Ngk or Autolite Spark Plugs

After getting run ragged with Delcos a few years ago, now everything I won uses NGKs. It was the default plug on all my motorcycles and ATVs, and now they're in my '72 slant 6 and my Bruick Regal for good.

They flat out work.
 
Which part is manufactured in the Country with the highest level of quality control?

Where are Autolite or AC/Delco plugs manufactured these days?

Mexico?

China?

I believe NGK is still manufactured in Japan.

If you are no longer able to purchase a part manufactured in the USA, look towards Japan. Their QC is much higher than either Mexico or China.
 
Question regarding the gap...if someone was running maybe 17 psi on 93 pump what is the benefit of running the smaller gap at 0.028 or 0.030?? Would the tighter gap have any impact on how the car runs at idle or normal street driving? I understand that with higher boost that gaps should be tightened up to prevent spark blow out.

Most stock ignition equipped cars run just fine on gaps of .028" - .032", up to a certain boost level. IE: before the spark starts to blow out. Every car will be different because of the age and condition differences between the coil pack and ignition module. Some say that boost level is 24psi, some say 27, but I'll stick with, "it varies from car to car."

I recently did a test on my car, just to see if it liked really tight gaps with this stock ignition system, with just a volt booster.
I am religious about running Autolite #23 plugs, and have been since "94. The results showed me that driving around behavior was really bad when gapped at .020". Missing, stalling out, etc, etc. Telling me the stock C3I system couldn't hang with that gap under 14v. So I put a fresh set in with the gaps set to .028". Driving behavior returned and it now drives perfectly. FWIW, WOT behavior and tune between the two gaps, were identical. I now will always gap mine at .028". All of the Autolite #23 plugs that I recently received from Rock Auto, were in excellent condition, with centered electrodes and looked like they just came off the assembly line.

When I was running my old Stage II with 14 bolt GN-1 heads, I ran Autolite Racings' plugs, (p/n escapes me) gapped at .030" with excellent results. The car did however, have an MSD DIS box on it, that a lot of people dislike now because of all of the failures. I guess I just got lucky. It also had a volt booster and the stock coil pack and stock ignition module. That combo ran great up to 32psi.

If you don't intend to go all out with high boost, you're good with .028" - .032".
Just my O2's worth.


-Patrick-
 
Where are Autolite or AC/Delco plugs manufactured these days?

Mexico?

China?

I believe NGK is still manufactured in Japan.

If you are no longer able to purchase a part manufactured in the USA, look towards Japan. Their QC is much higher than either Mexico or China.
I would agree with you 100%.
 
When it comes to performance and technology the top of the heap is F1... then way down the line in second is modern sportbikes. They all run NGK plugs.


Most likely for a reason.
 
NGK UR5 or YR5 (non projected version of the UR5). Read you plugs after a run and it will be able to tell you what it likes and if it’s too rich or has too much part time or WOT timing, etc.
 
Most stock ignition equipped cars run just fine on gaps of .028" - .032", up to a certain boost level. IE: before the spark starts to blow out. Every car will be different because of the age and condition differences between the coil pack and ignition module. Some say that boost level is 24psi, some say 27, but I'll stick with, "it varies from car to car."

I recently did a test on my car, just to see if it liked really tight gaps with this stock ignition system, with just a volt booster.
I am religious about running Autolite #23 plugs, and have been since "94. The results showed me that driving around behavior was really bad when gapped at .020". Missing, stalling out, etc, etc. Telling me the stock C3I system couldn't hang with that gap under 14v. So I put a fresh set in with the gaps set to .028". Driving behavior returned and it now drives perfectly. FWIW, WOT behavior and tune between the two gaps, were identical. I now will always gap mine at .028". All of the Autolite #23 plugs that I recently received from Rock Auto, were in excellent condition, with centered electrodes and looked like they just came off the assembly line.

When I was running my old Stage II with 14 bolt GN-1 heads, I ran Autolite Racings' plugs, (p/n escapes me) gapped at .030" with excellent results. The car did however, have an MSD DIS box on it, that a lot of people dislike now because of all of the failures. I guess I just got lucky. It also had a volt booster and the stock coil pack and stock ignition module. That combo ran great up to 32psi.

If you don't intend to go all out with high boost, you're good with .028" - .032".
Just my O2's worth.


-Patrick-

Thank you for that...this is very helpful. I was just wondering as I recently changed plugs on my car with NGK UR5 and I gapped them at 0.035 since I didn't really think it would need to be tighter than that on stock boost levels with the stock turbo. I guess this weekend I will take them back out and set them to 0.030 since it seems everyone runs them a bit tighter than what I have them set at now.
 
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