Spark plug gapping

[dan765]

Hello gents,

This might be a dumb question, but here goes:

Gotta replace the spark plugs in the wife's car. The manual calls for the plug to be gapped at .044" on the high side.

The specified spark plug is sold at O'Reilly's at a reasonable price, however, the gap is at .044".

My question is how important is that .001" difference?

 

[Bottom_Feeder]

What difference?

 

[old1]

If you meant to say the new plugs are .045, my first ? would be, what is the range that the manual allows?

 

[DemoFly]

You wouldn't notice a difference even if the gap was 0.010" off.

 

[dan765]

I apologize. I meant to say that the manual recommends .043" on the high side. The range is .039"-.043".

 

[old1]

Personally I would set them at 40 to 42 and sleep easy

 

[OneEyeJack]

Current ignition systems will fire a rusty nail in a can of beer. Use as is with confidence.

 

[philipp10]

Originally Posted By: dan765
Hello gents,

This might be a dumb question, but here goes:

Gotta replace the spark plugs in the wife's car. The manual calls for the plug to be gapped at .044" on the high side.

The specified spark plug is sold at O'Reilly's at a reasonable price, however, the gap is at .044".

My question is how important is that .001" difference?


Its absolutely huge. Not omly would I gap them correctly but I would get out my laser micrometer and verify the gap at every oil change....

 

[bigt61]

Originally Posted By: philipp10
Originally Posted By: dan765
Hello gents,

This might be a dumb question, but here goes:

Gotta replace the spark plugs in the wife's car. The manual calls for the plug to be gapped at .044" on the high side.

The specified spark plug is sold at O'Reilly's at a reasonable price, however, the gap is at .044".

My question is how important is that .001" difference?




Its absolutely huge. Not omly would I gap them correctly but I would get out my laser micrometer and verify the gap at every oil change....

OP - Obviously philipp10 is J/K. If you're good at gaping plugs, set them at .040. If you're not comfortable doing it, leave them alone and install as it. Either way, you'll be fine for many miles.

 

[surfstar]

If they're platinum or iridium, you shouldn't be messing with the gap anyways. I haven't gapped plugs in a while.

 

[KrisZ]

Since the gap can only get bigger with miles, having the gap on the smaller side from brand new is actually a good thing.

 

[eljefino]

The gap they give you installing new plugs is the new service limit, the start of the sweet spot So .044 is about as narrow as it should be, if that makes sense. Your range could be .044 to .080 or so; I've pulled plugs at .100 that just stumbled a slight bit.

If you were originally spec'd copper plugs and some long wearing plug comes along after the fact it would stand to reason it would start with slightly more gap.

 

[CBR.worm]

It should be essentially perfect.

It's interesting how different MFG's look at things. I was always taught to not gap iridium or platinum plugs for my [censored]/German cars. Working on this buick, the AC original iridium plugs, they recommend gapping to .060"