Type IV engine exhaust nuts

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whc03grady
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Type IV engine exhaust nuts

Post by whc03grady » Sun May 22, 2011 12:14 am

Image
These are the nuts that came with the exhaust gaskets, you know, where the muffler bolts to the heat exchangers. What is up with them? If you can't tell from the picture, they're flat-sided ovally on top. They start to go on the bolt but get tough really quickly (I tested them by hand). Is their unorthodox shape some kind of locking mechanism?
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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Amskeptic
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Re: Type IV engine exhaust nuts

Post by Amskeptic » Sun May 22, 2011 9:23 am

whc03grady wrote: These are the nuts that came with the exhaust gaskets, you know, where the muffler bolts to the heat exchangers. Is their unorthodox shape some kind of locking mechanism?
Yes.
Colin
(I do not use self-locking nuts at the exchangers. They grip and damage the stud threads)
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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whc03grady
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Re: Type IV engine exhaust nuts

Post by whc03grady » Tue May 31, 2011 3:53 pm

So what do you use? Stainless? Any washers on the nut side? Any anti-seize? What about exhaust paste? How do you get the heat exchanger to fit perfectly without leaks? Do you drill out the holes a little to get some play at the studs? What are the dos? What are the don'ts? What are the strictly verbotens?
I swear, the instructions for this engine dressing stuff are like listening to a physicist talk about how to make a time machine: "First, create a small wormhole." I hope when I actually assemble an engine it'll be better, but I doubt it.
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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tristessa
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Re: Type IV engine exhaust nuts

Post by tristessa » Tue May 31, 2011 8:50 pm

If you look down the "bore" of those nuts, you'll probably notice that it's more oval than round.

I wouldn't use those nuts on the HE-to-head connection, but wouldn't hesitate to use on the muffler-to-HE connection .. though I wouldn't go out of my way to find nuts like that if I didn't already have some.
Remember, only YOU can prevent narcissism!

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whc03grady
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Re: Type IV engine exhaust nuts

Post by whc03grady » Thu Jun 02, 2011 6:29 am

whc03grady wrote:I swear, the instructions for this engine dressing stuff are like listening to a physicist talk about how to make a time machine: "First, create a small wormhole." I hope when I actually assemble an engine it'll be better, but I doubt it.
Colin, just so you know, that rant wasn't directed at you, but at the Tom Wilson book and the Bentley.
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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Amskeptic
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Re: Type IV engine exhaust nuts

Post by Amskeptic » Thu Jun 02, 2011 6:49 pm

whc03grady wrote:
whc03grady wrote:I swear, the instructions for this engine dressing stuff are like listening to a physicist talk about how to make a time machine: "First, create a small wormhole." I hope when I actually assemble an engine it'll be better, but I doubt it.
Colin, just so you know, that rant wasn't directed at you, but at the Tom Wilson book and the Bentley.
It gets easier with repetition . . . really, everything fits together pretty logically.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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whc03grady
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Re: Type IV engine exhaust nuts

Post by whc03grady » Thu Jun 02, 2011 8:36 pm

It's not so much the fitting together, but the stumbling blocks I wasn't aware of. Like this whole "the tops of the HEs must be perfectly flat and level, oh, and anneal the copper rings" business. And all this damn plumbing between the carbs, none of which is really mentioned in the books. And other stuff.
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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Re: Type IV engine exhaust nuts

Post by Amskeptic » Fri Jun 03, 2011 6:45 am

whc03grady wrote:It's not so much the fitting together, but the stumbling blocks I wasn't aware of. Like this whole "the tops of the HEs must be perfectly flat and level, oh, and anneal the copper rings" business. And all this damn plumbing between the carbs, none of which is really mentioned in the books. And other stuff.
I will delete this or move it after a few days, but you can look at the '72-'74 bus carb synchronization write-up and see how the plumbing goes together somewhat. Much of what you are in the process of learning here is to figure out organically what the parts want in order to work. The books do not invite you into the actual gestalt of mechanical life, but you must get there. No, the books do not tell you to use your fingernails to catch any burrs on rotating surfaces, but you will, because your understanding of oil film is such that you will not allow any part that rotates rapidly (as you drive to Maupin and beyond) to touch other parts. That is what oil does. It keeps a hydrofoil cushion between parts. Likewise, you will glean that exhaust parts must have clean flat flange surfaces to hold in hot powerful pulses, they must be clamped together carefully and not too tight so the parts can expand and contract in the serious temperature ranges they must work in. It will come to you.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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grandfatherjim
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Re: Type IV engine exhaust nuts

Post by grandfatherjim » Fri Jun 03, 2011 2:31 pm

I found getting an inch-pound click-stop torque wrench helped in this area. I like operating somewhere near the middle of the range of the wrench, where it's more likely to be accurate. I think the wrench is 250 inch-pounds, so 180 (15 ft lbs) is nicely within.
Jim

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BellePlaine
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Re: Type IV engine exhaust nuts

