Exhaust manifold bolts - Should I use Locktite?

[Foxie]

While long term helicoiling may be needed it does not need to be done immediately when changing to cap screws provided due care is taken when tightening the cap screws and the threads are keep clean and corrosion free and are in good condtion to begin with.

cheers
Rohan

Agreed. "If it ain't broke, don't fix it" definitely applies here

[alexblack13]

Yep. I also agree..Tis why I didn't bother..

But.. You will eventually damage the threads if you are removing and refitting the screws into the Alu' head. Its only a matter of time. A little too much torque and bingo. Problems!

But..Don't fix what's not broken sure does apply. If you have a situ' when the threads are going (or gone), that is the time to take action. Don't do it for the sake of an 'upgrade'.....Stick with the studs.

But If I was def' going for Allen Caps I would fit steel inserts. Just MHO....Its to each their own.. Decisions decisions...

AB....

[Alex]

Hi All,

Nobody has mentioned using the tried and tested steel studs with spring washers and brass nuts yet? In 30 years of using them on various makes of car I've never needed loctite and never had any truoble with them.

Using bolts into the head will over time lead to thread troubles and helicoils/aluminium welding being needed.

As for pulling the manifold free of the head, put a block of wood under the sump and jack it up a bit on the engine mounts. Works a treat for me.

Alex

[Sea Ranch]

As for pulling the manifold free of the head, put a block of wood under the sump and jack it up a bit on the engine mounts. Works a treat for me.

Sorry; not following you, Alex. Jack up the engine a bit and then . . . ?

[alexblack13]

Hi All,

Nobody has mentioned using the tried and tested steel studs with spring washers and brass nuts yet? In 30 years of using them on various makes of car I've never needed loctite and never had any truoble with them.

Using bolts into the head will over time lead to thread troubles and helicoils/aluminium welding being needed.

Alex

Both of those point were mentioned in various posts too Alex..The one directly befor yours for E.G.

''stick with studs''.... That means steel studs brass nuts and spring washers. Standard fit in other words..

[types26/36]

''stick with studs''.... That means steel studs brass nuts and spring washers. Standard fit in other words..

I was always taught not to use spring washers on exhaust manifolds as the heat causes the spring washer to loose its tension, you may as well just use flat washers with a brass nut which is what most manufactures do although some manufactures do have a special locknut.
Alternatively a dab of high temperature RTV (blue) on the threads will also keep the nut in place.

[alexblack13]

That is true. But the spring washer still has a certain amount of grip & I have never found a slack nut yet with one under it.

I've seen cars with Nylocks on though & they definitely don't work well....

There are a few stiff-nut types which would lock ok but they can be hard on the studs and end up working like a stud remover when you try and get them off. (could be handy?) I think Brass Nut and a Spring Washer works fine. Like (the other) Alex Says..

To each their own and just MHO.....

Al' .......

[billwill]

Mine have always had brass nut and no-washer, I think.

[oldelanman]

Mine have always had brass nut and no-washer, I think.

And mine - just brass lock nuts or "stiff" nuts as Alex B calls them and no washers.

[GrUmPyBoDgEr]

Nimonic studs & silver plated nimonic double hexagon self locking nuts were a mod' on my Zetec.
"The dog's danglies"
If you ask about the price you can't afford them

Stud corrosion is a major source of problems. The retaining nuts just jam up on it & you end up either winding the studs out or even breaking them.

Good quality cap head (Unbrako) bolts are a good alternative IMHO, as suggested by many on here.

John

[alan.barker]

well chaps i feel that i must have my say.
after 38 years of lotus, i have always used steel studs, spring washers and brass nuts.
never a problem and i have never needed to helicoil for an exhaust manifold.
it think it speaks for it's self
Alan B

[garyeanderson]

I have read both discussions This one and Alex Blacks topic , (see link below)
elan-f14/exhaust-studs-versus-helicoiled-holes-t21618.html
on swapping studs for Socket Head Cap Screw and I don't understand the need for folks that use there Twin cam for street use have any need for "quick" exhaust gasket changes. Access is one of the only reasons that I can see. Even then there is an alternative a SHCS in the form of a k-jet nut (MS21042-5 lubed or MS21043-5 no-lube). Although not quite a small as a 1/4 inch allan head on a 5/16 SHCS, these nuts are all metal self locking and have a 3/8 inch Hex head on a 5/16 unf thread. Access is a bit bulkier than an allan head but with a 1/4 ratchet and flex 3/8 inch socket and a couple of short extensions access is possible on all studs. I once had an Elan DHC that bought a new Double Stainless 3 piece exhaust manifold (yep last time I did that) and the 1-4 flanges were not welded on so that all 4 holes were not perpendicular and co-linear. It would not slide on to the studs. If bolts had been used the manifold would have started the SHCS cross threaded. Because I had the studs I could see that the studs looked right. I was able to tweek/bend the flanges in a vice by giving it some physical twisting. In the end my friend Kenny told me about K jet nuts and thats all I use now. Please use what you like and do as you please its your Twin Cam.



http://www.aircraftspruce.com/catalog/h ... S21042.php
http://www.aircraftspruce.com/catalog/h ... S21043.php

http://cgi.ebay.com/Jet-Nuts-MS21042-5- ... 45f08a038e

These nuts work well but will not address the issue of exhaust manifold removal in the Elan, but will make access quite good.

[types26/36]

I just used some of these myself on my S3 SE (down pipe to manifold) due to access problems, 5/16 unf, 3/8 socket with 1/4 drive and bit of copperslip on the threads.

[GrUmPyBoDgEr]

I just used some of these myself on my S3 SE (down pipe to manifold) due to access problems, 5/16 unf, 3/8 socket with 1/4 drive and bit of copperslip on the threads.

Almost identical to what I've used although mine being on a Zetec are M8 of course.
Mine are silver plated, do yours have any form of anti-galling coating?
Double Hex' is the way to go, being flank drive rather than the "point drive" of a hexagon nut; space saving regarding smaller socket size is also a big plus but I expect that the pictured K-nuts will also offer similar reduction.

Cheers
John

[garyeanderson]

I just used some of these myself on my S3 SE (down pipe to manifold) due to access problems, 5/16 unf, 3/8 socket with 1/4 drive and bit of copperslip on the threads.

Almost identical to what I've used although mine being on a Zetec are M8 of course.
Mine are silver plated, do yours have any form of anti-galling coating?
Double Hex' is the way to go, being flank drive rather than the "point drive" of a hexagon nut; space saving regarding smaller socket size is also a big plus but I expect that the pictured K-nuts will also offer similar reduction.

Cheers
John

Hi John

Someone said open your hand and dropped a bunch in my palm, I took 8 and Wow life's been great! Yes they were free so I used them. Had I bought them maybe I would have gotten a 12 pt. version as almost all nuts are cheap to buy new.