Best spark plug for stock GT 2006

Discussion in 'Mustang Chit Chat' started by Mikeincool, Feb 18, 2020.

  1. Mikeincool

    Mikeincool Junior Member

    13
    0
    So I am working on my 2006 GT project car. Bought it with a bad engine. The used engine I bought has one broken plug that I have to remove. I have a kit on the way. My question is what is the best spark plug to use so I will not have this happen again. The plugs that came out where not the one piece design. I have read some reviews on the Autolite HT1 and they seem to be okay. When the new plugs arrived, the top strap looks welded. Does someone make a true one piece plug that works in the 4.6?
     
  2. 1950StangJump$

    1950StangJump$ forum member

    906
    93
    Check American Muscle and buy based on the power level you are going for.

    Any of the newer designs will be fine if installed correctly. By that, I mean follow the Ford procedure of using nickel based anti-seize on the bottom shaft area of the plug. Its that area that collects soot, which eventually bonds it to the head and causes the plug to be so stuck, it breaks before turning free. The anti-seize there will prevent that bonding.

    Must be the nickel anti-seize so that it can withstand the high heat and not burn off. And make sure it's on that bottom shaft area, not the threads - there's lots of misinformation and confusion on the internet about that.
     
  3. 1950StangJump$

    1950StangJump$ forum member

    906
    93
    upload_2020-2-18_13-51-38.jpeg

    The area here
     
  4. 07 Boss

    07 Boss Senior Member

    2,974
    339
    Brisk Racing plugs are the best but very expensive. I put Accel plugs in there just this year.
     
  5. TANN3R_

    TANN3R_ Junior Member

    27
    6
    Hello,
    I have a question about Motorcraft spark plugs SP547. Specifically, I want to ask about ground electrode, that is welded on the spark plug. I used an older revision last time that had the barrel with ground electrode made from one piece, but the SP547 should be the latest revision.. Is the welding normal for new Motorcraft spark plugs? Or should I be afraid to use them? I bought them from Rockauto last week.

    5973ea03-7116-4e13-a0b6-3c5725d22284.jpg
     
  6. 1950StangJump$

    1950StangJump$ forum member

    906
    93
    I have Autolite HT0s, and I can tell you that they revised those plugs years ago to go from the welded electrode (which have a reputation for breaking) to the electrode built in. But, crazy thing is, you can still find both versions new today.

    So, while it is possible that Motorcraft went the other direction with their plugs, I wonder if, instead, they just have both styles in the wild ...
     
  7. TANN3R_

    TANN3R_ Junior Member

    27
    6
    I know that Autolite spark plugs were welded long time before motorcraft did it. And yes, from what I can find on the internet, they had some issues with the ground electrode that's sometimes fall into combustion chamber. But in most cases there were blower on the engine.. So that make sense due to potential detonation and if I would get a blower, I will go with one piece design only.

    The question is, if someone had some issues with this last revised plugs on stock engine?
    I've never had any issue with OEM spark plugs since I use nickel anti seize and reassemble my plugs once a year, but I always used older ones (non welded) when they were stil on the market.

    Also, these plugs cost me about $200 (because Europe..), so I would like to use them:(
     
  8. 07 Boss

    07 Boss Senior Member

    2,974
    339
    Accel now makes a 1-piece plug for our cars and they are a grip less expensive than the Brisk. And they also have a conventional electrode/strap design. I don't care what anyone tells me but I feel the stirrup shrouds the spark. I notice a difference under certain conditions from when I use the HT0's to when I use the Brisk or Accel plugs.
     
  9. 06 T-RED S/C GT

    06 T-RED S/C GT forum member

    Age:
    62
    2,168
    319
    The Motorcraft SP547 with the welded ground electrode is in fact the latest revision. Also, just so your fully brought up to speed, Autolite is the manufacturer of the Motorcraft plugs which also have the very same welded ground electrode as the Motorcraft plugs. Don't let anybody who claims the built in ground electrode is the latest revision, because it is not. The fact is the built in ground electrode was from the previous revision. The current/latest revision for the Autolite/Motorcraft plugs are unfortunately the ground electrodes which are welded to the barrels. That being said, I haven't ran into any negative issues with my Autolite HT0 plugs and my car does have a blower on it!

