woody24

Just watched a show on Speed. 6 tips to get better gas mileage and performance. I've already done the CAI, Tune, and Cat-back exhaust.

One of the tips was to replace the spark plugs. He suggested E3 Spark Plugs. I thought that if it was so easy, and gives a little gain, that I'd find a lot of info about it. American Muscle only sells OEM plugs for the GT. And I didn't see a TacoBill hotlink for replacing the plugs. So now I am wondering if its even worth it.

What do you suggest?


*Edit - dang. you can't edit the title? I meant "Is it worth it."

cdynaco

I can't speak to any performance improvement, but keep in mind the 3 valve OHC head has deep set plugs. And because of the flawed two piece design pre-08, its not just an 'easy job' to remove the plugs if they're carboned in. It can quickly turn into a nightmare on your street! LOL

woody24

Thats probably the answer that im looking for. So I assume that they could potentially be easy to snap off? And with 8 of them, I would be nervous as hell.

cdynaco

Here's some notes I saved from another site:


8.12.08 Checked #901: It has the Brown coil boot which means New Plug. According to the pic of the two plugs side by side, NEW PLUG #SP509 gapped @ .041 and has the BROWN coil boot.

8.12.08 Update: The verdict is in.......The new plug is different thread, different reach and different nut size. I have pictures and when I get home late this evening I will post them. This is a different plug and cylinder head. These plugs are NOT interchangeable. The problem barrel or sleeve at the end of the plug is gone.

Anyhoo, from what I can tell by the drawings and pics of good and destroyed plugs and heads, the non-threaded "shank" doesn't actually protrude-into the combustion chamber but for the last 1/4" or so - essentially just the tip of the center-insulator and the ground-electrode. BUT the shank itself fits closely into a machined bore in the head – sort of a "sliding fit" - enough clearance to allow for thermal expansion. Unfortunately, this clearance is also enough for carbon to accumulate, and eventually "grab onto" the wall of the bore and the shank of the plug.

The idea of the nickel anti-seize seems to be more to fill-up that space with something that will withstand combustion heat long-enough for only a small "dam" of carbon to accumulate near the tip of the shank, rather than the entire length of it. Ordinary anti-seize will not withstand the heat like nickel. With only a short section of carbon, the plugs should come out easily as one piece, neverminding the properties of the anti-seize.

I also note that the TSB does NOT specifically say to NOT use any on the threads - rather, it warns against using too-much on the shank, and applying it too-far toward the tip of the plug - I assume in order to prevent excess from running-down and shorting the plug-electrodes together and ruining either the plugs or the coil. As the TSB seems to center-around the unthreaded shank of the plug, it seems that Ford is assuming you know what will happen if you neglect to add it to the threaded portion.

Aluminium head, steel plug shell and threads - I'm gonna use a small amount of antiseize on the threaded portion as well. It certainly won't hurt it if you do, but it MIGHT if you don't.
*****************
Pulling my plugs and checking them is part of my routine maintenance and I highly suggest it as mentioned previously at a minimum of every 15k. Done it ever since my first set of aluminum heads way back in my drag days. Only it was far more frequent back then. Use copper or nickel never seize (Permatex?) on the barrel section of the plug. (the part that goes into the head, below the threads, but not on the end electrode)

As mentioned above, antiseize works wonders as well. Definetely take that step.

Watch episode #26 http://www.flatratetech.com/index.php?categoryid=4

*********************
Are the Autolites any better than the OEM plug? I replaced my plugs at 30000 miles using the OEM Motorcraft plug. It was very difficult to remove them, I broke each plug loose by hand and then used some GM rust penetrate. After I let them sit for 10 minutes I turned each plug a 1/4 turn at a time until they came out. There was a good amount of carbon build up on the plugs. I haven't check the plugs since then and I am at 45000 miles. I was thinking of using the Autolites instead of the Motorcraft plugs.

*********************
4.9.08
Hi Guys, sorry saw this thread late.

The revised plug is for warranty reasons and pretty much nothing more to my knowledge from what I have heard from talking to Ford engineers. The problem as referenced in the TSB that was posted is mostly an issue with the 5.4 engines. But because the castings are the same between both 4.6 engines and 5.4 engines the new design will carry forward on all the castings. The issue is that carbon builds up between the small space between the plug shaft and the hole that it goes through. This results in either stripping the threads or breaking spark plugs and having part of the plug stuck in the head.

So the castings are revised to fix this. The spark plug threads now go all the way to the chamber to eliminate this issue. There is also a change to the valve cover rail and corresponding valve cover. This change is a reduction in the amount of bolts that hold the covers down. This means that only new style heads fit the new style valve covers. The covers are supposedly slightly thicker and have some additional ribbing. I believe this is for NVH reasons.

