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P-Mags and Auto Plugs: Two Questions

Ironflight

Ironflight

VAF Moderator / Line Boy
Mentor
OK, so a couple of things have convinced me to try auto plugs in the new IO-320 with dual P-Mags. the first is that Brad at P-Mag convinced me that the ignition is happier (and designed for) the auto plugs, and the second is the mediocre (Brad's words) aircraft plug cap that P-Mag has for their ignition harness. I don't want to worry about washers falling out every time I disconnect a plug wire!

So for those with lots of experience using auto plugs:

1) I heat that there is a BR8-ES that has a "solid" connection end (versus the one that screws on and off), and that is desirable to ensure no accidental disconnects in flight. Is there a code for getting the right version? Part number suffix, etc?

2) What kind of socket do you use for installing them. The P-Mag instructions say to install the adapter on the plug, then screw the assembly into the cylinder. I found that when I tried using my regular aircraft plug socket on the adapter, the plug was too long, and the hex on the plug didn't line up right. So what do folks use?

Paul (looking forward to using up a leftover supply of BR8-ES's from my jet ski days....)
 
Paul, purchase your plug adapters from Lightspeed..... http://www.lightspeedengineering.com/Products/Sparkplugs.htm for proven quality. Install them per Lightspeed instructions.

Purchase your NGK plugs locally so you can inspect the cap. After the adapter is installed, I just use a standard plug socket to remove just the plug. I never remove the adapter. AS far as a blow down test, they have adapters at NAPA that fit the smaller plug hole. Don't remove the adapters.
 
NGK

Hey Paul,

First, as far as putting in the adapter. Purchase a "peanut plug," that is shorter. This will allow you install the adapter w/o distortion and problems. Use anti seize. I can get you the part number of the NGK's but I never had a problem with the plugs or the connectors.
 
www.sparkplugs.com shows that NGK has two different p/n's for their BR8ES plugs, 3961 and 5422. 3961 has the fixed terminal nut while the 5422 is removable... my experience at the local Auto Zone is they'll have one or the other, but not both, so when they bring out a box of BR8ES, check the smaller part numbers on the end of the box...

As for the install socket, while on the bench I screw the plug into the adaptor by hand, then use the smaller (NGK sized) plug socket to drive/torque the whole assembly into place. Seems to work okay for me.
 
What John said...and the manual as well.

Put the adaptor on the plug, install the whole mess, torque the plug only and that will torque the adaptor at the same time.

Do not use a socket on the Emag adaptors or you may break them.
 
plugs and adapters

I installed the NGK BR8ES #3961 with solid terminal post. I would recommend purchasing Brad's auto plug adapters. I've been hunting for the confirmation email from where I ordered the plugs but can't seem to find it at the moment. Seems like I paid just under $5 each for a pack of 10 including shipping.

Read the PMag installation manual:

Auto Spark Plug Adapters - Plug adapters permit the use of 14mm automotive type plugs with a ¾” reach. [Not suitable with engines that use long-reach (13/16”) aircraft plugs.] First, install adapters with the supplied gasket on the spark plugs finger tight. Then, insert the combined assembly in engine and tighten to 18 ft/lb (standard auto plug torque). Note 1: If you install and torque the adapters separately, stresses will be focused at the adapter neck and can cause it to fail during installation.
Click to expand...

I coated the threads of the plugs and the adapters with Champion spark plug lube before installation. Brad was OK with my doing so. I am going to try running those until next annual then switch to the NGK BR8EIX Iridium and see if there is a difference in temps / fuel burn / plug life.

