Exhaust manifold studs - what sealant?

[uk-maxie]

Hi guys

What would you recommend to use for a leak-free seal on those pesky manifold studs?

Does the sealant need to be high-temp? I presume it does but there are good sealants like loctite that would be easy for me to get hold of, but might not withstand the temperature?

ARP Sealant sounds like a good option but they even state on their website that you can use loctite instead. Doesnt say anything about high-temp tho.

And my brother says he read somewhere to fit the studs finger-tight? :icon_confused: Or how tight should they be fitted before you torque the manifolds up? I think I just screwed them all the way in, first time around.

Our 440 sprung a bit of a leak around one of the studs on No1 cylinder when we filled the rad in preparation for starting the rebuilt engine for the first time, so we now need to strip all the bits off in that area that we've carefully assembled over the last year, so we can redo that stud. :angry1:
We originally just used PTFE (plummer's) tape. All the other studs seem ok tho.

Any experts out there? :grin:

 

[Dako]

I used Permatex 'Ultra Black' at the recommendation of my machinist. Sealed up nicely.

 

[Histoy]

Hi temp copper RTV has worked well for me.

 

[uk-maxie]

Thanks for the advice guys, I'll see what we can get readily over here :icon_thumleft:

 

[Garys1969RR]

Are you talking teflon tape for plummers tape? Never heard of that, but I think the hi temp rtv should work. Ultra black would be best as DAKO recommended. Any hi temp rtv should work ok, whether black, red or copper. I double nut the stud and tighten it in solid, then remove the nuts. That way when you remove the manifold next time, the stud stays in there. Good luck!

 

[uk-maxie]

Thanks Gary! Yes, PTFE (also incorrectly known as teflon) tape, commonly used by plummers (see Wikipedia pic below). Can be very effective but when the offending stud was removed there wasnt much evidence that any tape had been there :eusa_think:

My brother (the car's in his garage) removed the manifold and all the studs on that side during the week and replaced them with some of this

http://www.hylomar.co.uk/index.php?option=com_content&view=article&id=62&Itemid=70

on the threads.

I'm going to lend a hand tomorrow putting it all back together so hopefully will be able to report back with some good news...