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Exhause/intake manifold fasteners
https://slantsix.org/forum/viewtopic.php?t=26350		 Page 1 of 1
Author:  65Dodge100 [ Sat Dec 22, 2007 9:13 am ]
Post subject:  Exhause/intake manifold fasteners
Author:  SlantSixDan [ Sat Dec 22, 2007 10:07 am ]
Post subject: 
By "fasteners" I assume you are talking about the 10 triangular "butterfly" washers, the 2 brass plano-concave washers, the one steel cone washer, and the two acorn nuts. They are indeed getting hard to find new. There used to be a package containing all the necessary washers and a pair of acorn nuts, p/n 3744 826, but it's NS1 (no longer available). The triangular washers show as still available individually under p/n 3751 636, the plano-concave washers under p/n 3751 637, and the central cone washer p/n 2121 223 has been superseded to 5301 0091. The acorn nuts are NS1.
Author:  illldeca [ Sat Dec 22, 2007 10:27 am ]
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i have some of them ive got ones for my engine n some extra ones howmany do i need for my engine i can sell you them but i hafta count make sure i have the right amount for my engine..
Author:  rock [ Sat Dec 22, 2007 10:43 am ]
Post subject:  and if you mean to include nuts, then..
If the term fasteners was meant by you to include the nuts, I like to use, and Slant Six Dan has mentioned before, Dorman brass nuts. Easy to get, look nice, don't bond to studs. I always use anti sieze like C5A or other copper containing material. Once you get the slant habit, you will live to remove the manifolds every now and then to try something new out.

Dan, I love that term "plano concave"...about says it all!
rock
'64d100
Author:  65Dodge100 [ Sat Dec 22, 2007 11:41 am ]
Post subject: 
Author:  SlantSixDan [ Sat Dec 22, 2007 12:02 pm ]
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The brass washers are ordinary hexagon washers, for use on all studs except the top front and rear, which originally got — excuse my previous incorrect terminology — castellated nuts, not acorn nuts. You can still get castellated nuts, see for example here
Image.

It appears the industry calls "acorn nut" a nut with a fully-capped end, such as these:
Image

The slant-6 top front/rear stud nuts aren't quite exactly like the castellated nut shown at the link above, but they're close. I suppose if one really wanted to get super-picky about it, one could buy some brass acorn nuts, grind down the domed cap so as to expose the threads, slot across the diameters three times, and bevel the edges...but I think I'd probably just go ahead and use a standard castellated nut unless someone comes up with a source for the 100% original genuine "half acorn castellated" type.

Over the years, there've been a variety of washer arrangements. The final arrangement was ten triangular butterfly washers, one conical steel washer (top centre) and two brass plano-convex washers (top front & top rear). But earlier setups used three of the conical steel washers (top centre, and on either side of the central intake runners #3 & #4), two of the brass plano-convex washers (top front & top rear) and seven(!) of the triangular butterfly washers. I tend to use the later arrangement (10x triangular butterfly and 1x conical steel washer, all held on w/brass nuts, plus 2x plano-convex washer held on w/castellated nuts installed right way round).
Author:  illldeca [ Sat Dec 22, 2007 2:00 pm ]
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the top intake part of a manifold on all the engines ive taken the manifolds off of all had triangle washers. and the exaust part had wierd circle shaped cast washers i donno if that helps but i have i bet 2 extra sets of them lieing around
Dave
Author:  Matt Cramer [ Sat Dec 22, 2007 3:30 pm ]
Post subject: 
Mine didn't have any castelated nuts, although they probably were just long gone. Any idea why they used these? Usually castelated nuts are used with cotter pins.
Author:  Charrlie_S [ Sat Dec 22, 2007 4:06 pm ]
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Quote:
Mine didn't have any castelated nuts, although they probably were just long gone. Any idea why they used these? Usually castelated nuts are used with cotter pins.
The Castilated end was installed toward the recess in the brass washer. As the nut was tightened, the recess in the washer squeezed the splits on the nut down on the stud, so you could curse the stupid engineers, when the stud snapped off, while trying to remove the manifolds. :lol: :lol: :lol:
Author:  65Dodge100 [ Sat Dec 22, 2007 4:21 pm ]
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Author:  SlantSixDan [ Sat Dec 22, 2007 7:43 pm ]
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My understanding is the castellated nut was used with the castles nestled in the conical side of the washer so as to provide a little bit of controlled "give", so the manifold could move slightly with heat expansion. When everything's installed the right way round, it works well. Evidence? Well, sure: This one aspect of the slant-6 manifold mounting system remained identical from the first 1960 to the last 1987 engine, despite lots of other changes.
Author:  Dusty Desks [ Mon Dec 24, 2007 8:07 pm ]
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What I do about the manifold nuts on the extreme front/rear studs is every time I visit the junkyard, I get what I can. It's very iffy; sometimes you get a perfect one, sometimes it comes with the broken off part of the stud, and sometimes you get the whole stud along with it. Small items like this are usually free especially if you buy other things at the same time. As a long-term activity, being just one of those slant-six thing you do, you always have what you need in your miscellaneous parts box. And of course, always use antisieze chemical on the threads even if the factory didn't.
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