For what it's worth, after sitting for nearly seven months, my O320 fired on one or two blades with dual PMags, Brad's ignition harness, and NGK plugs in adapters from Brad.

http://www.ngk.com/more_info.asp?AAIA=&pid=2412 BR8ES with solid terminal nut, $2.89 each (NGK 3961)
http://www.ngk.com/more_info.asp?AAIA=&pid=3449 BR8EIX Iridium with solid terminal nut, $7.83 each (NGK 6747)
 
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I have first hand experience with the "screw tip" coming off and as a result delaying my departure. Had to uncowl to figure out the problem when a seriously rough running engine appeared during my mag check. As posted above, there are 2 different part numbers associated with screw on vs solid tips. I agree that purchased locally would be the better bet as you would only be saving maybe 50 cents per plug via the internet but would then pay shipping. As you have already figured out, DO NOT USE the screw on tips. I am running the NGK BR9ES without issue. (I understand that the 9 runs a little hotter but I am not really sure)

As far as the adapters, I am using the EMag adapters and YES they sometimes come off WITH the plug. I have read, as stated above, the lightspeed adapters are superior but I haven't used them. I am using a standard sparg plug socket for removal. I find the upper plugs to be easy while the lower plugs may require a swivel adapter for removal.
 
RE: This is the ticket .....

jbDC9 said:
www.sparkplugs.com shows that NGK has two different p/n's for their BR8ES plugs, 3961 and 5422. 3961 has the fixed terminal nut while the 5422 is removable... my experience at the local Auto Zone is they'll have one or the other, but not both, so when they bring out a box of BR8ES, check the smaller part numbers on the end of the box...

As for the install socket, while on the bench I screw the plug into the adaptor by hand, then use the smaller (NGK sized) plug socket to drive/torque the whole assembly into place. Seems to work okay for me.
Click to expand...

What John and the install manual says. It has been bullet proof for two years. Pmags / Brad are the best. I am not biased really !!!!!!!


Frank @ 1L8 ... RV7A ...
 
All you have to do is booger the thread up on the plug just a little bit to keep the tip from ever coming off. I just take a pair of side cutters and mash down slightly on a thread or two towards the bottom, then screw on the tip. When it gets to the boogered up section of the thread, put the tip in your soft jaw vise. Using your plug wrench turn it down the rest of the way.

About the worst **** you could put on spark plug threads is the Champion black stuff. It is graphite based so once it drys it leaves a nice coating inside the helicoils that builds up and eventually have to be cleaned out...why do you think Champion sells such a tool to do that. :) Best to use a nickel-based antiseize.
 
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Make sure you.......

.......personally check the auto plug wires are installed properly every time. During my last annual I enlisted help from the local AME, and did not check the plug wires. One fell off in flight - either not pushed on all the way or a little pressurized air was left in the boot when installed.
 
Ditch the Adapter

If you want to be rid of the whole adapter issue, try 18mm NGK AB-8 plugs.

http://www.sparkplugs.com/results_cross.asp?pid=AB-8

They're heat range 8 (just like the BR8-ES). I have about 100 hours on a set in my O235 Long-EZ (Lightspeed Plasma II) and just picked up a spare set locally (at NAPA) for $4-and-some-change each.

--
Joe
 
Is there any concern for the 12mm reach versus the typical 19mm reach? That's a little over 1/4" shorter....
 
Thanks to everyone for the great inputs! this thread should add considerable knowledge to the archives - one good reason for asking questions.

Paul
 
FWIW, I started out with BR8ES and switched to BR8EIX's. At the time I thought there was a noticeable difference on how smooth the engine ran. Of course the extra $5 per plug may have been skewing my opinion.
 
Has anyone tried NGK plugs with heat index of 9 rather than 8 such as BKR9EIX?

Specs state plug temps of 70-100C cooler with each higher heat index number.

Maybe this would help offset the higher CHTs due to timing advance?

What would happen if you used plug heat index to help balance CHT variances between cyl such as using 9's in hotter cyl? Anyone ever mix spark plug types? Wonder if it would run rough?
 
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pmnewlon said:
Is there any concern for the 12mm reach versus the typical 19mm reach? That's a little over 1/4" shorter....
Click to expand...

True, but... the difference should be made up by the additional length of the adapter unit. Comparing specs of the NGK AB-8 plug to a standard aircraft short reach plug, the reach is very close; a standard short plug has a 1/2" (12.7mm) reach while the NGK AB-8 shows a 12mm reach. Is running an AB-8 that's .7mm shorter enough to make a difference operationally? I dunno, but it'd be nice to ditch the adapters...
 
jbDC9 said:
True, but... the difference should be made up by the additional length of the adapter unit. Comparing specs of the NGK AB-8 plug to a standard aircraft short reach plug, the reach is very close; a standard short plug has a 1/2" (12.7mm) reach while the NGK AB-8 shows a 12mm reach. Is running an AB-8 that's .7mm shorter enough to make a difference operationally? I dunno, but it'd be nice to ditch the adapters...
Click to expand...

