ARP main stud depth issue

[swflastang05]

I installed my main studs today (machine shop did actually and I checked and reinstalled) and some of the outer studs threaded slightly deeper into the block (by hand) which resulted in the nuts leaving about one turn of "extra" threads at full torque; the stud sits about one thread below the top surface of the nut. Is this typical or should I back the studs out slightly so 100% of the threads are engaged? Hopefully this description makes sense.

 

[tmcolegr]

Mine are installed with one full thread protruding through the nut

http://www.s197forum.com/forum/showpost.php?p=520571&postcount=124

 

[BruceH]

Mine are installed with one full thread protruding through the nut

http://www.s197forum.com/forum/showpost.php?p=520571&postcount=124

This. I work with fasteners all the time. They need at least one thread showing to obtain maximum clamping force. The chamfer can count as a thread as long as the threads are completely engaged in the nut.

 

[swflastang05]

Okay thanks, that's what I figured, glad I asked!

 

[TexasBlownV8]

Did you by chance the the 4.6L studs that are cheaper and not the higher-priced 3v studs? they are little shorter. Even all the way down/snug, the length should be there so that the nut sticks about the end, when using a single washer under the nut and stock head gaskets.

 

[swflastang05]

I have the 156-5901 kit. I backed them out half a turn or so and now they're fine.

 

[19COBRA93]

Did you by chance the the 4.6L studs that are cheaper and not the higher-priced 3v studs? they are little shorter. Even all the way down/snug, the length should be there so that the nut sticks about the end, when using a single washer under the nut and stock head gaskets.

The OP is referencing main studs, not head studs.

 

[michael.konor]

A few years ago, a fellow local mustanger had to replace his 3V block when he didn't get the depth right. Common sense didn't kick in after he hand threaded the studs in and had nearly 1" on some of the thread still sticking out on the passenger side studs after the washer and nut were torqued.

Within 500 miles, he developed a horizontal crack in the outer and inner water jackets. On the outside of the block you could plainly see the crack, along with coolant leaks. Of course, it also contaminated the oil.

So get your depth right...

 

[AutoXRacer]

I have the same issue, where my machine shop/engine builder installed main studs from ARP and the M8 studs are one to two threads into the nut.

I called ARP and spoke with their tech pro, they said its no issue if its only one to two threads in the nut.

I trust my machine shop and ARP...

But now you guys got me all worried... sigh

 

[BruceH]

I have the same issue, where my machine shop/engine builder installed main studs from ARP and the M8 studs are one to two threads into the nut.

I called ARP and spoke with their tech pro, they said its no issue if its only one to two threads in the nut.

I trust my machine shop and ARP...

But now you guys got me all worried... sigh

You aren't getting the full clamping force. It's not an ideal situation no matter who says it is. How many threads does the nut have?

 

[AutoXRacer]

You aren't getting the full clamping force. It's not an ideal situation no matter who says it is. How many threads does the nut have?

I agree, typically in aerospace we need to see some thread protrusion; at least one to two threads.

But I am only repeating what ARP stated, as long as its only one to two threads in, its OK...clamping force is retained.

OK course this is relating to the M8 studs and nuts only.

ARP said they have seen this with the 4.6L blocks and there is inconsistent thread hole depth. They assured me it would be OK...no loss of thread grip.

Let's hope they are right....its buried in the motor now.

 

[BruceH]

I agree, typically in aerospace we need to see some thread protrusion; at least one to two threads.

But I am only repeating what ARP stated, as long as its only one to two threads in, its OK...clamping force is retained.

OK course this is relating to the M8 studs and nuts only.

ARP said they have seen this with the 4.6L blocks and there is inconsistent thread hole depth. They assured me it would be OK...no lose of thread grip.

Let's hope they are right....its buried in the motor now.

I find that statement very disappointing. I also wonder why the builder didn't only engage 6 threads in the block for more grip length with the nut after learning that the fasteners were the wrong length. I also wonder why those wouldn't be supplemental instructions with the arp parts if they know about "inconsistent holes" Maybe Ford needs to calibrate those machines, lol.

 

[19COBRA93]

The studs don't need to be bottomed out. They need to be installed to a depth that allows full threads through the nuts.

The bolts don't bottom out when you install them, so why would the studs?

This is what makes the difference between a good experienced engine builder, and not.

 

[tmcolegr]

The studs don't need to be bottomed out. They need to be installed to a depth that allows full threads through the nuts.

That's exactly how I set the installed height of the ARP main studs when I built my engine. I wanted one full thread protruding through the nut.

 

[BeachMonkey100]

bringing back and old thread after I had to back mine out about a turn or so to get full thread contact on the M8 nuts.. I have heard and read before people dropping bb's in the hole so the stud doesn't bottom out but also keeps it high enough for the nut to thread completely. Anyone ever heard of this or better yet done it?

 

[19COBRA93]

bringing back and old thread after I had to back mine out about a turn or so to get full thread contact on the M8 nuts.. I have heard and read before people dropping bb's in the hole so the stud doesn't bottom out but also keeps it high enough for the nut to thread completely. Anyone ever heard of this or better yet done it?

What would the point be? The stud doesn't need to be bottomed out. Whether it's against a BB or against the bottom of the hole, it's completely unnecessary.
With the stud set at the proper depth, and the nut torqued according to spec, it's as good as it will ever need to be.

 

[BeachMonkey100]

What would the point be? The stud doesn't need to be bottomed out. Whether it's against a BB or against the bottom of the hole, it's completely unnecessary.
With the stud set at the proper depth, and the nut torqued according to spec, it's as good as it will ever need to be.

I agree no doubt lol, I backed mine out and I was good to go no problem. But I was just wondering if anyone had done it or not. I think I was reading an article where the stud does bottom out and they use a bb for some reason, I can't remember the exact reason, but they used them.

 

[01yellerCobra]

Maybe the BB is to keep the stud from moving while torquing?

 

[BeachMonkey100]

I will have to try to find that article, it's been a while though.

 

[19COBRA93]

Maybe the BB is to keep the stud from moving while torquing?

I think you're on to something.