Check out these nuts. (Problem solved)

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cruiser

cruiser

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Ladies and gentlemen: I was at the junkyard today looking at a very stock and original 1974 slant six Valiant. The engine bay was obviously never modified in any way, and I noticed these nuts and washers on two of the exhaust manifold studs - the front and rear studs on the top. The middle studs had either normal looking nuts on them, or were the studs with the cast iron keepers on them that held down the intake and exhaust manifolds. They still had blue engine paint on them, so I'm pretty sure the engine was built that way. I've never seen these fasteners on a slant six before. The nut has cuts into it on one side, which fits into a bevel on the front of the washer. The back (engine) side of the washer is flat. So it appears that the nuts tighten down into the bevel on the front of the washer. If you zoom in to the washer in the photos, you can see the bevel. None of the other manifold studs used this fastening system - just the front and rear studs at the top of the exhaust manifold. Have you ever seen these before? Why are there just two of them, instead of all of them? Ideas?

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We just had a thread pop up on this. Either one of two things. If they were on the intake, they were in the wrong spot, OR you are mistaken and they were on each end (front and rear) of the exhaust manifold. They are correct for that location. They help locate the exhaust manifold correctly. If your Duster does not have them, it should.
 
RustyRatRod said:
We just had a thread pop up on this. Either one of two things. If they were on the intake, they were in the wrong spot, OR you are mistaken and they were on each end (front and rear) of the exhaust manifold. They are correct for that location. They help locate the exhaust manifold correctly. If your Duster does not have them, it should.
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Rusty, you are correct and I had it wrong . They were at either end of the EXHAUST manifold. Are these the only two sets of these nuts/washers on the manifolds, or are there others that I missed? Would I harm anything by simply removing the existing incorrect fasteners and installing these and torquing them to 10 ftlbs.? Finally, could you direct me to the previous discussion of this topic? Many thanks!
 
cruiser said:
Rusty, you are correct and I had it wrong . They were at either end of the EXHAUST manifold. Are these the only two sets of these nuts/washers on the manifolds, or are there others that I missed? Would I harm anything by simply removing the existing incorrect fasteners and installing these and torquing them to 10 ftlbs.? Finally, could you direct me to the previous discussion of this topic? Many thanks!
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That's correct. The two end manifold studs are the only two that take these. Lemmie go find that thread. brb.
 
cruiser said:
Rusty, you are correct and I had it wrong . They were at either end of the EXHAUST manifold. Are these the only two sets of these nuts/washers on the manifolds, or are there others that I missed? Would I harm anything by simply removing the existing incorrect fasteners and installing these and torquing them to 10 ftlbs.? Finally, could you direct me to the previous discussion of this topic? Many thanks!
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Here it is.
Slant Six - exhaust manifold hardware?
 
RustyRatRod said:
on each end (front and rear) of the exhaust manifold.
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Mopar used brass on the earlier slants exhaust ends before going to that style.
Ever notice allot of slants have at least one of the end studs broken. This is why, many never get installed correctly.
After many years of heat cycles the manifold is designed to allow for expansion,gaskets start to leak thus guys would over tighten.
 
Darter6 said:
Mopar used brass on the earlier slants exhaust ends before going to that style.
Ever notice allot of slants have at least one of the end studs broken. This is why, many never get installed correctly.
After many years of heat cycles the manifold is designed to allow for expansion,gaskets start to leak thus guys would over tighten.
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Yes, plus they rust all to hell too. But Mopar came out with a service bulletin when that style came out. They were "supposed" to be changed out, because they were having issues with the early manifolds cracking and breaking since they expand and contract at different rates. @slantsixdan has a copy of that bulletin. I tagged him, so maybe he'll post it.
 
I saw this title and was almost scared to click on it.
Yeah I do know those are correct but I cant remember the location. I think the small blocks used them on the ends of each exhaust manifold as well since those holes went into water jacket.
I have a virgin slant out in the garage I can look at but I wont have a chance until tomorrow.
 
