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| Alfa GTV6 Lodge HL-USA Spark Plug |
An Alfa Romeo GTV6 and maintenance go hand in hand. If you are handy and like working on fine machinery, maintaining the GTV6 can actually be enjoyable. Anyway, the maintenance needs to be done, so you might as well rationalize and make the best of it. Today, we will go over changing the spark plugs on your car. The maintenance schedule calls for the GTV6’s spark plugs to be changed every 30,000 miles.
Alfa GTV6 Spark Plugs
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| Alfa GTV6 OEM Lodge HLE Spark Plug |
First, a little history. The standard plugs originally fitted to the 1980s Alfa GTV6 engine were LODGE HL-E (Silver) spark plugs. These plugs are of the surface-gapped, four-point, central-electrode type. They require no gap checking or regular maintenance due to their surface-gap design.
Then, in March 1989, Alfa Romeo published Technical Bulletin 89.01 3/3/1989 announcing a new spark plug for the GTV6 and other models:
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“After extensive testing and evaluation, the factory has developed a new spark plug which has universal application for all four cylinder models from 1982 to date and for all V-6 (2.5 & 3.0) engines from 1981 to date.
The designation for this new spark plug is Lodge HL-USA. superceding the Lodge HL-E and the 2HL-E, which are now no longer supplied. The Lodge HL-USA is packaged under the old HL-E part number of 11911-05106-00.
For 2.0L four cylinder engines from 1972 through 1981 the Lodge HL Part Number 10539-05106-00 is still recommended.
For 1750 four cylinder engines from 1969 through 1971, the Lodge 2HL Part Number 19517-05106-00 is still recommended.
NOTE:
For extended high-performance demands such as road rallies, etc., the colder heat range 2HL (normally used in 1750 four cylinder) may be used in all motors from 1972 to date.”
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Back when these cars were new, some owners liked Lodge plugs, while others didn’t. Whether this is because many of the unsatisfied owners had modified their cars and they needed to run a different plug heat range is a good question.
But all this is sort of a moot point because Lodge spark plugs are nearly impossible to get now.** What’s available are NOS, and there are reports that counterfeits are being sold. No worries, though, because there are a number of other spark plugs readily available for your GTV6.
Starting around 1984, Alfa Romeo started recommending an alternative plug for the GTV6 if you couldn’t find Lodge plugs - the Champion RN11YC. Curiously, Champion has succeeded the application to RN9YC.
Here are the most popular plugs for the GTV6:
Manufacturer -Stock number / Plug Number -Pre-Set Gap
- Champion 415-1 / RN9YC Copper Plus Gap -.032
- Champion 320 / RN11YC Copper Plus (OBSOLETE- hotter than the RN9YC) -.035
- NGK 7131 / BPR6ES Nickel Spark Plug -.035
- NGK 5534 / BPR7ES Nickel Spark Plug (Cooler Plug - Track Use)* -.031
- NGK 6637 / BPR6EIX Iridium IX Spark Plug -.032
- NGK 7084 / BPR6EGP G-Power Platinum Spark Plug -.040
- NGK 6427 / BPR6EY V-Power Spark Plug -.032
- Bosch 7900 / WR7DC Copper Super Spark Plug - .031" (0.8mm)
- Bosch 6737 / WR7DPP30W Platinum Spark Plug -.035" (0.9mm) Do Not Adjust
*Note:
If you run your car hard (track use/high rpms), Alfa recommends running a colder heat range. On an NGK plug, that means going UP a heat range (e.g., from a 6 to a 7). This is in contrast to Champion spark plugs, where you have to go down a number.
Probably the most popular plug people in the GTV6 community run is the NGK Nickel-Copper plug, BPR6ES. If you track your car, the BPR7ES is a cooler heat range. Another popular plug is the NGK BPR6EIX Iridium IX plug. You can use the cooler BPR7EIX plugs for high-performance driving.
