header leaks. need confirmation on gaskets, etc

[ttribejr]

I am going to pull my OEM headers and attempt repair an exhaust leak. Not sure if they cracked or just started leaking. Previous owner put a gasket to the head. I might try to run without a gasket and hope nothing is warped. Are there gaskets to the Y-pipe? Or metal to metal there too?

If I remember correctly the heat shields are tack welded to the headers. If the headers need welding, do you guys reinstall the heat shield afterwords?

 

[earlbrown]

The X-over pipe is metal to metal. Put a smear coat of silicone on both faces (make sure it's 02 safe) and let it 'skin over'. Then get all four bolts started and pulled down evenly but not clamping yet. Give it a couple more minutes, hole the pipe in the right place relative to the pan and TC shield then run them down. Use your finger to make sure the clamp is parallel with the exhaust flange.

On the headers, same thing. Semi dry RTV on both faces (just a skim coat, not a worm),let dry then install. Start all the bolts by hand and give them another minute or two then run them down evenly. With the header make sure you don't scrape the flange against the head and displace the RTV. If you do, pull it out (giggidy) and start over.

 

[TurboBuRick]

Always great advice from Earl.

Ideally the head flanges should be trued on a belt sander.

Rick

 

[earlbrown]

I'd rather start with a slightly warped flange than a belt sanded flange. There's too many leading edges on a header flange to expect a sanded finish to actually be flat.

It's only about a foot long and get's pulled down with 6 3/8th's bolts. That's some serious clamping pressure for something so short.


If I had one warped so bad RTV wouldn't seal it, I'd cut the flanges between each pipe. The one stock header I put on the surfacing machine was a NIGHTMARE. It made SO much noise, took forever, and beat the crap out of the cutter. Never again.

 

[TurboBuRick]

I would still rather take take my chances on a flange that has been somewhat trued on a belt. Agreed that in some cases it will never get perfectly flat but it will be flatter than it was.

Definitely not going to play nice on a surface grinder.

 

[earlbrown]

Oh, lord. I'd never try it on a surface grinder. My right are would be even larger than it is now!!!



On of these days I'm going to put a belt sanded head or diesel manifold on the surfacing machine and make a video of a dial indicator running across it. That should get people off the idea that a belt sanded finish is nowhere near flat.


Anyone in the shop can tell when I find a belt sanded head on the machine. I say the work "fuck!" really loud. Because my time on the machine just tripled or quadrupled.

 

[TurboBuRick]

LOL! Yea i hear you there. Definitely don't want to be belt sanding heads.

 

[626gn]

If I had one warped so bay RTV wouldn't seal it, I'd cut the flanges between each pipe.

^^^This

 

[ITSAV6]

My friends turbo mustang couldn't keep header gaskets. Got him to get copper gaskets and we filled the "O ring" imprint around the ports with high temp copper rtv and let it skim over. So far so good. We figured with the rtv in the groove it would keep more pressure and help it seal better. I did the same thing with my header to turbo.