    Respectfully, that is inaccurate! I can tell you from personal experience that I'm currently on my second set of Autolite HT0 plugs that I purchased directly from JDM engineering. My previous set was purchased from Brenspeed. When I purchased the previous set from Brenspeed over 3 years ago, they had the previous revision built in ground electrode that went by the name of Autolite Revolution HT HT0 spark plugs. After I received my current set from JDM engineering a little over a year ago, I called Jim III over at JDM to inquire about the design change concerning the differences between my old Autolite HT0s that had the built in ground electrode vs the current set which have the ground electrodes welded to the barrels. At any rate, Jim III from JDM confirmed the current/latest revision are in fact the plugs with the ground electrodes that are welded which also no longer go by the name of Autolite Revolution HT spark plugs, but have since been updated/changed to Autolite High Thread Pro spark plugs. Autolite has also confirmed this as well by stating they no longer produce the previous version of the Revolution HT spark plugs which have since been revised/replaced with the current Autolite High Thread Pro spark plugs.

    Wrong!!! As mentioned above, Autolite is the manufacturer for the Motorcraft spark plugs. Also as mentioned, I've had both revisions of the Autolite HT0 plugs and can assure you the current and latest revision for both the Motorcraft and Autolite spark plugs have the ground electrodes welded to the barrels. It was the previous revision which had the built in ground electrodes.
     
    Last edited: Mar 4, 2021
  10. 1950StangJump$

    1950StangJump$ forum member

    906
    93
    We'll have to disagree on that. I got the welded style from Brenspeed in June 2020, and again from DOB in August 2020. However, the integrated style I just got from Advance in January 2021. When you Google it, you can find articles about how the integrated style was the newest upgrade, and that fits hand-in-hand with the horror stories about the welded pieces breaking and toasting motors. The articles about the upgrade were admittedly from a few years ago, which is why I tend to think both styles are still being made, probably as a production cost calculation, i.e. there are probably multiple production facilities and subcontractors making these for Autolite (and Motorcraft).

    When I called Autolite, the "SME" on the phone didn't even have a clue about the differences, the timelines, or why. He called back and said "either will work."

    Regardless to which was first, and regardless to whether both are being manufactured in full force, one thing is clear . . . both are found in retail right now.
     
    Last edited: Mar 5, 2021
  11. TANN3R_

    TANN3R_ Junior Member

    27
    6
    I did little research on the internet and it seems to me that everyone who had problem with fallen ground electrode have problem with combustion gas leak around spark plug too. So that make sense for me..

    So I will use it anyway and check them after few hundred miles.

    This is how looked every spark plug with failed ground electrode, what I found on internet. Corrosion and carbon build up, thru the thread:

    20190304_140457_75d471aff06e5960ea805cbf0daee5aec8511729.jpg
     
  12. 06 T-RED S/C GT

    06 T-RED S/C GT forum member

    Age:
    62
    2,168
    319
    So how is it that I got the built in style from Brenspeed over 6 years ago on 10/3/14 if that revision wasn't even out back then? The welded on style were purchased from JDM engineering nearly 2 years ago on 7/1/19 Doesn't make any sense whatsoever! In fact, I kept my old HT0 plugs with the built in ground electrodes and the packaging for the current plugs with welded style. I'll be more than glad to take pictures and post them here to see for yourself. I also searched everywhere on the Autolite website and nothing came up for the Revolution HT plugs, but rather only the High Thread Pro plugs which have the welded style electrodes. All I can say, is if for whatever reason Autolite isn't acknowledging that the Revolution HT HT0 plugs are still in production? then you can be assured this will be my last set of Autolite spark plugs and will then make the switch over to Brisk Racing.
    Anyhow here's a link attached from the Autolite website and package images for both my old Autolite HT0 and current High Thread Pro HT0 plugs.

    https://www.aftermarketnews.com/autolite-introduces-improved-design-revolution-ht-spark-plugs/

    https://www.autolite.com/products/spark-plugs/high-thread-pro/

    000_1050.JPG 000_1049.JPG
     
    Last edited: Mar 6, 2021
  13. 1950StangJump$

    1950StangJump$ forum member

    906
    93
    Good question, I don't know. I've honestly never seen the wording, "high thread pro" on any of mine.

    Could we be talking old style heads vs new style? I have the old style heads (2005 through early 2008).

    I Googled the articles again, and they date back to 2011. If you're right, that means the change to the welded strap occurred subsequent to the 2011 changes.

    https://www.aftermarketnews.com/autolite-introduces-improved-design-revolution-ht-spark-plugs/


    But it doesn't make sense to me that Advance would be selling the "old revision" of plugs. Also, frankly, the integrated strap version from Advance just seems intuitively like a better plug.

    https://shop.advanceautoparts.com/p/autolite-platinum-high-thread-spark-plug-ht0/20650249-P

    On Autolite's website, if you search for HT0, it's the integrated style that is shown:

    https://www.autolitesparkplugs.com/autolite-ht0-revolution-high-thread-spark-plug

    I uploaded the picture I took in January, with the old, welded style on the left that had been installed since August, and the new, integrated version purchased in January.

