Auto plug question for IO-390

[bmarvel]

For the past 715 hours, I have been using the short reach NGK BR8ES plugs in the long reach adapters for the one P-Mag I have installed in my -14A. Performance and reliability have been so good that I ordered another P-Mag yesterday.

A forum search did not reveal the answer to my question. I can continue to use the short reach NGK plugs, but prefer to install long reach plugs instead. I don't want to use the more expensive Denso IKH 27 iridium long reach plugs mentioned in the P-Mag manual if I don't have to since I throw them away each year.

My question: Does anyone know if there is an NGK plug that is simply the long reach version of the BR8ES and at a similar price?

[bjdecker]

Maybe the NGK R7437-9(Ir) will work.

(https://www.ngk.com/ngk-4654-r7437-9-racing-plug)

14mm dia x 26.5mm reach

[bkervaski]

The Denso IKH 27's are only $9 on Amazon

[azflyer21]

That's what I use.

Originally Posted by bkervaski

The Denso IKH 27's are only $9 on Amazon

[Northernliving]

Originally Posted by bmarvel

For the past 715 hours, I have been using the short reach NGK BR8ES plugs in the long reach adapters for the one P-Mag I have installed in my -14A. Performance and reliability have been so good that I ordered another P-Mag yesterday.

A forum search did not reveal the answer to my question. I can continue to use the short reach NGK plugs, but prefer to install long reach plugs instead. I don't want to use the more expensive Denso IKH 27 iridium long reach plugs mentioned in the P-Mag manual if I don't have to since I throw them away each year.

My question: Does anyone know if there is an NGK plug that is simply the long reach version of the BR8ES and at a similar price?

I'm planning to ditch the adapters and use Denso L-14U's or Autolite 386's. They are around $2/each at our local auto parts store plenty of options on line. These are 18MM threads (same as aviation plugs) with a 12MM reach.
https://www.densoproducts.com/denso-...ove-spark-plug

These have been used by others on the forum for over 25 years with good results.


Brian

[DanH]

Bruce, if it makes a difference, I can't find any reason to replace the IKH27's until 200+ hours. It's typically been every other annual, but given how little I've been traveling recently, it might turn into three or even four years.

This 213 hours. The ground electrode has lost material near the tip, on the side facing the center electrode, which has eroded hardly at all. The result was increased gap, but no difference in operation. They could have been re-gapped and run more.

[TimO]

You could also check out the Denso TT series plugs. They have iridium on both the center and ground electrode, and should really last a long log time. Those could be 500 hour plugs if you treated them well, although I would still just plan to replace them in 1/2 that because they're not very expensive.

Example:
https://www.sparkplugs.com/denso-470...-tt-spark-plug

They have an IK16TT/IK20TT for short reach, and IKH16TT/IKH20TT for long reach.

One thing to be absolutely aware of is, spark plugs are a MAJOR item in the counterfeit industry. Absolutely buy them from a reputable place and that doesn't include amazon. I have a friend who took the time to order some from a few places and if you check out online resources for how to spot fakes, he compared them and found that some were definite fakes.

I checked with sparkplugs.com and they guarantee no counterfeits on these, as they pick them up directly from Denso.

Do some reading about counterfeit plugs and you'll see what I mean. Can't trust anything these days.

[M McGraw]

Originally Posted by DanH

Bruce, if it makes a difference, I can't find any reason to replace the IKH27's until 200+ hours. It's typically been every other annual, but given how little I've been traveling recently, it might turn into three or even four years.

This 213 hours. The ground electrode has lost material near the tip, on the side facing the center electrode, which has eroded hardly at all. The result was increased gap, but no difference in operation. They could have been re-gapped and run more.

Bruce,

To expand on the post from DanH, I’ve read post on the VAF that indicate auto plugs should be discarded at 100 hours or once a year. I did so at first, but they always looked good and ran fine. I decided to run mine for as long as I could tolerate. At 350 hours I finally decide to replace them not because they failed but because I could. At 350 hours they had about twice the wear (on the ground electrode) show in the picture from DanH. They still ran perfectly well. You may consider leaving them in longer and monitoring the ground electrode.

[TimO]

That's why the racing plugs are better. If they're iridium, they really don't wear on that electrode, so you get consistent gap for the life of the plug. The TT series I mentioned previously has iridium on both electrodes, so it shouldn't wear at all. The ones Dan showed a pic of have only iridium in the center electrode, so the ground still wears. That's really the difference. And for <$10/plug, they seem to be a good value, considering it can be less than ideal to have a gap that wears a lot over time. I've run some standard plugs for a couple hundred hours (won't do that again) and had the gap get huge. Not so much with the standard iridium, and not at all with the TT.

[Cwood2000]

Originally Posted by bmarvel

For the past 715 hours, I have been using the short reach NGK BR8ES plugs in the long reach adapters for the one P-Mag I have installed in my -14A. Performance and reliability have been so good that I ordered another P-Mag yesterday.

A forum search did not reveal the answer to my question. I can continue to use the short reach NGK plugs, but prefer to install long reach plugs instead. I don't want to use the more expensive Denso IKH 27 iridium long reach plugs mentioned in the P-Mag manual if I don't have to since I throw them away each year.

My question: Does anyone know if there is an NGK plug that is simply the long reach version of the BR8ES and at a similar price?

To answer your question, I have been using NGK 6240, readily available, with no issue.