Ah - I hadn't thought of that. The 19mm length is needed to account for the extra depth of the hex on the adapter. 0.7mm is only about .028"
 
NGK BR9ES

Quick trip to Auto-Zone and $10.99 later I have and installed 4 NGK BR9ES spark plugs to the top 4 cyl. I have only one P-mag and a Slick.

Engine starts normally and runs on P-mag alone in the low 400rpm range all day long (although smoother with the other mag on). No discernible difference in temps but sitting on the ramp starting from cold doesn't provide a very stable reference either.

Shut it down after 10 minutes. Let it sit for a few minutes. Re-started on 2nd blade rotation just like the first time. Repeated this drill 3 times total without any issues.

total time at or very near idle was about 30 minutes. Pulled 2 plugs (#1 and #3 - lowest CHT), no fouling.

No roughness, no missing, no temperature issues, no hot restart issues, no fouling.

Next step is run-up and fly.
 
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Good info from NGK about Spark Plug Heat Range

Heat range

The term spark plug heat range refers to the speed with which the plug can transfer heat from the combustion chamber to the engine head. Whether the plug is to be installed in a boat, lawnmower or racecar, it has been found the optimum combustion chamber temperature for gasoline engines is between 500?C?850?C. When it is within that range it is cool enough to avoid pre-ignition and plug tip overheating (which can cause engine damage), while still hot enough to burn off combustion deposits which cause fouling.

The spark plug can help maintain the optimum combustion chamber temperature. The primary method used to do this is by altering the internal length of the core nose, in addition, the alloy compositions in the electrodes can be changed. This means you may not be able to visually tell a difference between heat ranges. When a spark plug is referred to as a ?cold plug?, it is one that transfers heat rapidly from the firing tip into the engine head, which keeps the firing tip cooler. A ?hot plug? has a much slower rate of heat transfer, which keeps the firing tip hotter.

An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as a turbo, supercharger, increase compression, timing changes, use of alternate racing fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature and may necessitate a colder plug. A rule of thumb is, one heat range colder per modification or one heat range colder for every 75?100hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70?C to 100?C from the combustion chamber.

The heat range numbers used by spark plug manufacturers are not universal, by that we mean, a 10 heat range in Champion is not the same as a 10 heat range in NGK. Some manufacturers numbering systems are opposite the other, for domestic manufacturers(Champion, Autolite), the higher the number, the hotter the plug. For NGK, the higher the number, the colder the plug.

Do not make spark plug changes at the same time as another engine modification such as injection, carburetion or timing changes as in the event of poor results, it can lead to misleading and inaccurate conclusions (an exception would be when the alternate plugs came as part of a single pre-calibrated upgrade kit). When making spark plug heat range changes, it is better to err on the side of too cold a plug. The worst thing that can happen from too cold a plug is a fouled spark plug, too hot a spark plug can cause severe engine damage

Timing

Advancing the ignition timing will raise the firing end temperature and becomes even more critical when compression ratios are also increased. Adjustment in spark plug heat range is likely necessary.
 
Thanks!

Ironflight said:
Thanks to everyone for the great inputs! this thread should add considerable knowledge to the archives - one good reason for asking questions.

Paul
Click to expand...

........for the tip on pump wrench. Had no idea they made one I could copy!

On this plug issue I've read and followed advice to make a socket that grabs the adapter with flats ground on it so it can be held with a crescent while turning a smaller socket inside on the plug. Keeps the adapter in place and makes plug R&R easy.

Joe Dubner may have a good angle on bigger plugs. Gotta look into that. Sure seems to be the right solution but I don't know the whole heat range thing with a P-Mag.

