View Full Version : installing Intake Exhaust mainfold

11-19-2008, 09:56 PM
Do the manifold gaskets for the intake/ exhaust need a sealing compund?

What about the exhaust flange (3 bolts) to manifold?

I'm planning on using anti-sieze on the bolts but was wondering about the mating surfaces. I just got the exhaust manifold back from the shop after having the sheered bolts removed and the face resurfaced and don't want to have a leaky intake or exhaust.

11-19-2008, 10:12 PM
Nope. those get installed dry. I'm not sure I'd use anti-sieze on those nuts (especially the 3 exhaust flange nuts) as I'd be worried about them backing off. The exhaust heat will turn the antisieze into powder in no-time flat anyway. Lock washers would be advisable.

11-19-2008, 10:39 PM

11-19-2008, 11:01 PM
I replaced my manifold (stock) not long ago as my original had a crack. If your parts are original they should match up fine. If not measure (mic) them for thickness as the intake and exhaust elements must be the same thickness for the flange nuts to exert even pressure. Since you had the exhaust resurfaced this is important.
The gasket is put on dry and I just put one drop of oil on each stud prior to tightening and I did use lock washers.
For a few weeks, once a week, after driving I'd retourque everything until they took a 'set'. They will eventually 'lock up' and can be left alone.

11-19-2008, 11:45 PM
Nope. those get installed dry. I'm not sure I'd use anti-sieze on those nuts (especially the 3 exhaust flange nuts) as I'd be worried about them backing off. The exhaust heat will turn the antisieze into powder in no-time flat anyway. Lock washers would be advisable.
I've been using copper-based anti-seize on the manifold studs for over 30 years; and haven't noticed any increased tendency to back off. But I do use new lockwashers almost every time, as they lose their spring from the heat.

Anti-seize still works even after it "turns to powder" (which really is what it is to begin with, it's just the oil carrier that evaporates, kind of like paint drying).

Although not original, I also find that heavy flat washers under the lockwashers on the outermost studs (the ones that go through the holes in the exhaust manifold) also help keep the joint tight.

11-20-2008, 11:36 AM
Prb51 makes an interesting point. I had a tr3 engine that I could not get the manifolds to seal and the problem turned out to be a warped intake manifold. When I looked at it close, I could see the warping. It was mostly in those little ears on the manifold. I basically just took a file to it and that has been many years now.

11-20-2008, 11:39 AM
I think anti-seize is very important on exhaust mounting studs. The heat in that area promotes corrosion which, if you are lucky and it really is a few years between removals, leads to the creation of those broken studs that you just had fixed at the machine shop. A good high-temp anti-seize is your best insurance that the nuts will just turn off of those studs when the time comes. Broken off studs in the head are no fun!

11-20-2008, 12:42 PM

Probably won't turn to dust under 1200-1500 degree exhaust temps.

11-20-2008, 06:38 PM
:wall: Oh man, I really didn't want to have to go get a radiation meter just to work on a car....

11-20-2008, 09:59 PM
I'm using 5000 deg never seize, you can get it at Napa, about $12.

11-21-2008, 11:55 AM
I'm using 5000 deg never seize, you can get it at Napa, about $12.

But does it say "Nuclear Grade?"

IMHO, the best part of having Nuclear Grade anti-seize is the fact that it says it's "Nuclear Grade". I can't name even one other product in my home with the words "Nuclear Grade" on it.

11-21-2008, 12:18 PM
I agree, it could only be better if it said 'double secret probation Nuclear Grade'.

11-21-2008, 12:47 PM
I concede... 20 to 1 all say to use anti-sieze. Me saying not to was just my personal opinion. I'd listen to those guys. They have stronger arguments than I.

11-21-2008, 12:56 PM
I've used plain ol' 2000 deg. "non-specified grade" anti-seize on my air cooled Volkswagen head studs and my BMW motorcycle exhaust nuts since 1973. I haven't broken a thread in all that time. Nuclear Grade may well be better in some way -- certainly in conversation -- but I can't argue with the 100% effectiveness that I have experienced for 35 years with my, ummmm, crap.

I regard air-cooled VW head studs as the ultimate test of anti-seize. Those babies get <span style="font-style: italic">HOT</span>, corrode like crazy, and are notorious for breaking and then being difficult to repair in the alloy heads. Anything that can produce 100% results in that service will work on a TR -- at $4.95/jug at your FLAPS...


Geo Hahn
11-21-2008, 06:03 PM
What is the thinking about the nuts used on the manifold? I have one engine (TR3A) that I have 'thick' nuts on it... about a half inch thick or so. The other (TR4) was plain steel nuts but I used brass the last time I had the head off.

Never had a problem with any of these (knock wood dash) but wondered if there is a best way.

11-21-2008, 06:32 PM
I don't think it makes much difference, as long as you smear some anti-seize on the studs. I do prefer the tall steel nuts, except maybe on the last outer studs. Access to the center studs on the TR3 is pretty limited, and the tall nuts seem less apt to round than the brass ones, plus easier to get ahold of than the short ones. Plus the lockwashers tend to chew up the brass nuts.

But I wouldn't say it's enough difference to either delay assembly while the 'right' nuts show up; or take off the 'wrong' ones just to change them. I just try to find the tall nuts when I put it together, and use whatever I find.

AFAIK the tall steel nuts are original; and available from the usual suspects.

11-21-2008, 06:52 PM
I've the thick steel nuts but have had good luck with out of round brass nuts for headers. Mercedes used these on their 1950's/60's vehicles and they lock in place but are only used once (unless you rewhack them which I've done).

11-23-2008, 11:00 PM
Nuther thing, In my opinion and experience is, don't over tighten the nuts, start in the middle and work out to each end little at a time, evenly.
My Triumph guru says he's never seen one to loose and many, many to tight. I overtightened mine made a leak and broke and ear.
Now I choke way up on the rachet or wrench so I don't have a large lever arm and just go to snug. Make sure the footballs are well centered on the tabs.
I also use anti-seize and lock washers.

11-23-2008, 11:30 PM
Good point on torque, I use a 1/4" ratchet and that is hard to over do it with that.