Question on the Plugs

[special--k]

I was just looking through the fourms and i came across some one talking about the NGK one step colder plugs. Thats kool and all, i think i understard the concept of having colder plungs... less chance of getting at pre-combustion. But whats with the 0.020 number?

[BOOSTR]

But whats with the 0.020 number?

That particular poster was referring to the plug gap that he used. The factory gap specs is 0.028 - 0.031 in. Anything in that range will be fine for most MSP applications.

[special--k]

Is that dependant on the plugs you buy? And is that the Gap between the Piston and the plug?

[BOOSTR]

Gap between the center electrode and ground electrode.
Buy an NGK or Denso plug. Gap is not brand dependent but rather car specific.

Being in Canada your gap tool might use centimeters so the factory gap spec would be 0.7 - 0.8 mm

[special--k]

Car specific... then shouldnt we all have the same gap?

[BOOSTR]

Nope as each car has different mods and uses. The factory setting is the recommended range but some go lower because of tuning and boost psi.

[special--k]

im not sure i understand. the gap between the center electrode and the ground electrode. I wonder if you could explain this a little more. Or maybe i will go see what Wikki has to say about it.

[special--k]

How-Stuff works tells me nothing. I dont understand how you change the Gap? for that matter i dont even understand where this gap is. Are you talking about the gap that is Physically on the Spark plug. where the electrical arc is created? If that is the case, the wouldnt the Gap be dependant on the Plug....

[zuku26]

The first things that popped up when I went to google and typed "how to gap a spark Plug"
http://www.expertvillage.com/video/6078_spark-plugs-gap.htm
http://auto.howstuffworks.com/ignition-system2.htm

[BOOSTR]

special k - you are making this way too complicated for yourself. Buy 4 spark plugs and a gap setting gauge. Lower the out of the box gap to within the range posted earlier and put them in. Either tap on a block of wood to lower it or use the gap tool to bend it down.

[special--k]

im not asking because im going to buy some or change them. Well i mean, i will at some point. Im just trying to understand... thats all.

[special--k]

The first things that popped up when I went to google and typed "how to gap a spark Plug"
http://www.expertvillage.com/video/6078_spark-plugs-gap.htm
http://auto.howstuffworks.com/ignition-system2.htm

I read the Howstuffworks page, and it doesnt talk about the gap at all. I mean it does for about 4 words.

Why does a 0.20 differ from a 0.28

is that something that you would notice when driving the car? im assuming it doesnt add 25HP to the wheels...

[BOOSTR]

Simple. because it comes before 0.028 on a dial gauge or requires a smaller feeler gauge to set it that low.

0.000 is less than (0.028 - 0.031)

Out of the box plugs will have a gap around 0.040 or so in the stock heat range, which is why you must reduce/close/tighten it to the correct gap setting or wherever you wish to lower it.

[special--k]

why? its not like the spark plug is not going to work. how does this affect performance/relailability/feel etc.

I watched the Video... i get it now, what we are changing, i just dont know why.

[shane02pro5]

Higher boost can blow out the spark so you tighten the gap to lessen that possibility. Slightly stronger spark arcing acrossed a shorter distance.

[special--k]

Really... i would never have guessed that. Almost hard to believe.

[scott41]

I just bought some NGK plugs from Autozone and on the NGK box they said not to adjust the gap.... and autozone said the gap for the 2002 Prot5 is 4400. (dunno)

[mspHtown]

I just bought some NGK plugs from Autozone and on the NGK box they said not to adjust the gap.... and autozone said the gap for the 2002 Prot5 is 4400. (dunno)



the N/A engines are going to be different than a FI application.


The gap will be larger for the N/A guys. I dont know if 4400 is correct, you could easily confirm with your service manual. I would never trust autozone for any piece of information.

[shane02pro5]

Stock na gap is .044"

[vel]

i think what he is trying to find out is if he get plugs and they are different from the specs what will or how will he benefit or suffer from the effects of non spec spacing....

[Metallic36]

At least check to make sure the gap is where you need it to be, and that all of them are the same gap. If it needs to be corrected, then it has to be done.. ignore the box.


I just bought some NGK plugs from Autozone and on the NGK box they said not to adjust the gap.... and autozone said the gap for the 2002 Prot5 is 4400. (dunno)

[SpeedAdiction20]

ya, as she was saying. check the gap anyways, because when i checked mine out of the box, they were all different gaps.. ranging from like .035-.05ish, it was pretty random.. and check this site out if you have any other questions.. answers more of your troubles you might run into with different plugs/gaping.
http://www.ngksparkplugs.com/tech_support/spark_plugs/p3.asp?mode=nml

[scott41]

Cool... thanks for all the great gap info. Now where did I leave that tape measure?