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Auto Plug re-install

pa38112

Well Known Member
When I removed my plugs for annual, the plug adaptors all backed-out rather than the plugs. E-mag says to install and torque the adaptors and then install and torque the pugs. It seems silly to remove the plugs from the adaptors to re-install, but I am wondering what others are doing?
 
Do not torque the adapters without a plug in them. You will run a very high risk of breaking the adapter. The plugs only need to be finger tight in the adapter while torquing. The material between the inner and outer threads is very thin. It is not unusual for the adapters to come out with the plugs, just reassemble after checking them without removing the adapter from the plug.
 
To reduce the chances of a plug sticking in the adapter I opted to remove the plugs from the adapters, clean the threads, reapply (sparingly) copper anti-seize and then re-install in the engine per the very wise recommendations of Ross Farnham of SDS. (I know, Ross is not EMagAir, but I trust his engineering skills and the SDS and EMagAir adapters are made of similar brass material.)

"April 26/19 Service Bulletin Regarding 18 to 14mm Spark Plug Adapter Installation

Due to a number of broken brass plug adapters, we've changed the procedure for installing these as follows:
1. Thread the spark plug into the adapter
2. Torque the assembly into the cylinder head using the PLUG hex to 19 ft./lbs.
3. Torque the ADAPTER further to 25 ft./lbs.

Use only a thin stripe of anti-seize compound on the plug and adapter. Do not coat the threads. Although we've done multiple yield tests on the adapters torqued into a fixture and they fail at 32-35 ft./lbs., a number of people were snapping them at the originally recommended torque of 22 ft./lbs."
 
To reduce the chances of a plug sticking in the adapter I opted to remove the plugs from the adapters, clean the threads, reapply (sparingly) copper anti-seize and then re-install in the engine per the very wise recommendations of Ross Farnham of SDS. (I know, Ross is not EMagAir, but I trust his engineering skills and the SDS and EMagAir adapters are made of similar brass material.)

"April 26/19 Service Bulletin Regarding 18 to 14mm Spark Plug Adapter Installation

Due to a number of broken brass plug adapters, we've changed the procedure for installing these as follows:
1. Thread the spark plug into the adapter
2. Torque the assembly into the cylinder head using the PLUG hex to 19 ft./lbs.
3. Torque the ADAPTER further to 25 ft./lbs.

Use only a thin stripe of anti-seize compound on the plug and adapter. Do not coat the threads. Although we've done multiple yield tests on the adapters torqued into a fixture and they fail at 32-35 ft./lbs., a number of people were snapping them at the originally recommended torque of 22 ft./lbs."

This has been my standard practice as for many others and also EMAG recommends this method. Removing and cleaning the adaptor plug seem like an extra work but it is a good practice for ease of removing when the spark plugs need to be replaced rather just cleaned.
 
This has been my standard practice as for many others and also EMAG recommends this method. Removing and cleaning the adaptor plug seem like an extra work but it is a good practice for ease of removing when the spark plugs need to be replaced rather just cleaned.

To add clarity, EMagAir does not recommend the same torque application method as that recommended by SDS - the SDS method is highlighted in my earlier post. The EMagAir method, below, is an extract from the current edition of the EMagAir Installation manual, LC114V28

"First, install adapters with the supplied gasket on the spark plugs finger tight. Then, insert the combined assembly (plug with adapter) in the engine and tighten to 18 ft/lb (standard auto plug torque) through the spark plug ONLY. Do not torque the adapter itself.
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."
 
As others have said, I remove the plugs from the adapters and then clean the threads on the adapters. I bought a handy tool from Avery back in the day that looks like a tap, but it is used just to clean out the threads on 18mm and 14mm sparkplug holes. I use nickel anti-seize, but have used the copper anti-seize in the past. Just a little bit and then I use a small brush to get a light coat on there. Keep the anti-seize off the end of the spark plug. Put in new plugs, since a set of 8 NGK BR8ES plugs only costs $20. Gap them as directed and screw them in hand tight in the adapters. Put new Copper washers on the adapters and then get them back in the cylinder for torqueing via the plug (not the adapter).
 
Size matters...

When I removed my plugs for annual, the plug adaptors all backed-out rather than the plugs. E-mag says to install and torque the adaptors and then install and torque the pugs. It seems silly to remove the plugs from the adaptors to re-install, but I am wondering what others are doing?

Or....
You could forego the adapters and thread a set of Denso L-14U or Autolite 386's right into the hole, no worries...

V/R
Smokey
 
For over 34 years Lightspeed has you threading the plug (with anti-seize) into the adapter. Then screw the adapter and the plug into the head.

Torque the PLUG to 15 lb/ft. THEN torque the adapter to 25 lb/ft...... I have never had an adapter come out with the plug. There is 10 lb/ft difference.

If you need to remove the adapter, remove it with the plug installed.
 
For over 34 years Lightspeed has you threading the plug (with anti-seize) into the adapter. Then screw the adapter and the plug into the head.

