VETDRMS

This has been an ongoing issue for almost a year now.
I have spent over $150 on gaskets and bolts trying to get these stupid things to seal. They are the dynomax ceramic coated headers.
I have used anything from a standard paper gasket (which worked best) to the ultraseals, to the coppers. And it always leaks right in the center between cylinders 4-6 and 3-5. I think they headers may be warped, when i first got them i had them surfaced to make sure they were flat. I was later told that they put a natural bend in the header so it will squish flat and seal. Could the surfacing have removed that, and that is why they won't seal?
The bolts are tight, and have been tightened consistently. I have also tried some ultra-copper, but it does not work.

I may just decide to scrap them and get some hooker super comps or some Thorley nickle plated headers. Any suggestions? :cheers: :cool:

69er

Percy's High Performance aluminum gaskets and some Stage 8 bolts?
Percy's are soft aluminum that contour fit.I used the same gaskets before and after my rebuild.


[Modified by 69er, 1:08 PM 12/24/2002]

427Hotrod

Is there a solid flange that connects them all together? Sometimes if they are warped, you can cut the flange so that tubes #2, 4-6< and #8 are all separate. That will help them pull up to the head straight.

Sometimes soaking paper header gaskets in water overnight helps. Install them wet and then crank it up. As it idles and warms up keep tightening them a little at a time. Then let it cool overnight and retighten in morning. Might work.

I've also seen folks use stock metal replacement gaskets for manifolds that sometimes seal great.

Maybe studs that are able to keep bolts from loosening.


Hope it helps.


JIM

Frankenvette

RELAX, This is a common problem. I battled a leaking passenger side header flange leak for over a year with my Dynomax ceramic coated headers. I got Percy's soft copper gaskets, stage 8 locking header bolts off ebay and some high temp gasket sealer. I put the gasket sealer on both sides of the gasket. This will seal any imperfections in the o-ring on the header flange. I discovered that the Dynomax o-rings are not very smooth/even. In fact, I was very disappointed in the quality of the o-ring. A little hi-temp gasket sealer like Permatex will do the trick. On high quality headers, you don't even need a gasket, just some sealer.

Jim

mrvette

The flange has to be 3/8 inch thick....and with NO weld rings on the flange/engine side...smooth straight across.....if there are weld rings..they will leak.....my old set did all the time...
the new set here is the above preferred construction and not one leak with white thick paper gaskets in allmost 8 months now...

GENE

redvetracr

VETDRMS,
As posted above CUT THE FLANGES use a hack saw or a Sawzall, once cut you will see how warped/twisted your flanges really are. It worked for me!! ...redvetracr

AlwaysWave

:iagree:

MoMo

I had that problem with a pair of Hooker Competition headers on my L98 IROC-Z Camaro driver. I finally got them to seal by dimpling the headers so that I could get a modified box end wrench around the bolts. If this doesn't hold them, then the next step would be some type of locking header bolt.

On my Corvette, I have ARP header bolts drilled for safetywire. But the Corvette actually has enough room to reach the bolts with a set of safety wire pliers. That's not the case on the IROC. Can't even fit your hand back there.

I agree with cutting the header flange. In the car that would be tough, but you could probably do it with a good sawzall. And that would be much easier than removing the headers.

VETDRMS

69er Thanks, i'll take a look at those. I've already spent 150+ on gaskets/bolts/ect trying to get them to seal, so what's another 50 or so :)

427Hotrod I have been thinking about cutting the flanges for a while. I think i will probably go this route, AND get the Percy's gaskets with permatex. Are there any drawbacks to cutting the flanges? Thanks for the tips :cheers:

FrankenvetteI know its a common problem, but it sure is a pain in the ****! :D I think i'll get the Percy's next month. Thanks.

mrvetteWhat headers are you running now?

redvetracrThat is the plan! :smash: :cheers:

MoMoI'm going to take them back off in a week or so and cut the flanges (once the new gaskets get here). I'll let ya'll know how it worked :D
Thanks again for all the help, and:

MERRY CHRISTMAS :chevy

Chris69

My 02... Try the Percy's aluminum before cutting the flanges... If that doesn't work then start cutting... I just put those on mine, plus I haven't read where anyone has had a problem with those not sealing. Too new on mine to rate though. :cheers:

p.s. Just wanted to add, for example, that the original shorty headers on the '81 did not have a full flange, plus they didn't use a one piece flange gasket -- there were three pieces per side, so cutting the flange is not a radical thing to do. Good luck!


[Modified by Chris81, 9:30 PM 12/24/2002]

redvetracr

VETDRMS,
Once you cut the flanges you will not believe how much they will "spring" out of shape. ...redvetracr

VETDRMS

redvetracr Does this "springing" out of place cause any problems on installment? Are there any downsides to cutting the flanges? I've heard its a good fix, but what are the problems associated? Apart from ease of manufacturing them, why do they just not ship them without the flanges? I will probably take my trusty sawzall to them quite soon.

Merry Christmas :cheers: :flag

Frankenvette

Forgot to mention in my earlier post, I cut my flange, but it did not help. Cutting the flange has no negative side to it. In my case I thought maybe the flange was warped, however, the leak was due to the o-ring. If you do cut the flange, wrap the section you are going to cut with tape first. Will help prevent flaking of the ceramic coating. I used a hack-saw, and it took only a few minutes.

Jim

Alwyn678

As others have stated ........Percy's worked Great for me :cheers: