Sealing Dynomax headers

[340 Dart]

I have been having problems getting these to seal in the past. The engine is going back together on Saturday on the 75 dart and I wanted to finally fix the problem.

I have heard that you can use permatex, but is it in addition to the gaskets or in place of the gaskets?

Do you let it set up a little?

What kind exactly do you use? Red, Black, Blue or other?

 

[Coyote Jack]

I had the same problem with mine. All I did to cure the problem was double up the gaskets. (2 on each side). I also found that if you tightend up the ends first, that helped. ie: #7 and #1

Jack

 

[dgc333]

I tried several different header gaskets and found that doubling up Fel-Pro header gaskets with a coating of red high temp permatex on each side of each gasket has worked great. I am coming up in 15k miles with no leaks.

 

[redfastback]

a new brand of gaskets called REMFLEX makes a nice THICK graphite gasket that seals really nice. check you local speed shop.

 

[AdamR]

Cut the flanges between the ports. Then your only sealing each port individually instead of trying to seal them all at once.

 

[340 Dart]

Cut the flanges between the ports. Then your only sealing each port individually instead of trying to seal them all at once

:cheers:

That makes so much sense. I have seen headers like this but I never even thought of doing it.

Anybody else done this with success?

 

[lead69]

Ive cut my headers between ports with good success but dont overtighten or you will really bend the flanges as theres less support.Also my brother used to work at an exhaust shop and turned me onto an exhaust sealer that is awesome,its a tar/silicone like substance and works very well but doesnt harden like concrete so you can actually remove your header.Its actually available at napa and its there product,you just coat both sides of the gasket and go,I use it on every header and never have problems.

 

[340 Dart]

tar/silicone like substance and works very well but doesnt harden like concrete so you can actually remove your header.Its actually available at napa

Swung by NAPA and ordered some. I will leave my headers intact for now and try this first.

Anybody else cut the flanges?