Exhaust Manifold Seal

[LaGrasta]

C'mon, what's the best way to ensure it stays put? Last time I did this I installed tab washers and here I am doing it again, less than a year later. UGH!

I have a new Fel–Pro gasket for it. One guy suggest use two. Another says to use silicone sealant. I'm not sure what to try next, only I'm tired of doing it over and over.

On a high note, I think i have the valve cover sealed ;-)

 

[gearhead138]

I've read that you can soak the gasket in water to make it swell, then install it. Make sure the bolts are nice and clean and put anti-sieze on then, that will lube them and ensure you get proper torque.

 

[BUZZ]

I like to go back and retighten the bolts at least once a week for the first month. If there are any pits on the head or manifold sometimes two gaskets will seal it, but the only sure way it to send it to a machine shop.

 

[fordconvert]

Im using the ramp lock bolts/washers. Have not touched them for quite a while now. They did not even move the first few weeks when I checked them.


Now that I think about it I dont think I am running gaskets. Had the shop throw that side on the belt sander along with the manifold. I know the other motors I did the last few years are that way so Im guessing I did the ford that way also. When I first got the car and new manifold I did run gaskets because the head was not fresh machined.

 

[LaGrasta]

Due to my aftermarket A/C compressor, removing everything really was a pain! This combined with the tab washers that I had to somehow unfold enough to get a socket around was so bad, i won't reinstall them. The exhaust gasket was "holey" mess. This is the second time in the last two years I had to replace it.

At any rate, I removed everything and cleaned it all up. After asking numerous opinions, I think I'm going to use my new FelPro gasket WITH high temp gasket maker.

Thoughts?

 

[XFlow_Fairlane]

is everything flat?

this is a cast mani and not a header right?

if everything is flat I would saw just use some sealer. can you get in there with a 3M pad on a angle die grinder to "scuff up" the surface?

 

[bigcatchdaniel555]

Yup same here my gasket went bad twice in a year. This time I used copper silicone by permatex and retightened the bolts every time i had the car out until they stayed tight and now i'm looking at about 2 months with no leaks signs all is good.

 

[70 grabber]

I thought I had an unusaul problem! I have been through 2 exhaust donots in the past year as well.Only 2 because I have not re-adjusted every time I hear it loose.IN fact I think my carb is bad as well every few days I readjust my timing with a vacume guage but it always seems to wander!I think this is due to a single barrel with minimaladjustments.sorry for aditional info but looking for same as you!!

 

[mustang6]

I have had excellent results with the Remflex gaskets http://www.remflex.com/ with headers on my inline six.

 

[Drumhead_Dan]

I'd be looking at my pipe brackets and braces to make sure that pipe isn't bouncing around on that donut issue.

If the OP issue is between the head and manifold, make sure you're using a torque wrench and the right tightening sequence. Chase the threads while you've got it apart if you can. The anti-sieze is a grand idea, but I'm not sure how it might affect your torque values. You can also check to make sure all your bolts are going in without bottoming out.

 

[LaGrasta]

Well, it's done. I ended up using high temp gasket maker, non-hardening on both sides of the Fel-Pro gasket. I put about 30 miles on it so far and it's still tight and quiet. How many miles until I retorque?
I'm not looking forward to retorqing as three bolts are hidden behind the A/C and starter. I'm glad it's done though, i really want to drive it to the Mooneyes Christmas Party at Irwindale Raceway this coming Saturday.

 

[LaGrasta]

It's now Thursday and I've put a few hundred miles on the car since replacing the gasket. The gasket maker is completely brittle, but there are still no leaks! Thank Christ! I did retighten (no torque wrench used) the donut this morning as it had a leak. That's a quick, cheap, and easy retighten compared to the manifold!

So my question is when should I retorque the manifold? If and only if it starts to leak or after a said amount of miles? I used thread lock if that means anything. No tab washer this time though. What a pain to get those off!

 

[falcon fanatic]

This is especially a problem if you use any kind of paper-like gasket. The white one that came with my Clifford's header lasted, oh, about six months. When I took it out it was disintegrated. The Auto-zone one I put in when I redid my head about the same.

I now have a mulit-layered metallic one that I got from Mike, I think. It is the same type used by Honda for OEM applications. I can say it was the only thing that would work with headers on a Honda, and I installed over a dozen of those. Every other type would leak within weeks. I haven't put this in yet since it is such a PITA and I'm thinking about a cam swap, but my current manifold has at least three leaks, probably more.

 

[LaGrasta]

Okay, it officially leaks now, between the 3rd and 4th cylinders. What a PITA!

I hope only a retorque solves it. ...wishful thinking, I know. I'm thinking of only retorquing the center bolts as they are the only ones leaking from what I can tell. Thoughts?

 

[ludwig]

Did you use the thick orange sealer goo? It worked great on my original paper gasket from Clifford.

Plus, do you have the manifold bolt locks? You can get a set at the bone yard off of another block. (Of course they have to take the exhaust manifold off to get these too, so they won't be free.)

 

[falcon60]

The only way I've found to really never get a leak there is to mill the manfold so it's absolutely flat,and to be sure the head surface is also in very good condition with no scale,low spots,etc and then use no gasket at all. A bit of silica-based exhaust sealer (notice I said silica,as in sand,not silicone) is ok to fill minor imperfections.
When you use a gasket,especially the almost universally crappy quality stuff commonly available,the bolts don't really come loose....the gasket compresses and shrinks after a while,leaving the bolts loose...then the paper part of the crap gasket burns away leaving only the porous steel layer which eventually burns away too.
The small six manifold is a real tough one to seal since it runs very hot,is thin and has that large center port to deal with. If I had to run a gasket I would tighten it daily for the first week,then check it at least once a week for a while to make sure it was behaving. Even then I would expect a failure sometime.

 

[62goldenrodvan]

Lagrasta,
Either manifold or header,
I use red rtv and keep checking the bolts.
Make sure the manfold is flat and smear a thin film around each port.
I don't care for gaskets, I had no success with them.
Old drag racing trick.
Kevin.

 

[aahsac]

My experience is pretty much like falcon60 said, except it was on a 455 in a motorhome. On a long uphill pull the original exhaust manifolds would glow, leak and then crack. I had the exhaust face machined on the heads and installed Thorley headers using the exhaust sealer. Since the headers were new I retightened the bolts once and it never leaked.

 

[JGTurbo]

Permatex specifies their Ultra Copper silicon gasket maker for header, turbo, and exhaust gaskets. I used to think it wouldn't hold up, but I gave it a try on several exhaust components and haven't had a leak yet. Then I was reading up on a 1000+ horsepower twin turbo LSX build in a magazine and saw some of the pictures of them assembling it. The guy had a tube of Ultra Copper in his hand and he applied it to every exhaust flange on the entire set up (no "gaskets" anywhere). This was a professional build too. Now I'm sold!

 

[LaGrasta]

Permatex specifies their Ultra Copper silicon gasket maker for header, turbo, and exhaust gaskets. I used to think it wouldn't hold up, but I gave it a try on several exhaust components and haven't had a leak yet. Then I was reading up on a 1000+ horsepower twin turbo LSX build in a magazine and saw some of the pictures of them assembling it. The guy had a tube of Ultra Copper in his hand and he applied it to every exhaust flange on the entire set up (no "gaskets" anywhere). This was a professional build too. Now I'm sold!

Thank you so much for all the advice, great repsonces. I used both the Fel-Pro metal/paper gasket combined with high temp gasket maker. I guess if I have to pull it again, I'll try the Ultra Copper with no gasket.

I retorqued it last night, only in the center where it was leaking. Going from my original 13 ftlbs. to 15 ftlbs. Afterward when driving it, the exhaust note was drastically different, but still a leak. I'll torque once or twice more then try to get the moral up to pull it it yet once again.

Should I be retorqueing when hot or cold?