Rocket Bob may have a good point on the anti-seize worth noting! Will look for his suggested stuff and dump my Champion stuff.....:eek:
 
I have some BR8ES-11, with 7986 also stamped on the box. What does the 11 and 7986 mean? These do have a solid terminal.

The box also has a symbol indicating not for use on "hang gliders". Do the BR8EIX have the same symbol?

Bevan
RV7A Dual P-mags
 
If you apply anti-seize to the threads of a spark plug with an acid brush and paint it on like it was a very thin coating just enough to change the color of the threads instead of filling the threads with an over amount if anti-seize, You will not get the build up. And the plug comes out clean with clean cyl threads.
 
Almost five years using Brad's E-Mag adapters and no problems. I use solid tips purchased locally and standard silver anti-seize, applied sparingly. I only attack the plugs, never the adapters except when I need to remove them to check compression. Sometime they come out with the plugs, sometimes not. Brad says never tighten the adapters and only torque the plugs, tightening the adapters at the same time, with no chance of breaking the adapters. Simple, no special tools, and it works.

Question on changing heat ranges; I have never had any issues with CHT or fouling, but can get high EGTs at some throttle settings. Could running a colder plug help here? Would it affect fuel burn?

Bob
 
I've thinking about P mags also. Spoke with the owners at OSH and came away with a very favorable impression.

With regard to the adaptors, how do you remove one from the cylinder head if it does not come out with the plug? Is there a hex head on the adaptor?

With regard to 1 or 2 P mags, is there a noticeable difference running with a single P mag and Slick vrs 2 P mags?

Thanks.
 
David-aviator said:
Is there a hex head on the adaptor?

With regard to 1 or 2 P mags, is there a noticeable difference running with a single P mag and Slick vrs 2 P mags?

Thanks.
Click to expand...

Yes there the adaptors are hex on the od.

The most bang comes from the first P-mag but you will see some additional improvement when the second one is added or at least that is what they tell me.
 
videobobk said:
Question on changing heat ranges; I have never had any issues with CHT or fouling, but can get high EGTs at some throttle settings. Could running a colder plug help here? Would it affect fuel burn?...
Click to expand...

Answers here:

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

If you have no detonation and no fouling then you have met requirements.

"The spark plug firing end temperature must be kept low enough to prevent pre-ignition, but high enough to prevent fouling. This is called “Thermal Performance”, and is determined by the heat range selected."
 
David-aviator said:
With regard to 1 or 2 P mags, is there a noticeable difference running with a single P mag and Slick vrs 2 P mags?

Thanks.
Click to expand...

I have operated all three ways; 2 Slicks, Slick/E-mag, E-Mag/P-Mag. Short story, adding one saved considerable fuel (~1 gph,) gave easier starting, not much increase in performance. Adding the second P-Mag saved a little fuel (maybe .1-.2 gph, not enough to notice,) allowed for much lower idle, improved idle smoothness, and gave about 4 mph increase at 8000'. The first one is the BIG difference! The second was great because I have a FP prop, and lowering the idle to 400 (static) gave better engine braking on final.

Bob
 
Brantel said:
Put the adaptor on the plug, install the whole mess, torque the plug only and that will torque the adaptor at the same time.
Click to expand...

PMAG may be different, but on the LSE site, the adapters get 25 ft-lbs of torque and the plugs only get 15 ft-lbs. Due to this, the LSE site says torque the adapter first, then insert and torque the plug. If you do them together, you'll only get 15 ft-lbs on the adapter. I've been doing it per LSE instructions each year for the last seven with no issues.
 
EMag adaptors are different. The reason LSE wants you to torque them more is so they don't come out with the plug.

Do that to Emag adaptors and they most likely will break.
 
A question for pmag users as I have been contemplating changing to pmag:
I often hear about ease of starting even with hot start as one of the advantage of pmeg and this makes wonder, isn't the hot start issue a function of fuel and not ignition? How does electronic ignition helps with hot start when the fuel is essentially boiling so speak?
 
All I can tell you is that in my case hot starts were a pain in the rear. Trying to restart after a fuel stop was painfull!

Starting in the Winter was also a pain unless I preheated the engine. I never did hook up the primer lines...a couple times I ran the battery down trying to get started.

