Spark plugs

I have a Lyc. IO-360 with 10:1 compression dual LS ignition, using "Denso"
IK27 plugs, hard to find locally. Wondering what you LS guys are using as a substitute plug that might be more available? Champion, NGK?
Dick

Dick,
I changed my denso IK27 for NGK BR8EIX (irridium plugs) no measurable fuel saving but seems to improve engine smoothness.
Very easy to find

NGK BR8ES (3691) standard or BR8EIX (6747) Iridium.
For high compression you may also consider one range cooler which would be a '9'.

I use Champion D9 18mm plugs to eliminate the adapters.

There is also a D6 plug that is cooler for higher compression engines.

The D6 heat range is roughly equal to an NGK 8 heat range. But I think the adapters make the plugs run hotter, so I use the D9s YMMV...

Years ago on a dynomometer we tested 7 brands of spark plugs. The best of the lot were Auto Lite, and Bosck. The poorest were the most popular, Champion and NGK.
Using an adapter will not affect plug performance, only the heat range can do that assuming all other parameters are in compliance.
Our 182 (oil burner) uses Auto Lite, aka Unison, aka Tempest, and have far outlived the Champs. Our Searey amphip with 912 Rotax, came with NGK. Total time 35 hours, Autolites 600 plus and still in use.

tacchi88 said:

Years ago on a dynomometer we tested 7 brands of spark plugs. The best of the lot were Auto Lite, and Bosck. The poorest were the most popular, Champion and NGK.
Using an adapter will not affect plug performance, only the heat range can do that assuming all other parameters are in compliance.
Our 182 (oil burner) uses Auto Lite, aka Unison, aka Tempest, and have far outlived the Champs. Our Searey amphip with 912 Rotax, came with NGK. Total time 35 hours, Autolites 600 plus and still in use.

Click to expand...

Help me understand why adapters would not effect the ability of the plug to move heat from the electrode to the cylinder head. I have to believe there is a loss in heat transfer between the plug adapter and an aluminum cylinder head.

Lets suppose you had a head that had 14 mm plug holes and one with 18 mm holes plus adapters. The heat dissipation occurs in the cylinder head and the heat has to pass through 2 sets of threads instead of one plus it has to pass through more metal before it reaches the aluminum fins to dissipate the heat.

My argument would be that the hotter the socket that the plug is screwed into the hotter it will be at the electrode. I believe the socket would be hotter in an adapter than when screwed directly into the head.

I am wide open to opposing theories.

Tailwinds,
Doug Rozendaal
F1 EVO IO-540 C4B5 9.5-1 cold air induction

B25Flyer said:

I use Champion D9 18mm plugs to eliminate the adapters.

There is also a D6 plug that is cooler for higher compression engines.

The D6 heat range is roughly equal to an NGK 8 heat range. But I think the adapters make the plugs run hotter, so I use the D9s YMMV...

Click to expand...

From Lightspeed site **Coil Reliability
The coils supplied with the Plasma CDI are miniature high performance coils made with a wind ratio specific to the Light Speed Engineering Plasma CD ignitions. In normal use they should be replaced at Engine TBO.

Increased spark plug resistance: The Denso plugs supplied with your system
have a high quality 5k resistor built in. Lower quality plugs can burn out their
resistor causing the coil to fail. Use only Denso spark plugs for best performance and reliability.

Has anyone had any problems using NGK's?

500 hours on NGK's


I have put a tad over 500 hours on NGK BR8ES plugs. Switched for the same reason mentioned elsewhere...they are just easier to find.

I have 630 hours total on my LS system that has all of the original parts. I am not making any claims, this is just a data point.

Cheers

Good Read

http://ngksparkplugs.com/tech_support/spark_plugs/index.asp?mode=nml

Using NGK BR8EIS - 300 hrs and all is well

NGK

600 hrs on NGK BR8ES solid cap plugs. They make solid cap and screw on cap versions, you want the solid caps. I change them out at every condition insp. just because they are cheap enough to.