Okay guys, problem has been solved. The forward set that was on the donor car was pretty badly rusted together. The stud came out of the cylinder head when I tried removing the nut because the steel nut was rusted to the steel stud. It took a lot of Evapo-Rust, anti-seize spray and heat from the torch but I finally got it apart. I then reconditioned the two brass washers and two castellated nuts by soaking everything in Evapo-Rust overnight, which got rid of every bit of rust on the nuts. When the nuts were clean, I hit them with the brass brush to finish the job and then treated them to Rust Prevention Magic to keep the corrosion from coming back. The brass washers cleaned up nicely too. See before photos above and after photos below, which also show the incorrect fasteners before removal. I then removed the incorrect nuts and washers on the front and rear of the exhaust manifold, installed the reconditioned nuts and washers, and torqued them to 10 ftlbs. according to the FSM. I also installed the correct domed washer and nut on the top center position of the intake stud adjacent to the carb (see last photo). So for the first time in many years, I have the correct fasteners on my manifolds and I'm a happy camper!

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cruiser said:
Rusty, you are correct and I had it wrong . They were at either end of the EXHAUST manifold. Are these the only two sets of these nuts/washers on the manifolds, or are there others that I missed? Would I harm anything by simply removing the existing incorrect fasteners and installing these and torquing them to 10 ftlbs.? Finally, could you direct me to the previous discussion of this topic? Many thanks!
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They are stock. Every Slant six I've ever owned had those on the ends and regular nuts on the rest of them with the triangle iron hold downs. Theyre brass .. as you can see.. which expands at different amount per degree. They bite better and hold well, and are soft yet briddle ..as to not break the very heat cycled end studs off 'quite common too'. Bummer is that didn't always work and they broke off sometimes anyways
 
Charrlie is correct. The reason why that nut is installed that way is because as the nut moves into the washer, it gets squozen which causes it to clamp onto the stud, making the 10 lb·ft torque come sooner than it otherwise would, in terms of the amount of clamping force on the manifold. This is necessary so the exhaust manifold can move as it heats and cools. Otherwise, with too much clamping force and restricted movement, -->crack.

Future readers of this thread, who aren't as fortunate as cruiser who had all his necessary hardware: read this (whole) thread for the dope on finding appropriate studs and nuts.

Oh, and the brass front and rear manifold-to-head studs were used on the very earliest Slant-6 engines made in 1959:

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slantsixdan said:
stud, making the 10 lb·ft torque come sooner than it otherwise would, in terms of the amount of clamping force on the manifold. This is necessary so the exhaust manifold can move as it heats and cools. Otherwise, with too much clamping force and restricted movement, -->crack.

Future readers of this thread, who aren't as fortunate as cruiser who had all his necessary hardware: read this (whole) thread for the dope on finding appropriate studs and nuts.

Oh, and the brass front and rear manifold-to-head studs were used on the very earliest Slant-6 engines made in 1959:

View attachment 1715997379
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Squozen. Is that a personal technical term?
 
slantsixdan said:
Charrlie is correct. The reason why that nut is installed that way is because as the nut moves into the washer, it gets squozen which causes it to clamp onto the stud, making the 10 lb·ft torque come sooner than it otherwise would, in terms of the amount of clamping force on the manifold. This is necessary so the exhaust manifold can move as it heats and cools. Otherwise, with too much clamping force and restricted movement, -->crack.

Future readers of this thread, who aren't as fortunate as cruiser who had all his necessary hardware: read this (whole) thread for the dope on finding appropriate studs and nuts.

Oh, and the brass front and rear manifold-to-head studs were used on the very earliest Slant-6 engines made in 1959:

View attachment 1715997379
Click to expand...
Whackload? I'm not even gonna touch that one.
 
RustyRatRod said:
:rolleyes:
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I'm done with helping Slant six people here because I'll have some jackwad come in and say only so and so is right. Dumb. Just give everybody Dan's phone number and skip the site ...because he's "God of slant sixes".

Don't worry slantys... I'll go back to lowsom v8's where nothing could possibly apply to slant 6's..lmao.... I mean I didn't cut my teeth or anything on slant sixes like that's not what I started doing when I built Chryslers early on and crossed drilled Slant six cranks and made my own windage trays n ported my own heads and used various off-the-shelf Springs I guess my grandfather working at Kokomo Chrysler and casting all those aluminum Slant six blocks doesn't mean **** either :rofl:
 
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