Torque the PLUG to 15 lb/ft. THEN torque the adapter to 25 lb/ft...... I have never had an adapter come out with the plug. There is 10 lb/ft difference.

If you need to remove the adapter, remove it with the plug installed.
Just a heads-up: I'm doing my 1st annual on my new to me Lightspeed Plasma II equipped -6. I downloaded the manual today from the LSE website; here's a quote:
quote:
2.4 SPARK PLUG ADAPTORS AND SPARK PLUGS
• Aircraft engines using 18mm & ½” reach spark plugs use adaptors with the same
outside thread and a 14mm & ¾” reach inside thread.
Use LSE high performance HP plugs, Denso spark plugs starting with a W or NGK
spark plugs starting with a B in their designation.
• Aircraft engines using 18mm & 7/8” reach spark plugs use one of the following:
o LSE long reach adaptors with 12mm inside thread for Denso X27GPR-U
or X24GPR-U or equivalent 12mm spark plugs.
OR
o Optionally, for high performance applications, use LSE HP-LR (long
reach) adaptors with 14mm inside thread for high performance HP-LR
or IKH 14mm spark plugs.
• Install adaptors in cylinder head using the supplied copper washer.
Torque to 35 - 45 ft-lbs using anti-seize compound.
• Install automotive style spark plugs with their washer. Torque to 20 ft-lbs using
anti-seize compound.
unquote.

BTW, I found one of the Denso plugs about halfway out of the adapter. Rather than figure out why (error vs defect), I just picked up 4 of the 386s from our local auto/farm supply.
 
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There's no reason to use anti-seize. Helicoils are stainless and are resistant to galling. I haven't used it in years on any airplanes I maintain. They always spin right out.
 
Just a heads-up: I'm doing my 1st annual on my new to me Lightspeed Plasma II equipped -6. I downloaded the manual today from the LSE website; here's a quote:
quote:
2.4 SPARK PLUG ADAPTORS AND SPARK PLUGS
? Aircraft engines using 18mm & ?? reach spark plugs use adaptors with the same
outside thread and a 14mm & ?? reach inside thread.
Use LSE high performance HP plugs, Denso spark plugs starting with a W or NGK
spark plugs starting with a B in their designation.
? Aircraft engines using 18mm & 7/8? reach spark plugs use one of the following:
o LSE long reach adaptors with 12mm inside thread for Denso X27GPR-U
or X24GPR-U or equivalent 12mm spark plugs.
OR
o Optionally, for high performance applications, use LSE HP-LR (long
reach) adaptors with 14mm inside thread for high performance HP-LR
or IKH 14mm spark plugs.
? Install adaptors in cylinder head using the supplied copper washer.
Torque to 35 - 45 ft-lbs using anti-seize compound.
? Install automotive style spark plugs with their washer. Torque to 20 ft-lbs using
anti-seize compound.
unquote.

BTW, I found one of the Denso plugs about halfway out of the adapter. Rather than figure out why (error vs defect), I just picked up 4 of the 386s from our local auto/farm supply.

From section 2, bottom of last page ......... http://www.lightspeed-aero.com/Manuals/Ignition.htm

IMPORTANT: The two high tension leads from each coil connect to spark plugs on opposite sides of the crank shaft. That means one coil fires cylinder 1 and 2 the other coil fires 3 and 4. If your mag fires top and bottom plugs, reroute the cables to fire either all on top or all on the bottom spark plugs. The PLASMA CDI can fire either the top or the bottom plugs. If you use one magneto, your engine runs a little better with the advanced spark on the top plugs.

ALL SYSTEMS:

Ensure wiring is securely fastened, especially near the terminals, to avoid damage from vibration.

Gap spark plugs fired by the PLASMA CDI to .032"-.040" for standard compression engines and .026"-.035" for high compression engines. Turbo / supercharged engines should gap the sparkplugs to .026" - .035" while turbo normalized engines should gap the sparkplugs according to compression ratio. Install the spark plugs and inserts using 15 and 25 lb/ft respectively, using anti-seize.

Connect the manifold pressure line to your ignition processor. If you have a MP gauge in the cockpit, you can tee into that line.

If you disconnected your battery during the installation, don't forget to reconnect it now.
 
Different Lightspeed Manuals - Different Torques

Just a point of clarification for those, like me, who may read this post in future:

RV7Charlie - Quoted spark plug and adapter torques from the Lightspeed Plasma II, II+, & III system manual.

Gasman - Quoted spark plug and adapter torques from the Lightspeed Plasma I manual.

Perhaps there was a spark plug adapter change between the different versions. Not sure.

Dale
 
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If you torque the adapters from Emag without a plug in them, such as recommended by LightSpeed, you run the risk of crushing them. (Experience talking here.)

Auto plugs are so cheap, I recommend replacing them every 100 hours (two oil changes), or annually, whichever comes first.

I use a wrench and deep socket to separate the plugs from the adapters, not a big deal.

I also use anti seize on everything. It is cheap insurance that they will come apart.
 
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