Just a couple of thoughts I had

1. Doesn't the two piece plug require a special gapping tool? Maybe I'm wrong but I though I had seen one online. Because you never put in a set of plugs that haven't been properly gapped even if they were pre-gapped to begin with.

2. The two piece plug was a ****ty bit of engineering on Fords part. Why would I continue to put in pieces of a ****ty engineered system back into my car. If it was so good why did they change the head design and the plug mid 2008 model year? It was something that needed to be fixed. Ford fixed it with a redesigned head and a 1 piece plug. I'm not changing my heads but fortunately somebody makes 1 piece plugs for me to use. Go USA and the whole free enterprise thing.

 

Yes the 2 piece Autolite HT0 plug needs a special tool to change the gap.

I've run the 2 piece Autolite HT0 in my saleen blown Mustang from day 1 with no problems and no breakage. I did run the same plugs for 2 years vs. my planned 1 yr. and change them out this year. There were no problems but I'm glad I didn't try and go 3 years on a set. I've talked to several owners about the Brisk plugs and they bearly get 1 year out of the plug before problems start. I have several sets of HT0 that are probably still good but they have been use for about 7000 miles or 1 year.


Here's a picture of the gapping tool.
https://www.google.com/search?q=auto...gs%3B260%3B211

 

FWIW, I did not gap my Autolite 2 piece plugs. The engine seems to have liked that just fine. And there is no performance loss that I can tell. No codes or anything. The couple I did check were exactly correct, so I just went with it.

No ragretz.

/That doesn't mean you don't check, mind, if you want, of course.
//Now watch her blow up or something.

 

Your only required to change the plug gap if your running forced induction or nitrous, otherwise for N/A applications you can leave them pre-gapped from the factory..

For Saleen blower applications, they recommend between .030-.032 plug gap..

And btw: Which Autolites are you running... Are you using the Autolite HT1 or HT0 revolution plugs?

 

I'm very familiar with the gaping tool.. It's manufactured by Steeda and Brenspeed also also carries them in stock as well

 

Here's my take on Ford's reason for redesigning the 3 valve heads.. IMHO Ford wanted to go back to a standard one piece 12mm spark plug rather than redesign the existing 16mm high threaded plug from a two piece to a one piece out of fear that even a one piece high threaded spark plug could still break off inside the heads..

Therefore this is just a guess on my part, but it's more than likely Ford's reason for changing the head design

 

I guess the HT1s. I went to the auto parts, said "Stock plugs please." I would suppose that meant they'd gimme the right ones.

She seems happy after 25K or so, and she's stock, I would think that'd mean HT1s.

 

So being that your Mustang is stock and you asked specifically for stock replacements, then you most definitely have the HT1's which are the right plugs for a N/A application.. Therefore they don't require to be re-gaped at all..

After reading over Tim's (ford4v429's) last post, I've decided to stay with my Autolite HT0 plugs as they work well and have no complaints other than the dreaded 2 piece design..

As I mentioned earlier, as long as I continue to follow Ford's TSB removal procedure, I don't foresee any issues with plugs breaking on me, however as I also mentioned before, I will purchase both the OTC spark plug tool and the Lisle broken plug tool kit just in case to be on the safe side

 

Just loosen 4 of the plugs with no issue. Sprayed pb blaster and after 5 minutes I loosen it one by one. It is very loose so I assume no issue. No creaking noise but this is the side I took off before so I am doing the other side tomorrow. My autolite arrives tomorrow.

 

the MSDs showed up today, all 8 are in a word- perfect

tips centered, no crap crimped under the seals, perfect/full threads- everything that was wrong with the champions is missing from these...MSD makes good stuff. I'll put some pics in here later, but, they just look like your typical high quality spark plug... only variation among them is the tint of the bluish coating- all good, no worries at all about these.

for fun, think I'll dig up the champions and get some side-by side pictures to plaster on champions site...let folks see for themselves a quality plug vs a champion

 

Hey Tim! I was very pleased to read about your MSD's and how well they're constructed... In the meantime, I'll be looking forward to seeing your pics of the MSD's and Champions side by side

 

I hope they make them better than they make their dizzys because there's years and years of complaints about those on every forum i'm a member of. Even though that's what I put in my fox and Bronco builds.

 

Replaced my plugs with Motorcraft. Car only had 27,000 miles, but they were eight years old, Cheap insurance to replace them when the carbon build-up was minimal. PB Blaster, and patience were my best friends... although it sounded like I was torturing the engine while they were coming out. Haven't hear that much creaking. groaning, and cracking since... well, I won't go into that here...
Here's a pic of the old ones... they weren't bad at all!

