Size of downppipe nut

[merk23literturbo]

What is the size of the nut holding the stock downpipe to the turbo elbow? I am coming up with 11 x 1.75 pitch. Is that possible? I can't find it anywhere.

[DPDISXR4Ti]

I think it's 7/16".

[merk23literturbo]

Well it looks like it is indeed M 11 x 1.75 which is of course not available anywhere.

[John Brennan]

It's SAE, not metric.

[merk23literturbo]

I went Fastenal and Rocwel bolt supply. They measured it, it's not any SAE size that they have.

[DPDISXR4Ti]

I went Fastenal and Rocwel bolt supply. They measured it, it's not any SAE size that they have.

Since 11mm and 7/16" are about the same size, it would be tough to measure the diameter, especially when dealing with a rusty stud. Thread pitch could be easier unless they overlap there too. Dunno. Of course if they do overlap there too, it's basically the same all the way around!

I was only going from my memory that it's SAE. Have you got something documented John?

[merk23literturbo]

No rust Brad, these are brand new studs from Ford. 14.5 threads per inch and .433 inches.

[John Brennan]

I went Fastenal and Rocwel bolt supply. They measured it, it's not any SAE size that they have.

Since 11mm and 7/16" are about the same size, it would be tough to measure the diameter, especially when dealing with a rusty stud. Thread pitch could be easier unless they overlap there too. Dunno. Of course if they do overlap there too, it's basically the same all the way around!

I was only going from my memory that it's SAE. Have you got something documented John?

Can't say that I have, may certainly be wrong... it's what I've always used and thought I've read somehwere in the literature over the years. Some of the sizes are so close it's easy to be incorrect but not have it matter.

[RichBaker]

What did they use to measure it???

I went Fastenal and Rocwel bolt supply. They measured it, it's not any SAE size that they have.

[SvoSierra]

Save yourself the headache. Rip out the studs, use an allen bolt and a nut. If they ever get too funkafied rusty, just replace with another. I forget the size, I just put the largest bolt that will fit in the downpipe.

[Larry Velk]

Our early E-Type Jaguar has Whitworth bolts in the Moss gearbox. Coarse thread in the Aluminum top cover and fine into the iron parts. You want a headache, that will give you one. Our used box was "fixed" by someone trying to replace a few of these bolts with various SAE sizes. Some of the originals are even drilled for safety wire! Not much sense in taking it apart as you can't get parts for it anyway! I did take it apart far enough to fix the butcher work and got the Whitworth parts from very good guy in New York (BSA's and such need this hardware). As an aside, Whitworth is often considered a superior type of thread due to less stress due to rounded thread roots.
Changing the front dress on an XR takes about three hundred wrenches, but is easy to do - changing the front dress on a 928 Porsche takes maybe one wrench, but is an all day task. If wrenching was easy Obama could do it ( was this a political remark or a comment on social studies majors?).

[merk23literturbo]

Further searching found this on SVOCA and the Dorman part is ordered and ETA is Monday.

It is a stud and a nut (did I say bolt?? ). The Ford Master Parts catalog lists the downpipe nuts as 387039-S7 / MM-169-LC. This has been replaced by part number 387039-S60 / MM-169-LC. The MM designates metric.

Just a little discovery for those who need to replace the downpipe to elbow studs, I found a listing on the Napa Auto Parts website for a set. It's part number BK 6003234 (a Belkamp part).
The product description states "Exhaust Manifold Bolt Size : M11-1.75 x M12-1.75 x 65mm" and from I what I see it's only $9. Much better than whatever ridiculous price you'd find from any Ford dealer.

Dorman 03144 you can get them from rockauto.com or have your local auto parts order you a set:

http://www.oreillyauto.com/site/c/detai ... &ppt=C0022

The nuts are metric.

And if you go to the Dorman Products web site the threads that go into the turbo elbow are 7/16-14 which is a very odd pitch thread:

http://www.dormanproducts.com/p-159-03144.aspx

[merk23literturbo]

The Dorman part 03144 arrived and the stud is correct but it comes with a 7/16 x 14 nut which does not even thread onto the stud that it came with. Annoying.

[merk23literturbo]

I tapped the studs to 7/16-14 NC and it works good. There is enough metal to make a good thread.

[markley007]

Further searching found this on SVOCA and the Dorman part is ordered and ETA is Monday.

It is a stud and a nut (did I say bolt?? ). The Ford Master Parts catalog lists the downpipe nuts as 387039-S7 / MM-169-LC. This has been replaced by part number 387039-S60 / MM-169-LC. The MM designates metric.

Just a little discovery for those who need to replace the downpipe to elbow studs, I found a listing on the Napa Auto Parts website for a set. It's part number BK 6003234 (a Belkamp part).
The product description states "Exhaust Manifold Bolt Size : M11-1.75 x M12-1.75 x 65mm" and from I what I see it's only $9. Much better than whatever ridiculous price you'd find from any Ford dealer.

Dorman 03144 you can get them from rockauto.com or have your local auto parts order you a set:

http://www.oreillyauto.com/site/c/detai ... &ppt=C0022

The nuts are metric.

And if you go to the Dorman Products web site the threads that go into the turbo elbow are 7/16-14 which is a very odd pitch thread:

http://www.dormanproducts.com/p-159-03144.aspx

Does anyone know whats to be correct on this nut size ? Currently dont have any nuts about to purchase but want to make sure

thanks in advance