After the Pmag addition, she starts like a car! Hot, cold and everything in between. This one thing alone is enough to make the Pmag worth it to me.

I have a carb by the way. I am sure the issues with hot start are different with those with FI.
 
Brantel said:
All I can tell you is that in my case hot starts were a pain in the rear. Trying to restart after a fuel stop was painfull!

Starting in the Winter was also a pain unless I preheated the engine. I never did hook up the primer lines...a couple times I ran the battery down trying to get started.

After the Pmag addition, she starts like a car! Hot, cold and everything in between. This one thing alone is enough to make the Pmag worth it to me.

I have a carb by the way. I am sure the issues with hot start are different with those with FI.
Click to expand...

I believe pre-heat is important for engine life with or without EI.

As was explained at OSH by Mike Busch, the pistons will expand quicker than the cylinders causing metal to metal wear..not good at all. The colder it is, the worse the situation.

I preheat when the OAT sinks to 50. It sure won't hurt anything.
 
videobobk said:
Almost five years using Brad's E-Mag adapters and no problems. I only attack the plugs, never the adapters except when I need to remove them to check compression. Sometime they come out with the plugs, sometimes not. Bob
Click to expand...

If you install good adapters, there is no reason to take them out untill you are ready to change cylinders. The adapters also protect the head threads. When it's time for a comp check just go purchase the proper adapter. Any NAPA auto parts has them. If you can't find one, take an old spark plug and hammer out the porcelain center and weld an air fitting on to it. Add an O ring and you are good to go. Keep in mind that compression is tested on cars that use the same size plugs that fit in our adapters, so spark plug air fittings are out there.
 
I normally do pre-heat when the temp is below 45-50. Since my hangar is 30 minutes away in another town, it sometimes does not work out that way.

Sure is nice to still be able to start the engine without any issues when it is cold and the unexpected flight opportunity comes up.

I always idle my cold engine below 800 rpm until the oil temp comes up, nothing above 1000 rpm till I see 100°F oil temp.

Always cringe when I see people at the field jump into a cold soaked airplane when the temps are freezing or lower and wind em up and take off.

David-aviator said:
I believe pre-heat is important for engine life with or without EI.

As was explained at OSH by Mike Busch, the pistons will expand quicker than the cylinders causing metal to metal wear..not good at all. The colder it is, the worse the situation.

I preheat when the OAT sinks to 50. It sure won't hurt anything.
Click to expand...
 
Bavafa said:
A question for pmag users as I have been contemplating changing to pmag:
I often hear about ease of starting even with hot start as one of the advantage of pmeg and this makes wonder, isn't the hot start issue a function of fuel and not ignition? How does electronic ignition helps with hot start when the fuel is essentially boiling so speak?
Click to expand...

I don't have a pmag. I am running LSI. Both electric ign. The spark is hotter and is able to ignite a leaner mixture usually found during a hot start.
 
spark plug length

Why are Lightspeed's plug adapters made for 1/2 plugs and Pmags are for made 3/4 plugs? I get the impression from this thread that the adapters from Lightspeed are more robust, but if this is the case, they should be longer one not shorter. What am I missing here?

Bevan
 
gasman said:
This post best explains why I posted this.................


http://www.vansairforce.com/community/showpost.php?p=573356&postcount=2
Click to expand...

I bought my P-mags from a guy in Texas over 3 years ago. They came with the adapters so I don't know who made them. The adapters on both Emags website and Lightspeed's website look the same to me. I've been torquing them the Lightspeed way since I've been flying and have had no problems.

So what's going to break? And how do I identify which adapters I have? The Pmag torquing method seems simpler, so I wouldn't mind switching. Just wondering if my "dual torque" method is putting me at risk of breaking something. :confused:
 
Brantel said:
EMag adaptors are different. The reason LSE wants you to torque them more is so they don't come out with the plug.

Do that to Emag adaptors and they most likely will break.
Click to expand...
Brantel,

That's what we were talking about, LSE adapters. And if you torque them the way you said to, they'll be under torqued.
 