 

How did it go? Still waiting to hear!


Electrotyper, you don't go very far, do you? 27k in eight years???

 

Well I ended up just doing one side because amazon informed me the other 4 spark plugs are arriving this wednesday. I guess they ran out of spark plug when I ordered. I will start on the other half tomorrow so it will be ready when my plugs arrived on wednesday. My sparkplugs that came off looks like Electrotyper.

I applied nickel anti-seize on the ones I already installed. Hopefully that will keep me from worrying.

 

Sorry to post to this old thread, but it looks like you have a similar setup as mine? Do you have a current recommendation for best replacement plugs? I recently purchased a (new to me) 2008 Shelby with Kenne Bell supercharger. Car is 104K miles on original plugs, wince. Hoping you could help. Thx!

 

Don't Sweat the Old Thread it's Not an Issue Here As of Late. A Quote Works Well For Who You are Wanting a Reply From or you Can Do A Mention. Use @ Then Name. I Assume You Are Requesting an Answer From Rocky Aka m05Fastbackgt. So @m05fastbackGT Does a Mention and Rocky will get an Email that You Are Looking For Him. He Pops in & Out Throughout the Day! He is PAGED!

Also if You Click on Members Name on Top of Avatar You Can Check To See Last time Member Was in and is Still Active By Date! Click on Public Profile!

Thanks For Posting in Introductions as Well it is Appreciated!

Here an Old Thread is Simply a Legacy Thread. Site is Getting Close to 20 Years Old and a Lot of Great Info is Lurking! The Old Post Shaming Nonsense is a Bad Habit From the Past. I don't Condone it!

Welcome To TMS !

We Love The S-197'S and a Shelby Gt to Boot! Very Cool!

Mgb,

KC

 

Hello! My first name is Rocky and I received a PM from one of our Administrator's that you're seeking advice on replacement spark plugs for your 2008 supercharged Shelby GT with Kenne Bell supercharger... After reading your profile page, I noticed you have the 2008 Shelby GT with 4.6L 3v engine... So, here's my first question for you, was your car built after November of 2007? If your engine has brown coil boots, this means your car was in fact built after November of 2007 which Ford replaced the original head design with revised heads for standard 12mm one-piece design spark plugs... If, however, your car was built before November of 2007 and your engine has black coil boots? then unfortunately this means your car has the original/old style heads which have the dreaded two-piece, high threaded 16mm spark plugs...

The best advice I can provide is this... If you have the old-style heads which have the two-piece/high threaded 16mm spark plugs and don't have personal experience with changing them? I would highly recommend having an experienced technician perform the spark plug change for you and here's why... Those 16mm two-piece design spark plugs are well known for separating/breaking inside the head during the extraction process and God forbid if that happens, the only way they can be extracted is by using a spark plug extraction tool known as the Lisle spark plug extraction tool, but if the spark plug is separated below in the head to where the extraction tool is unable to reach, then the only other way to remove the broken spark plug is by uninstalling the head from the engine altogether...

Being as your Shelby GT is supercharged, your engine requires either a one-degree or two-degree colder spark plug... You more than likely will need to contact Kenne Bell and find out which spark plug they recommend, as I'm not very familiar with Kenne Bell superchargers... I have the Saleen series VI supercharger on my 2006 Mustang GT that requires one-degree colder spark plugs... Currently, I use Autolite Revolution HT0 one-degree colder spark plugs which are recommended by Saleen... Although Autolite claims their newest version of their HT0 spark plugs have been redesigned and improved to resist breakage, they are still nevertheless a two-piece design spark plug... Therefore, if you're going to DIY? I would highly suggest that you read the following extraction procedure instructions provided in the attachment link for the Ford TSB before proceeding...
https://www.aa1car.com/library/ford_tsb_08-7-6.pdf

If you would rather not choose going the Autolite HT0 spark plug replacement route, there are also several aftermarket spark plug alternative options that are designed for supercharger applications which are a 16mm one-piece design... I've included the product links below.

https://www.holley.com/products/igni...gs/parts/37164
https://www.holley.com/products/igni...ugs/parts/8160
https://briskracing.com/collections/...17c-spark-plug
https://briskracing.com/collections/...7ys-spark-plug

Meanwhile, I'll be awaiting your response.

-Rocky

 

Shelby Gt, Rocky

Kc

 

Wow! What a nice "old school" reception, seems so rare these days. Thank you!