I have searched for at least an hour - can't find the final verdict on header install

[DSRTRDR]

I am planning to install (as a replacement for a cracked MAF 2x3into1 header, also called 6into1) the exact same model new from MAF

I remember the copper gasket sealer for the manifold gasket, but what was the verdict on 2 versus 1 gaskets?

Ed, Poser......?

Thanks in advance

 

[FJ60Cam]

I took the advice from Mark W to use 2 Felpro gaskets. I didn't use any sealer, just the gaskets. It's been about 8 months, 6-8000 miles and still holding up.

I thought that the two gaskets would settle some, but when I went to re-torque the bolts, everything was still tight.

 

[1973Guppie]

I normally in the past have used 2 paper gaskets with good results on the cheaper headers. IMO, the most important thing is to check and recheck the tightness of the header nuts after install and initial warm up. Some type of locking nut or other will help to make sure they don't back off from the header.

 

[Pighead]

I don't think there is a final verdict...it seems to be personal preference. I get by fine with one good gasket, some people like two gaskets. Whatever works for you...

 

[40's rock]

I just had this issue with an old maf header...had to cut down two old gaskets for all of the exhaust ports..sealed them together and then bolted up with a new manifold gasket....my header was slightly thinner than the intake, the bolts wouldn't pull it down tight enough. I always laughted at the PO using mulitple gaskets...now I know why

 

[ken_79-fj40]

I tried the 2 gasket thing once, and it leaked after a few months. I've been using a single fel-pro with copper coat on it ever since, and until I had to pull the header to weld up a small leak last summer I hadn't had an issue with the gasket. Probably was on there for 6-8k miles. One thing I did that seemed to help a lot was I replaced all the bolts with studs and nuts.

 

[emtee]

Ken,

Did you use 10.9 grade (Grade 8 equivalent) studs on that? If so, do you recall where you sourced them? I'm trying to decide whether to go stock on my manifold rebuild or use studs exclusively...

 

[Pighead]

I've always used only studs and nuts. And I only use OEM studs and nuts. And the correct OEM washers.

 

[1973Guppie]

a couple other tips, have the header flange machined at a local machine shop, use studs and nuts for sure, I remember having to cut washers in half to take up the difference in thickness between the header and intake manifold. Cheesy, but it worked. When I do the 2f rebuild in the 55 I will be looking to other solutions other than the half washer thing.

Noah

 

[Pighead]

The half-washer trick is a good one...do you JB weld the half to the whole washer?

 

[FJ60Cam]

If the new MAF 6-1 has the same flange as their ceramic coated headers (as stated on their website), then you shouldn't have any problems with thickness or fit. The fancy ceramic ones mated with the intake manifold perfectly.

 

[Poser]

The intake manifold is aluminum. Many of the intake manifolds that I have seen over the years have the area where the fastener secures the manifold to the head deteriorated to the point that they are not all the same thickness, which will provide uneven clamping force and can result in intake leaks or exhaust gasses burning the gasket away, creating exhaust leaks at the header.


Also something to note is the fact that the F engine uses 10mm studs to secure the manifold assembly to the head, whereas the 2F uses 12mm studs and bolts, and two 10mm bolts at the outer ends of the exhaust manifold/header.


I have not found consistencies with the F and 2F intake fastener flange area.

 

[fjatheart]

1 felpro and some copper permatex

It all depends on how out of wack your intake/exhaust face is. I tried TWO gaskets and permatex and the thing leaked like crazy. I tried it twice with TWO and I found ONE Felpro and permatex did the trick. I had my intake re-surfaced and used the ceramic MAF header.

My Dad used the same header and had the intake resurfaced and two Felpro with permatex worked fine for him the first time. He has been running this for over a year.

 

[bsevans]

The intake manifold is aluminum. Many of the intake manifolds that I have seen over the years have the area where the fastener secures the manifold to the head deteriorated to the point that they are not all the same thickness, which will provide uneven clamping force and can result in intake leaks or exhaust gasses burning the gasket away, creating exhaust leaks at the header.


Also something to note is the fact that the F engine uses 10mm studs to secure the manifold assembly to the head, whereas the 2F uses 12mm studs and bolts, and two 10mm bolts at the outer ends of the exhaust manifold/header.


I have not found consistencies with the F and 2F intake fastener flange area.

It is a very easy process to tig weld the seats and recut them to the same step thickness as the header. You can also use this process to cut different heights for the intake seat to match the seat height for a factory exhaust manifold that has been surface to remove the warp (each seat height will most likely be different). When I installed the tuned two piece header from MAF I had the local machine shop I use weld a bead in all the intake seats. They also surfaced the intake manifold after welding and I used a router to cut the seats the same thickness as the header using the surfaced face of the intake manifold for the router and the existing semi-circular relief for the mounting bolt/stud as the guide. With the right Freud router bit and a good router, cutting the new seats took about 5 minutes once I had the depth properly set. The new intake seat heights were within .005/.010 of the header seat height.

 

[Josie'sLandCruiser]

Hi All:

PM "Spotcruiser," he just went through this process.

Regards,

Alan


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I am planning to install (as a replacement for a cracked MAF 2x3into1 header, also called 6into1) the exact same model new from MAF

I remember the copper gasket sealer for the manifold gasket, but what was the verdict on 2 versus 1 gaskets?

Ed, Poser......?

Thanks in advance

 

[65swb45]

The half-washer trick is a good one...do you JB weld the half to the whole washer?

IIRC, pardion started with extra thick washers and just ground down one half of the washer so that it could be used to balance out a low intake OR exhaust. I'd never seen this done until I had the opportunity to work on his daughter's rig at Rubicon Springs two years ago.

Though I have not had the need to try this yet, I think this is an interesting option and thought I would share it, along with the source.

Best

Mark A.

P.S. As far as the gasket question: single, quality gasket with copper coat on the exhaust ports ONLY! NEVER had an issue with this arrangement.

 

[Ziffdaddy]

For what it's worth, when I put my head back on, I used one gasket and the exhaust ended up blowing out part of it. I doubled it up and it's been gravy ever since.

 

[bsevans]

IIRC, pardion started with extra thick washers and just ground down one half of the washer so that it could be used to balance out a low intake OR exhaust. I'd never seen this done until I had the opportunity to work on his daughter's rig at Rubicon Springs two years ago.

I tried this method when I had my intake and exhaust manifolds surfaced as a unit to remove the warp. I was not pleased with the results and went to the process I described above, which has worked flawlessly. I also think eliminating stepped washers makes the assembly much easier especially since each washer has to be stepped to different thicknesses for the intake and exhaust step thicknesses at each mounting pair.

 

[DSRTRDR]

P.S. As far as the gasket question: single, quality gasket with copper coat on the exhaust ports ONLY! NEVER had an issue with this arrangement.

even though I read your post afterwards, that's what we did

 

[DSRTRDR]

o.k. here is the report:

all bolts came out without issue, as did the two nuts

the intake manifold was already ground due to the fact that there was a header there in the first place

the new header was indeed a total bolt-on replacement

except for the collector being ever so slightly shorter, which had us missing about a half inch at the flange to the exhaust pipe - relocating the exhaust further frontward solved that problem

I have to say, this went amazingly smooth not even any need to take pics

and: the cracked header was cracked worth than visible from the outside when still in the truck