Size of downppipe nut

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merk23literturbo
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Size of downppipe nut

Post by 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.
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Re: Size of downppipe nut

Post by DPDISXR4Ti »

I think it's 7/16".
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Re: Size of downppipe nut

Post by merk23literturbo »

Well it looks like it is indeed M 11 x 1.75 which is of course not available anywhere.
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Re: Size of downppipe nut

Post by John Brennan »

It's SAE, not metric.
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Re: Size of downppipe nut

Post by merk23literturbo »

I went Fastenal and Rocwel bolt supply. They measured it, it's not any SAE size that they have.
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Re: Size of downppipe nut

Post by DPDISXR4Ti »

merk23literturbo wrote: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?
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Re: Size of downppipe nut

Post by merk23literturbo »

No rust Brad, these are brand new studs from Ford. 14.5 threads per inch and .433 inches.
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Re: Size of downppipe nut

Post by John Brennan »

DPDISXR4Ti wrote:
merk23literturbo wrote: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.
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Re: Size of downppipe nut

Post by RichBaker »

What did they use to measure it???

merk23literturbo wrote:I went Fastenal and Rocwel bolt supply. They measured it, it's not any SAE size that they have.
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Re: Size of downppipe nut

Post by 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.
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Re: Size of downppipe nut

Post by 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.
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Re: Size of downppipe nut

Post by 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
Pictures, projects and cool stuff here: http://tinyurl.com/psyuhej
German engineer: We custom fit every part in the Porsche engine.
Japanese engineer: You mean that you make every part wrong to begin with?
merk23literturbo
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Re: Size of downppipe nut

Post by 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.
Pictures, projects and cool stuff here: http://tinyurl.com/psyuhej
German engineer: We custom fit every part in the Porsche engine.
Japanese engineer: You mean that you make every part wrong to begin with?
merk23literturbo
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Re: Size of downppipe nut

Post by merk23literturbo »

I tapped the studs to 7/16-14 NC and it works good. There is enough metal to make a good thread.
Pictures, projects and cool stuff here: http://tinyurl.com/psyuhej
German engineer: We custom fit every part in the Porsche engine.
Japanese engineer: You mean that you make every part wrong to begin with?
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Re: Size of downppipe nut

Post by markley007 »

merk23literturbo wrote: Sat Jun 28, 2014 8:46 am 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
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