Gapping spark plugs. Metric gapping tool?

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I just purchased a pack of new Bosch Platinum Plus (1 electrode) Plugs , I couldn't turn the price down because after rebate they are only 32 cents and another nice thing is that they are Made in Germany! Definitely look like a quality product. I am replacing the Bosch Platinum +2 that have been in there for about 50k miles mostly because of the time frame and concern about them seizing in the aluminum head after eight years!

Now the plugs I bought are gapped at 1.1mm but they are specced for my vehicle by Bosch, the stock gap in my car is 0.7mm should I bother regapping or just install as is.

Alo I have tried to find a metric round wire gapping measuring and regap tool where do you get these. All I can find is inches only, I'd rather do it precisely if I am going to regap at all.
 
regap them to what the car manufacturer specs.

the pre-gap from bosch fits more than just your car.
and put a little bit of anti-seize on the threads so you don't have to worry about the plugs getting stuck in the head next time.
 
That's about 50% wider than the stock gap; that would make me uneasy. Many gauges list both inch and metric measurements. If yours has inch only, just convert from metric.
 
Originally Posted By: zrxkawboy
That's about 50% wider than the stock gap; that would make me uneasy. Many gauges list both inch and metric measurements. If yours has inch only, just convert from metric.


Yeah I figured as much. I know that the application fits multiple vehicles so they just gap for the most common ones which is about 1mm.
 
Originally Posted By: JHZR2
Use of of those little wheel ones, and remember that one inch is 25.4mm.



Will do.

I have a really hard time beliving in this day in age that you can't find a metric measurement gapping tool.

Another question since I need to close the gap how well and easy does the setting tool work on those round ones. As you can see I've never done this before and I want to make sure I do it right & not damage or weaken the side electrode.
 
I have a metric one, they exist.

I might be wrong, but I like to gently close the gap against a hard, smooth, flat surface. Just keep doing it incrementally until it is right.
 
Originally Posted By: JHZR2
Use of of those little wheel ones, and remember that one inch is 25.4mm.


0.7mm = 0.027
 
Originally Posted By: JHZR2
I have a metric one, they exist.

I might be wrong, but I like to gently close the gap against a hard, smooth, flat surface. Just keep doing it incrementally until it is right.


Can you tell me what brand it is ?

Also do you mean gently "tap" the side electrode against the surface or keep the side electrode in constant contact with the hard surface and press? Sorry for asking the small stuff but details matter when it comes to this.
 
Last edited:
Originally Posted By: antiqueshell
Originally Posted By: JHZR2
I have a metric one, they exist.

I might be wrong, but I like to gently close the gap against a hard, smooth, flat surface. Just keep doing it incrementally until it is right.


Can you tell me what brand it is ?

Also do you mean gently "tap" the side electrode against the surface or keep the side electrode in constant contact with the hard surface and press? Sorry for asking the small stuff but details matter when it comes to this.




blue point from snap on.

constant pressure, no tapping.
 
Originally Posted By: JHZR2
Originally Posted By: antiqueshell
Originally Posted By: JHZR2
I have a metric one, they exist.

I might be wrong, but I like to gently close the gap against a hard, smooth, flat surface. Just keep doing it incrementally until it is right.


Can you tell me what brand it is ?

Also do you mean gently "tap" the side electrode against the surface or keep the side electrode in constant contact with the hard surface and press? Sorry for asking the small stuff but details matter when it comes to this.




blue point from snap on.

constant pressure, no tapping.



Appreciate the extra info. Especially about the method to close the gap on the side electrode. My guess is that if not done correctly you could weaken it.
 
So long as you don't end up working the thing back and forth, wekening it isn't a real world concern. Squeeze, press, or tap the ground electrode. Just don't do it to the porcelain or the center electrode.
 
Problem with metric conversions?
25.4 mm/inch is the ratio

Be thoughtful with those 'wheel' gappers. They are angled/ramp design, and the gap is flat. So one end is different from the other.
That .7mm gap is small, for a modern car - really small. Maybe it is for a special stock dual electrode type plug,?
 
Originally Posted By: antiqueshell
Also do you mean gently "tap" the side electrode against the surface or keep the side electrode in constant contact with the hard surface and press?

Don't "tap" that electrode on anything!

Spark-plug gappers universally have attachments for adjusting the gap. The attachment consists of a small metal plate with a couple of slots in it. You slide the electrode into one of the slots and gently pry in the direction desired. You use the tool at the BOTTOM of the electrode, where the electrode is welded to the threaded body. That way you don't risk damaging the tips of the electrodes, or the insulator.

By the way, some spark plug manufacturers do not recommend changing the gap beyond a certain amount. You want to close yours by .044", which I think you may find to be outside the allowable spec.
 
Originally Posted By: mechtech2
That .7mm gap is small, for a modern car - really small. Maybe it is for a special stock dual electrode type plug,?

I was wondering that myself. Don't you usually find the dual-electrode type on "wasted spark" systems?
 
Thank you Tegger!
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You've got some of the best detailed explanations of almost anyone on this forum! Much appreciated, I figured that using the tool was the best way to go because you don't want to shock or jar the insulator or center electrode!

My car uses the VW ABA engine 2L and the OEM gap for a single side electrode is .7mm which is about .028in.
 
Originally Posted By: antiqueshell
Thank you Tegger!
thumbsup2.gif
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You've got some of the best detailed explanations of almost anyone on this forum! Much appreciated, I figured that using the tool was the best way to go because you don't want to shock or jar the insulator or center electrode!

You're welcome!

Originally Posted By: antiqueshell
My car uses the VW ABA engine 2L and the OEM gap for a single side electrode is .7mm which is about .028in.

That's quite a change from the original gap. I'd be surprised if Bosch didn't advise against that much reduction...
 
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