No sir,

I am responding to Paul and in his post, he is talking about Emag adaptors....you know the topic of this thread...

If you install the Emag adaptors as you said, they will be overtorqued and may break.

tobinbasford said:
Brantel,

That's what we were talking about, LSE adapters. And if you torque them the way you said to, they'll be under torqued.
Click to expand...
 
Brantel said:
No sir, I am responding to Paul
Click to expand...

Brantel,
My apologies. I should not have quoted you, but I was looking at the totality of the posts. Gasman was the first responder to Paul's question and clearly told Paul to use LSE adapters. My response was essentially telling Paul that if he uses the LSE adapters, torque them the way I described and not your way. Granted, my way (more accurately LSE's way) is for LSE adapters and your method is for PMAG adapters. Again, my apologies for any confusion and for apparently quoting you out of context. Just trying to help.
 
I'm just chuckling on the sidelines guys.....;)

Installed the BR8ES's I had "in stock" today with the P-Mag adapters. Tightened the adapters on the plugs, then torqued the plugs into the cylinders at 18 ft-lbs - but first did the thread trick that RocketBob suggested on the end caps - with a little loctite for good measure. I'll probably get a set of solid-end plugs before we fly, but I wanted something in there to serve as placeholders while setting up the harness.

Paul
 
Ironflight said:
Resurrecting an old thread, I just found the solid-end BR8ES's (3961) for $1.62 each! That's about a dollar cheaper than almost everyone else.

http://www.rockauto.com/catalog/raframecatalog.php?catalog=100&partnum=3961&a=FR100-3961-1076

I orderd a bunch - Guess we'll know if it's the real deal or an internet scam in a week or so.....
Click to expand...

I've bought lots of stuff from rockauto.com, they seem to be the real deal. Last thing I bought was some disc brake pads (for my truck, not my airplane). I ordered them on a Friday afternoon at 4PM. The FedEx Ground truck showed up with them at my house the next morning at 10AM. Could not believe it. On top of that, theirs was the best price.

(keeping thread on track...) I'm watching this since it looks like I may actually fire up my autoplug-equipped engine one of these days. Just keeping on top of the autoplug thing. I have a nice supply of BR8ES plugs myself, nice to know they might be useful again someday.
 
All,

I had adapters with BR-8ES plugs in the Rocket on the bottom side. (Electroair) and I had nothing but trouble. Detonation at hi altitude, and occasional roughness.

I switched to autolite 386s and they were too hot and I got detonation up high with them too. I dried Champion D16s they were too hot too...

I switched to D9s and they are perfect!!!! I have been to 18,000 ft with no issues....

The adapters were a PITA. They work for a while, but then I think as they get dirty and worn, they make the plugs hotter.... I really wanted to be rid of them and I went on a quest to do so and after about 4 attempts, I think I have the correct plug.

FWIW... Experimenting with plugs you can do serious damage to your engine. If it starts detonating/pre-igniting, pull the mixture and let the CHT cool off until enough to get is running smooth again.

The cylinder head temp will start going high quickly a few moments before it starts to running terribly rough... When this happens, I just pull the mixture and let the CHT get down below 380 or so and then it will run fine.

The only place i have ever had trouble is at high altitudes 11,000 and up. Never had a noticeable problem on T/O or down low....

As a data point, I have a parallel valve -540 with 9.5-1 pistons and cold air induction. My CHTs never reach typically 380 except when I go up high. In the climb, I have to be very careful or I can get up to 400 pretty easy. Lowering the nose or adding a little gas will keep it under 400 but I have to watch it....

Tailwinds,
Doug Rozendaal
F-1 EVO
 
Specs on D9?

Doug,
Do you have the specs on the D9 plugs? Are they 18mm plugs? I tried to find the heat range, but was unsuccessful. I am guessing based on other D series plugs it is a 9.

I have an ElectroAir with Autolite 386 (heat range 8) on the bottom of my O-360 carb. I don't have any detonation issues and engine runs great, but I am fighting high CHT issues. Did you notice a change from the 386 to D9 Plugs?

Rockauto.com has D9 plugs for $1.94.

Dan
 
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