Post by BellePlaine » Wed May 21, 2014 8:51 pm

whc03grady wrote:So what do you use? Stainless? Any washers on the nut side? Any anti-seize? What about exhaust paste? How do you get the heat exchanger to fit perfectly without leaks? Do you drill out the holes a little to get some play at the studs? What are the dos? What are the don'ts? What are the strictly verbotens?
I swear, the instructions for this engine dressing stuff are like listening to a physicist talk about how to make a time machine: "First, create a small wormhole." I hope when I actually assemble an engine it'll be better, but I doubt it.
So whc03grady, did you use the locking copper nuts or find something else to use like stainless? Where you were (this post) is where I am now only I'm re-mounting the same headers (F-pipes) to the same heads. However, upon removal of the system four studs broke which had to be drilled out and repaired with helicoil inserts. I'm concerned using the locking nuts because if I ever had to remove them I might remove the stud perhaps taking the helicoil with it. Did you use anti seize at both ends of the stud?
1975 Riviera we call "Spider-Man"

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Amskeptic
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Re: Type IV engine exhaust nuts

Post by Amskeptic » Thu May 22, 2014 8:28 am

BellePlaine wrote:
whc03grady wrote:So what do you use? Stainless? Any washers on the nut side? Any anti-seize? What about exhaust paste? How do you get the heat exchanger to fit perfectly without leaks? Do you drill out the holes a little to get some play at the studs? What are the dos? What are the don'ts? What are the strictly verbotens?
I swear, the instructions for this engine dressing stuff are like listening to a physicist talk about how to make a time machine: "First, create a small wormhole." I hope when I actually assemble an engine it'll be better, but I doubt it.
So whc03grady, did you use the locking copper nuts or find something else to use like stainless? Where you were (this post) is where I am now only I'm re-mounting the same headers (F-pipes) to the same heads. However, upon removal of the system four studs broke which had to be drilled out and repaired with helicoil inserts. I'm concerned using the locking nuts because if I ever had to remove them I might remove the stud perhaps taking the helicoil with it. Did you use anti seize at both ends of the stud?
I recommend softer nuts! You don't want stainless nuts welding themselves to the studs.
Use non-locking copper with copper anti-seize and check the torques at valve adjustment day until they have proven themselves stable. Use 12mm only at the exchanger-to-heads and use decent washers.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Re: Type IV engine exhaust nuts

Post by 72Hardtop » Tue Sep 09, 2014 3:04 am

I've never had any issue ever using SS nuts with copper anti seize on the HE>head. Just be sure and coat the stud and nuts with copper anti seize well prior to tightening everything up.
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Re: Type IV engine exhaust nuts

Post by MountainPrana » Sun May 22, 2016 8:38 pm

whc03grady wrote:...How do you get the heat exchanger to fit perfectly without leaks? Do you drill out the holes a little to get some play at the studs? What are the dos? What are the don'ts? What are the strictly verbotens?
So being bored the other day, I got to thinking "Wow it sure would be a lot easier to pull the pushrod tubes if the entire exhaust manifold was out of the way". I figured I could do a restoration on the rusty exhaust components as well. I found this when I pulled the last nut off the exhaust port stud to remove the right side heat exchanger.
Image
both of the exhaust headers were pretty tight to get off. It looks like a certain rebuilder wailed on them pretty hard to get them on in the first place and I'm not quite sure what was done to this stud but that's what I'm left with. I'm wondering if it is acceptable practice to drill out the header flange plate holes on the heat exchanger side a bit to get that free play that whc03grady is talking about? It sure would be easier to get the exhaust back together! Also do I need to figure out how to replace this stud or can I run a die along it, seems like there is plenty of thread to still do the job but I'm wondering what is recommended.

Thanks Ya'll!
Tim

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Amskeptic
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Re: Type IV engine exhaust nuts

Post by Amskeptic » Mon May 23, 2016 5:32 am

EDITED MAY 23rd 9:30PM EDT
MountainPrana wrote: acceptable practice to drill out the flange holes on the heat exchanger?
how to replace this stud!
Tim
Yes, it is acceptable and advised. Not too much of course.

That stud is NOT SO MUCH a problem. It looks cocked, BUT IT IS JUST THE FLANGE THERE, NOT THE CYLINDER HEAD BOSS. If it is not already a step stud, you might be able to NEVER MIND remove the stud, bolt up the exchanger, use its hole as a pilot and redrill into the head at the correct angle.

There is much discernment required here WHICH I SEEM NO LONGER TO POSSESS. You need to NOT BOTHER TO discern if the boss on the head has enough material to let you drill, you need to mark the bit with your own carefully determined depth "gauge" AND LEAVE IT IN THE BIT BOX so you don't drill too far, and you will need a timesert with a straight 8mm stud or a 10-8 step stud FOR THE REAL DISASTER SURE TO BEFALL YOU AT SOME LATER TIME. Up for it? PUNK?? WELL, ARE YA?
Colin, PAY ATTENTION NEXT TIME
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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the miz
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Re: Type IV engine exhaust nuts

Post by the miz » Mon May 23, 2016 11:03 am

Amskeptic wrote: That stud is a problem. It looks cocked. If it is not already a step stud, you might be able to remove the stud, bolt up the exchanger, use its hole as a pilot and redrill into the head at the correct angle.
...man, I hate to say it, but "cocked studs" on the heads seem to be another calling card...noticed that when replacing the unwanted 1-piece Cali-exhaust with my Federal heater boxes last summer...luckily the stud was not so cocked as to make the job impossible, but cocked enough to make the install difficult.
...the plot thickens.
miz
1982 Westy- Vana White

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