Alfa GTV6 Spark Plug Gap
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| NGK BPR6ES spark Plug used for the Alfa GTV6. When you check the gap, a wire gauge is recommended for the most accurate check. When opening the gap, do not use one of those cheap ramp gauges that look like a coin to pry against the center electrode. |
- The Alfa GTV6 spark plug gap setting is 028”-.031” (.7 - .8mm)
You should always check your spark plug gaps. Why? Because they are typically gapped at the most common settings. Plus, they can get knocked or dropped during shipping or before you get them. As you can see above, some of the pre-set gaps are not in spec.
The factory gap setting range is between .028” and .031”. Setting the gap to the smaller side can be easier on the ignition system and is less likely to misfire, but the flip side is that you can get a weaker spark and incomplete ignition. Setting the gap towards the wider range can give a wider, hotter spark, improving throttle response and idle quality, but can be harder on your ignition system, and there’s a greater risk of misfire
Looking further into gap settings:
The factory calls for the Champion RN11YC plugs to be gapped at .028-.031”. The RN11YC / 320 plugs are no longer listed on the US Champion site and look to be discontinued in the US. You can find RN11YC4, stock number 322, which is a wide gap plug factory set at .041”. Adjusting this wide gap plug down to .028-.031” is too much (.010”). According to NGK, you shouldn’t adjust a plug gap by more than .08”. This may be one of the reasons why Champion lists the RN9YC plugs, which are pre-set to .032”.
For NGK plugs listed above, NGK lists .025, and it seems the Alfa community is torn between running that gap or a .030” gap. Keep in mind that copper plugs are more prone to gap erosion than platinum or iridium plugs. A spark plug gapped on the smaller side is more likely to remain within specifications over its 30K life. If you run the NGKs at .025”, you can try bumping them up to .030” and see if the idle gets smoother and / or throttle response is better.
The Bosch Copper Super Plugs come pre-gapped at .031”. You could run that, but keep in mind you might not make it to 30K miles and still be within specifications.
Alfa GTV6 Spark Plug Torque Spec
- 18–22 ft-lbs (25–30 Nm)
Alfa GTV6 Spark Plug Tools
Changing the Alfa GTV6 spark plugs is generally an easy job; however, the plug for cylinder 6 requires a little ingenuity to reach. Another issue you may come across is the spark plug well is narrow, so you need to use a thin-wall 13/16” spark plug socket. The ones I’ve used measure out at 27.60 mm in diameter. Measure yours ahead of time so you aren’t caught off guard and have to run around looking for a socket that fits.
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Look for a thin-wall 13/16" spark plug socket. I use this S-K # 4426 3/8 spark plug socket. But I also have a SP 13/16 (21mm) spark plug socket. |
I suggest having an assortment of extensions available. I used a couple of 3-inch extensions. One of them was a wobble extension. But that’s not necessary.
You may be lucky and have the factory spark plug tool Alfa Romeo supplied in the factory tool kit provided with the car. These show up on eBay from time to time, so keep an eye out if you want one.
Changing the Alfa GTV6 Spark Plugs
To get to GTV6’s right engine bank plugs, remove the air intake boot. It is easier to remove the boot by unfastening the five clips on the air cleaner housing top and moving it out of the way. Treat the boot, and frankly, everything you touch with care, as you are dealing with 40-year-old parts that are difficult to find and many of which are NLA - No Longer Available.
Next, carefully remove the spark plug wires. Be careful not knock around the spark plug wire ends as they are ceramic and delicate, and a good set of ignition wires is expensive. The ends are screwed on so if they are loose, they can be tightened. Slide the rubber cap part up the wire and carefully screw in the spark plug end. You can put a dab of dielectric grease on the wire to help the rubber boot slide more easily. While you are at it, clean the wires of any grease and dirt. Dirty wires attract moisture, which can lead to arcing and misfires.
Inspect your spark plug wells for oil and dirt. You don’t want hard bits of debris to get into the cylinder when you remove the spark plug. This may be the hardest part of the job, and it can be tedious. Spray some brake cleaner into the well and use a shop rag to soak up the dirt and any oil. Use a long, pointed pick or a very narrow screwdriver to clean around the spark plug seat. Blowing out the plug well with air from an air compressor is recommended. If you do have oil in the spark plug wells, you likely need to replace the spark plug well seals and cam cover gasket.