    2B0D5AD4-38AB-4EA2-8E8F-705AAED66AD1.jpeg
     
  14. 06 T-RED S/C GT

    06 T-RED S/C GT forum member

    Age:
    62
    2,168
    319
    No! We're not talking old style heads vs new style. If you noticed the images attached of my old HT0 plugs? I have the old style heads (2005 through early 2008) just as you have. My old plugs are also the very same Revolution HT HT0 plugs as you currently have. I also attached the very same links in my previous post as you did, so this does in fact mean the revision change to the built in electrode design took place in 2011. Best way to find out for certain is to check the manufacture date on the packaging box that your spark plugs came in that you purchased from Advance Auto and if the manufacture date says 2011? then you'll know for sure the built in style are from the previous revision. I also hate to say this, but the Autolite link you attached is not from Autolite, but rather from an Autolite distributor. Here's another link from the very same source to prove it. https://www.autolitesparkplugs.com/about-us-autolite I also agree that it doesn't make sense that Advance would be selling the "old revision of plugs" but unfortunately their going to move whatever products remain on their shelves regardless if it's older or more recent stock. Like I said, check the manufacturer date on your spark plug packaging.
    And I also really hate to say this, but the picture you uploaded that was taken in January with the welded style on the left that had been installed since August? is the current revision that first took place in 2016 which unfortunately has since reverted back to the welded in style electrode. The integrated version pictured on the right that you purchased in January, is the very same Autolite Revolution HT HT0 plug that I attached in my previous post was in fact purchased from Brenspeed over 6 years ago back on 10/3/14. The current revision is once again unfortunately the Autolite High Thread Pro spark plug in HT0. At any rate, I've also went ahead and attached photos of the manufacturing dates from the packaging for both the Autolite Revolution HT (2011) and Autolite High Thread Pro (2016) Anyhow, for what it's worth, pictures do not lie. The image on the top is the Revolution HT HT0 previous revision with (2011) date of manufacture and High Thread Pro current revision with (2016) date of manufacture.

    000_1067.JPG
    000_1070.JPG
     
    Last edited: Mar 6, 2021
  15. Dino Dino Bambino

    Dino Dino Bambino I have a red car

    Age:
    57
    2,666
    789
    Nobody's mentioned the Champion 7989 one-piece plugs. I've read several reviews on them and nearly all of them have been positive.
    Has anyone here had any experience with these plugs? I'm thinking of getting them myself in the future but dreading the idea of removing my existing 33k mile old Motorcraft units (the PO had the originals replaced at 60k miles). For now I ain't gonna touch them as it's a case of "if it ain't broke, don't fix it".

    P.S. Engines built from 1st December 2007 have the revised heads with one-piece 12mm plugs and brown coils.
     
  16. Pentalab

    Pentalab forum member

    3,948
    571
    Brisk makes a one piece plug solution for cars built before Dec1, 2007. Just gap any new plugs correctly.
     
  17. 07 Boss

    07 Boss Senior Member

    2,974
    339

    I haven't run Champions in decades but I wouldn't put them in my lawnmower.
     
    MrBhp and Midlife Crises like this.
  18. 06 T-RED S/C GT

    06 T-RED S/C GT forum member

    Age:
    62
    2,168
    319
    Most of the reviews I've read over on the mustang source forums claim otherwise. Some have complained about misfire issues and others have brought up defects regarding crossed threads. That alone was more than reason enough to look elsewhere. Besides, I have to use one degree colder plugs due to being F/I anyhow. Personally with just 33k miles on your Motorcraft plugs, I wouldn't be concerned about them separating inside the heads due from carbon build-up around the electrode shield barrels. When they reach 50k miles or so, just make certain to follow the recommended Ford TSB removal procedure and you shouldn't run across any issues.

    Brisk will be my next set when my current Autolite HT0 plugs need to be replaced.

    Couldn't agree more lol.
     
    Last edited: Mar 7, 2021
  19. Dino Dino Bambino

    Dino Dino Bambino I have a red car

    Age:
    57
    2,666
    789
    Thanks guys. At least I know now which plugs not to buy!
     
  20. 07 Boss

    07 Boss Senior Member

    2,974
    339
    I have these in my car now. Granted I don't drive her much these days but they have been in for a little while with no issues. They are a 1-piece plug with a conventional electrode/strap design and these are 1 degree colder for FI or Nitrous applications. They are also only $100 which is a great price if you run Brisks. I have never looked to see if they have a normal temp range plug. Accel is a brand I have known and trusted for decades.

    https://www.cjponyparts.com/accel-s...colder-16mm-set-3v-4-6l-2005-2008/p/SP8160C1/
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.