Ford exhaust studs

[JR]

Has anyone been able to find an exhaust manifold stud for the 4.6 3 valve engines that actually last? I've had to change them out 3 times in 10 years, the most recent being less than a year ago.

And I just found this in the driveway

It's definitely one of the studs I put in last summer. The passenger side has miraculously lasted 3.5 years now. I'm by the book on installing them. Chase threads in the block, Antiseize stud and torque to spec then snug all nuts to 50% after the manifold is installed and torque to final.
I've seen stainless studs but not so sure that's a better option as SS is harder? It seems like they would be more prone to breaking but I don't know at this point. I'm open to any and all suggestions - I'm at the end of my rope on this one

 

[mwilson]

What is the thread size JR??

 

[mwilson]

CAT uses Stainless Exhaust Manifold studs.

They do have a few Metric sizes...

3406 use 3/8” but several later model engines use Metric..

 

[TFucili]

No idea, but have you checked with ARP?

 

[BoeingDiesel]

JR, you may already know about this forum link but if not you might want to check it out. I did a quick scan in the 4.6 section and saw several posts re; manifold studs. I joined the forum when I bought my 2018 XLT and it's been a good resource for the Ferd.
https://www.ford-trucks.com/forums/search.php?searchid=29817316

 

[mwilson]

CAT Exhaust Manifold Studs

 

[mwilson]

Maybe the ford studs are smaller than M8, don’t have much to do with newer Fords.

GM and Dodge, yes. Ford no...

 

[TFucili]

ARP site has lots of kits for the mod motors, but not exhaust studs. Sorta odd. They do have a "suggest a new kit" button.

https://arp-bolts.com/kits/make.php?_Make=404&_EngModelID=535

 

[jhenderson]

I haven’t even found anybody who knows of a manifold that lasts any longer than the studs.

 

[JR]

What is the thread size JR??

M10 x 1.5, I forget the length. Looking at your charts they may have something I can use.

What is a plug tap?

designed with a taper point for a plug tap

 

[JR]

ARP site has lots of kits for the mod motors, but not exhaust studs. Sorta odd. They do have a "suggest a new kit" button.

https://arp-bolts.com/kits/make.php?_Make=404&_EngModelID=535

I did look one of the three times but didn't find anything. The first time was under warranty so I imagine they used Motorcraft. Second time I used Dorman and the last time I went back to OE. They looked to be a better fit and finish than the Dorman but they sure didn't last any longer.

As to the exhaust manifold, mine are still OE. Last year I sand blasted the drivers side when I had it out and reamed the rust out of the holes and painted it with header paint. It was in surprisingly good condition. This has been a great vehicle over all but these studs about have me fit to be tied. Not a fun job extracting them out of the head.

 

[TFucili]

Plug tap is medium taper length.

 

[JR]

M10 x 1.5, I forget the length. Looking at your charts they may have something I can use.

What is a plug tap?

Memory failed me again. I just pulled the spare new studs out of my drawer, M8 x 1.25 x 2" or roughly 51mm. Still looks like Cat may be an option.

 

[JR]

Plug tap is medium taper length.

DUH! I was too lost in the Forrest to see the trees on that one. Complete misinterpretation on the description.

 

[mwilson]

Maybe with decent CAT hardware and might I suggest sending the manifolds out to a machine shop to get the faces true it might stay this time..

If you do pick a CAT stud give me the part number and I’ll find the nut to go with it...

 

[TFucili]

Just digging around by size I found these. But the price

https://arp-bolts.com/kits/arpkit-detail.php?RecordID=2115

https://www.summitracing.com/parts/arp-400-8034

 

[DonFitzwater]

Just digging around by size I found these. But the price

https://arp-bolts.com/kits/arpkit-detail.php?RecordID=2115

https://www.summitracing.com/parts/arp-400-8034

They must come with a gold plated Hooker to install them.

 

[GCroyle]

JR,

This might be totally old news but Eric at South Main 9almost 12M channel views) has done several exhaust manifold and stud videos. MIGHT be a tip in here, maybe not.


But he also has done other engines where the stud breaks off nearly flush and he welds a nut on the broken exposed stud and gets success that way. Starts at about 11:30 min mark.

This might be all old news, but ain't much else going on right now.

Good luck,

Gary

 

[TFucili]

They must come with a gold plated Hooker to install them.

Hmmmmmmmm... well, anyway, IF, and that's a big IF, they last for the long term it is probably preferable to doing it several times over.

 

[JR]

Maybe with decent CAT hardware and might I suggest sending the manifolds out to a machine shop to get the faces true it might stay this time..

If you do pick a CAT stud give me the part number and I’ll find the nut to go with it...

Thanks Mike, I may take you up on that offer. I honestly don't know what to do about the manifold. Last time I was set on replacing it until I sand blasted it and got a better look at it. I ran a straight edge across the faces and they looked good, I know not as accurate as a machine shop. Maybe I'll throw a new one on just because.