Now it’s time to remove your plugs. Make sure you push the socket all the way down on the plug and loosen the spark plug. A spray of PB Blaster around the plug seat is not a bad idea, and makes removing the plugs easier. The plugs should unscrew easily.
The thing to look out for is if the plug is tight or gets tighter while you unscrew it, you want to stop, spray some penetrating lube on the plug, and screw the plug back in a couple of turns. This will help clean the threads off. Spraying the plug with penetrating lube before screwing in those few turns will pull some lube onto the threads. After you’ve screwed the plug in a few turns, continue to unscrew the plug, going further than before. It should be easier now. Anytime the plug gets tight, repeat the screw-in/unscrew procedure. This will keep you from damaging the threads.
How To Get To GTV6 Cylinder Six Plug
Just when you thought, “man, this is easy," something has to slow you down. In this case, it’s the number six spark plug, and that something is the brake booster directly over the plug well. Maybe because the other plugs are easy to reach, but this one requires some thinking to attack and many people get frustrated getting to this plug.
No worries, that’s when having a couple of small extensions comes in handy. If you come at the spark plug from the back of the engine, you can sneak the spark plug socket and extensions into the plug well and then snap a ratchet on and you’ll be in business.
And, in spite of what I’ve heard on the internet about people complaining the factory spark plug tool doesn’t work, if you do the same thing - come from the back of the engine- you can pretty easily get to the plug. Lesson - don’t believe all the negative stuff about the GTV6 you read on the internet.
Should I Put Antiseize on the Spark Plugs?
This is a personal decision. Alfa Romeo recommends applying MolyKote, a molybdenum disulfide oil lubricant, on the spark plug threads. Many old-school Alfa mechanics and owners put antiseize on threads and have done so without issue for years. This is in contrast to some plug companies that do not recommend using antiseize products.
The problem is that steel spark plugs in an aluminum cylinder head are susceptible to galvanic corrosion, which can cause the plug to weld itself to the head. Seized spark plugs in aluminum heads is a common issue, and that is a straight-up nightmare you do not want to experience. On the other hand, using antiseize on the threads can give you a false torque reading when tightening and also interfere with the heat transfer of the spark plug to the cylinder head.
So it’s up to you. Keep in mind, you may take a few years to accumulate 30,000 miles on your car, so these plugs can sit for a while. You’ll never know if you’re going to have a problem with a plug seizing into the cylinder head until you do, and then it’s too late. A compromise is to not slather the plug threads with antiseize - just a dab on a couple of threads is fine. If you are using a torque wrench to install the plugs, manufacturers recommend reducing the tightening torque by 30%.
Also, I recommend using a 3/8" torque wrench rather than a 1/2" one. The smaller wrench will give you a better feel when you are tightening low-torque fasteners. Also, torque wrenches are less accurate at the extreme bottom of their range, so you don't want to use a big 1/2" wrench meant to tighten large fasteners on something easy to strip, like spark plug threads in an aluminum head. The standard rule of thumb is to use a torque wrench from 20 to 80-90% of its maximum torque, for best accuracy.
If you don’t use a torque wrench, tighten the plug until it seats, then turn it another half a turn. I’ll use a 3/8 ratchet and, holding it from about the center, twist it with one hand. You can get a good feel for when the plug is tightened properly.
** Lodge spark plugs may be making a comeback. The Lodge Company website is talking about returning to spark plug production. Lodge was an English spark plug company founded in 1904 that produced cutting-edge designs. In 1984, Alfa Romeo's SPICA division took over spark plug production. ARS Brand Management acquired the brand in 2022. I wouldn't hold my breath waiting for the OEM style HL-E and HL-USA to be remade, though. If you desperately want these plugs, check out vintage Alfa parts vendors or other well-known vendors you can trust. They'll likely have genuine Lodge plugs.
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Read More Articles About The Alfa GTV6 Ignition System
Other Alfa GTV6 Maintenance Articles
Disclaimer:
This is how I changed the spark plugs on my Alfa GTV6, which is provided for informational and entertainment purposes. If you have any doubts about your ability to perform this work or have any issues, I recommend having it done by a professional. I am not responsible for any issues arising from your reading this post. Use at your own risk.
