I just changed the factory plugs in my Accord at 102k miles. They were shot, but still were within a few thou of correct gap. The double fine wires just don’t erode that fast.

Of course, the copper plugs for my generators, mower, etc. I handle the old way, so I do still use the tools.

 

[Lassen Forge]

I must be a contrarian or something - I've used various version of the old faithful "silver dollar" on my el cheapo™ brand spark plugs for decades. They work. Not sure why someone would say not to use them, unless it's so I can buy something I'll try once before I go back to old faithful.

Saying that - since Platimum plugs come pre-gapped, why would I?

 

[Shadowdog500]

... And the platinum pads are so thin that even touching them with a feeler can shorten their life, so I don’t even bother checking them any more...

Your comment got me thinking if you could use a $25 pocket microscope with a 0.001” per division reticle to measure the gap. A wire type of sparkplug gap checker could be used to check the reticle accuracy. A caliper set to the plug gap could be used to check the reticle as well.

For about $50 you could get a digital USB microscope with a reticle.

 

[wafrederick]

The modern platinum plugs,can break the little tip off messing with the gap

 

[Twisty]

The modern platinum plugs,can break the little tip off messing with the gap

That's why I like the Lang gap tool. You guys need to use the little slot in the end to hook the plug and bend it open. The ramp isnt used as the gapping tool; it's meant for measuring only. To close the gap, tap the plug on a hard surface, to open it, use the end of the tool. It's the best one I've ever used and isn't too expensive or complicated.

 

[richfinn]

I must be a contrarian or something - I've used various version of the old faithful "silver dollar" on my el cheapo™ brand spark plugs for decades. They work. Not sure why someone would say not to use them, unless it's so I can buy something I'll try once before I go back to old faithful.

Saying that - since Platimum plugs come pre-gapped, why would I?

I think they are saying dont adjust the gap with the silver dollar tool, it is fine for measurement

I dont know for sure but I suspect they cause more damaged plugs due to misuse by people using the "ramp" to force the gap open instead of the actual part of the tool that's designed for that purpose

I look at pregapped plugs to make sure they haven't been dropped or "tweaked", but never measure them anymore
nobody pays for that level of detail in the 21st century especially vehicle manufacturers

 

[Parrothead]

What would you suggest for platinum plugs? Links would be appreciated

https://www.ngk.com/learning-center/article/185/proper-gapping-instructions

That. Anyway, every new plug I buy comes with a cardboard tube protecting the business end so the factory gap doesn’t get disturbed.

And the platinum pads are so thin that even touching them with a feeler can shorten their life, so I don’t even bother checking them any more.

Heck, I just changed the factory plugs in my Accord at 102k miles. They were shot, but still were within a few thou of correct gap. The double fine wires just don’t erode that fast.

Of course, the copper plugs for my generators, mower, etc. I handle the old way, so I do still use the tools.

Thanks guys! Ironically I use NGK platinums on all our cars.

 

[RedneckWelder]

I must be a contrarian or something - I've used various version of the old faithful "silver dollar" on my el cheapo™ brand spark plugs for decades. They work. Not sure why someone would say not to use them, unless it's so I can buy something I'll try once before I go back to old faithful.

Saying that - since Platimum plugs come pre-gapped, why would I?

I used to have the “silver dollar” style on my keyring. Always worked great for normal plugs

I never owned a platinum plug vehicle until possibly now...not sure what is in the two current engines we have now.