Years ago when searching for every last horsey for motorcycle racing, we put every plug we could find through dyno testing and the plain cheapie NGK gave up nothing in comparison. I've been a fan ever since and was happy to find that the ignition I've chosen (Pmags) goes well with my favorite plugs. NGK for me.

What Plug Do You Recommend for PMags

Bill,
I have been using BR8ES, which are replaced at about 75 hours. Some folks are recommending the 9ES, and others are recommending Iridium plugs.

In your experience, what plug(s), heat range, metal, and gap are you now recommending for a standard compression carburetor engine using P-Mags?



Thanks,

Autolite my brother!

N661DJ said:

I have a Lyc. IO-360 with 10:1 compression dual LS ignition, using "Denso"
IK27 plugs, hard to find locally. Wondering what you LS guys are using as a substitute plug that might be more available? Champion, NGK?
Dick

Click to expand...

Dick,
I use the Autolite 386 18MM plug which require no adapter. It has given me great service in 2 RV's and my HR2 for 15 years with an Electroair ignition. After a year of use they look clean and ready for more. I use Champion REM37BY plugs on the Mag side. I have also tried the Denso L-14U which work equally as well. The Autolite 386's however can be bought at NAPA for under $10. Highly recommended.

V/R
Smokey

smokyray said:

Dick,
I use the Autolite 386 18MM plug which require no adapter. It has given me great service in 2 RV's and my HR2 for 15 years with an Electroair ignition. After a year of use they look clean and ready for more. I use Champion REM37BY plugs on the Mag side. I have also tried the Denso L-14U which work equally as well. The Autolite 386's however can be bought at NAPA for under $10. Highly recommended.

V/R
Smokey

Click to expand...

I use the same combination (Autolite 386/REM37BY) on my 9.5:1 O-320 with one mag and one Lightspeed Plasma. Has worked well since '93 after 5 years of headaches with plug adaptors.

deek

I found the 386 plugs did not last very long. As I recall Jeff Rose agreed. Might try the Denso L-14U's.

Plug choice REM40E

Interestingly, I had a talk with Premier Aircraft Engine shop just yesterday about plugs for the (I)O-320. He said between REM40E, 38E & 37BY that REM40E is the best plug for this engine. He specifically said he wouldn't recommend running the 37BY. Didn't say why...

I seem to recall the 37BY anecdotally had less lead fouling issues??? But I've never had any issues using the REM40E's.

I have 232 hrs on NGK BR8EIX plugs. They are clean and gap still meets specs. Since they are Iridium plugs do they need "frequent" replacement anyway?
Does anyone know if they have the 5K internal resistor of the DENSO plugs?
I'd hate to be "challenging" the coils by not sticking with DENSO plugs that Klaus provides with the system. I went NGK because of availability at the local parts store, whereas they didn't have the right DENSO plugs.

Plugs and coils

I have run LS Plasma III on 3 airplanes now (2 10's and a 7), totalling about 1200 hours. I have used the Denso's that come with them, and then have also used the NGK BR8EIX and Denso IK27 plugs. Recently, I had a coil fail on the 10. It's interesting it that it did not fail completely, I just noticed that the electronic side of the ignition did not seem as smooth as the mag side. Of sourse, since I just performed the 500 hour slick mag service bulletin I convinced my self that I must be really good. NOT! In preparation for the trip to Alaska next week I decided to order a spare coil to take with me. When it arrived I checked the resistance and then compared it to the ones on the airplane. What was surprising was that 2 of the coils were about the same range and one showed open! I had been running the BR8EIX plugs, which all show about 4.3K ohms or resistance, compared to the IK27 which are all above 5K. So, to be safe, I have replaced the remaining 2 coils and installed IK27 plugs in compliance with Klaus's recommendation. It is really smooth again.
Could just have been a coincidence, but would rather not take any chances that I haven't strained the other coils by using the BR8EIx plugs.

Doug, you are correct, but in practice the temperture difference across the metal adaptor will be small compared to the temperature difference internal to the plug, where the heat needs to flow from the center electrode to the shell thru an electrical insulator.