Thread sealant on all big block exhaust manifold bolts, right?

[Plyrr471]

Off season work continues now that the really cold weather has seemed to let up a bit here in NY as documented here:

Winter off season project engine compartment “clean up” and engine repaint.

Just making certain all of my new oem (repro) exhaust studs should get thread sealant. I was planning on using this Hi temp Permatex, which I also used on the intake manifold bolts.

Just curious if I should use an anti-seize on the nuts that fasten the bolts, if so suggestions please? I’d hate to have issues down the road if I need to remove them, as one of our members has been asking about lately. Thanks as always guys.

 

[gkent]

Yes, thread sealant on the studs. Anti-cease on the nuts is a good idea BUT the thread sealant is teflon so worst case if a nut is stuck the stud will come out.

I'm always leary about sealant not getting much further than a couple threads so in things like this I put a dab in the hole as well as what I put on the stud or bolt.

 

[R413]

906 heads have all holes into water. With the studs out see how far you can put a tool into the hole,and if it bottoms out.

Does your 71 RR have the 3462346 heads still on it?

Anti sieze is good on the nuts. I like the permatex copper based stuff.

 

[Plyrr471]

Thanks gkent. R413, the are the original heads, I don’t know the casting number off hand, but I would assume so.

 

[ynst]

Yes, thread sealant on the studs. Anti-cease on the nuts is a good idea BUT the thread sealant is teflon so worst case if a nut is stuck the stud will come out.

I'm always leary about sealant not getting much further than a couple threads so in things like this I put a dab in the hole as well as what I put on the stud or bolt.

It's called anti seize, btw.

Anyway, I've been using plain old Indian Head style gasket cement on the threads for better than 60 years and have never had a leak around the threads.

 

[gkent]

It's called anti seize, btw.

Nope ! On those studs/bolts you specifically want "teflon pipe sealant", NOT anti-seize !!

Gasket sealant works too but pipe sealant screws in and out easier.

 

[ynst]

Sorry for the confusion. I was, in the first paragraph, correcting the previous poster's spelling issue.

For the sealing issue, I was referring to the coarse threads that get screwed into the block, not the fine threads where the manifold nuts are used. The coarse threads get the gasket cement and the fine threads get the anti seize (or anti-seize if you like that format)

I used graphite based anti seize on those nut threads for years until the copper based anti seize showed up. Now I use either on anything threaded UNLESS it's going into a water jacket.

I stock both types but use the copper based stuff if electrical connections are involved due to the conductivity of the copper.

 

[khryslerkid]

Last time I used liquid Teflon paste on the studs into the head. Maybe the holes weren't clean enough because I had a couple of leaks. Went back to my tried and true Permatex #2 and no problems.

You can buy brass nuts for the manifold. Been doing that for years on exhaust components and they won't deteriorate or rust.

 

[1 Wild R/T]

I've used Indian Head Shellac on the portion of the stud that screws into the head for as long as I can remember... No leaks ever..
I don't use anti-seize, it's probably a good idea, but I live in California so there's very little moisture & stuff rarely has any problem with seizing...

 

[OzCharger69]

yes. I run bolts. Make sure you put the sealant on both the female and male side

 

[ynst]

I use brass nuts as well but not on the extended nuts between the last two cylinders. Those require copious amounts of anti seize.

 

[33 IMP]

Running a screwdriver or the like into the exhaust manifold bolt holes before using a sealant is a good idea.
I have a couple pairs of early bbm heads that have one blind hole on each end.

 

[khryslerkid]

Running a screwdriver or the like into the exhaust manifold bolt holes before using a sealant is a good idea.
I have a couple pairs of early bbm heads that have one blind hole on each end.

I've seen that also until I used a set of 452 heads and they all were wet holes.