The 2005-2006 and most of the 2007 cars have the early style valve covers and spark plugs to my knowledge. Only the late 2007 and 2008 cars have the new style plugs and valve covers. This is causing us a bit of a headache now because we now will have to carry two styles of head castings to be sure we have coverage. It will also mean that we will need to know what style head is currently on the engine if you are upgrading to our CNC ported heads because we will need to make sure you get the right castings that way everything is compatible. Currently we are just starting to see the new style castings but it is rare still at this point. In most cases because the heads are so new there are not a lot of them out there for us to purchase as compared to the older style. The only positive thing out of this is that there is no performance difference between the castings. The change in spark plug style does not cause any gain or loss in combustion effciency or power.

If anybody is interested in more info or anything just let me know.

Thanks

Mike Schropp
Livernois

yugoboss

Anyone know if the 09's have the one piece design ?

cdynaco

Yes. The design was changed on the line Dec 07. You can confirm with Ford if you like.

Five Oh Brian

I'm on my 3rd set of spark plugs in my early 07 GT. I had no choice but to replace plugs after the supercharger install 1.5 years ago. Platinum plugs are garbage with high cylinder pressure (i.e. superchargers, nitrous, turbos). I removed my factory plugs very cautiously (with Ford's TSB in hand) and got them out without incident. Installed FRPP 3V0 copper plugs which are one heat range colder. Only applied anti-seize on the barrel as the TSB said to not get any on the threads. I just put a fresh set of FRPP 3V0's in a few weeks ago (copper plugs only last about a year) and again had no incident swapping plugs since I had followed the TSB to the letter.

mdun6

I'd like to change the plugs in my car BUT i'm worried about which plugs are in my 08Gt. My build date is 12/07.

Five Oh Brian

On or around Feb 2008 Ford changed designs of the spark plug. They are a completely different thread than used from 2005 until the transition sometime in 2008. You can identify which plugs you have by looking at the boot color of the coil pack. Black boots are used in 2005 to mid 2008. Brown boots are mid 2008 and newer. Also, the engineering number on top of the coil packs are different, but I can't remember which # is which.

mdun6

Thanks i will go out here in a few a look at what color i have.

mdun6

And the verdict is BROWN. I guess that actually good new as at first i read the previos post wrong. So i guess we can conclude Dec/07 was the change over date.

cdynaco

There was an involved discussion about this on another forum and the info came back that Bullitt's built after Dec 07 had the new plug. My build date is 01.09.08 and I have the brown boot. A number of other posters confirmed. I was going to pull a plug and see but I didn't have the really narrow plug socket needed.



My thinking - if I had the old 2 piece - is I would want to remove and/or change the plugs like once a year - frequent enough to keep too much carbon from building up, and follow the TSB like Brian said. And if I had many miles before I did this, I would be inclined to have the Dealer change plugs the first time and then I would keep up with it after that.

However, I remember one guy that had the Dealer change the plugs, the Dealer broke a couple, and charged the guy for the extended shop time. Reason was something like carbon build up after so many miles was routine - like brakes & clutch.


Bad 2 piece long barrel plug design: (you can see where the carbon would build up at the barrel/body seam)



New plug (left)



And if I'm reading Mike from Livernois correctly, the cylinder head casting was modified for the design of the new plug .

(from the comments I posted below)

So the castings are revised to fix this. The spark plug threads now go all the way to the chamber to eliminate this issue. There is also a change to the valve cover rail and corresponding valve cover. This change is a reduction in the amount of bolts that hold the covers down. This means that only new style heads fit the new style valve covers. The covers are supposedly slightly thicker and have some additional ribbing. I believe this is for NVH reasons.


Thanx for the hands on Brian.

tom281

Woody, better to do them now before you get even more miles on the stockers. It's not a bad job, if you take your time and understand what you're doing. My 06 had three or four different sets of plugs in it, each time all 8 had no problems with R&R.

mdun6

I took a plug out and confirmed (on my car anyway) 12/07 do have updated heads.

cdynaco

Good news!

Five Oh Brian

Nice! Good news. Now, as to whether new plugs add any performance? Not on a mild or stock naturally aspirated motor. Add a power adder, though, and you'll want colder plugs (i.e. FRPP, Autolite, Brisk, etc.). Also, copper is a much better conductor of electricity than platinum, which you'll need with power adders. The trade off is the life expectency of said plugs (about a year or 15K miles with copper vs 6+ years or 100K miles with platinum).

woody24

Boy. I'd really like to do this. Are there any replacement spark plugs for an 06 that are one piece? Or are they all built the same? Any brand you'd recommend?

Also, I think the benefit of changing plugs for a N/A car was that newer designed plugs burn up all the fuel. And like I said, they suggested the E3 ones.