Exhaust Leak

[homer]

This is my first post as I have recently signed on to forum. The info on this site has been extremely helpful during my build--thanks to all. I need some advice on how to fix an exhaust leak that is coming from the passenger side where the header meets the cylinder head. I have a SA406 and have recently installed a metal/paper gasket to replace a blown felpro gasket. Bolts are tight and the leak only occurs on the second exhaust port from the front of the engine. Any suggestions would be much appreciated.

[Brent]

I would install a new gasket and put a bead of Ultra-Copper High Temp RTV on the head,gasket, and header flange.

Brent

[Tony Radford]

I went so far as to mill out copper gaskets with a dremmel tool. Major pain, but they don't blow.

427SC, Torch Red / white stripes
427 Windsor Stroker from Southern Automotive
Delicious example of Beauty + Power.

[pgermond]

Homer,

If it were me, I would go w/Brent's suggestion first. There isn't a lot of room, and it is the less painless of the two options suggested. Personally, I live in fear of an exhaust gasket leak so I have been diligent about tightening the header bolts. Do you have iron or aluminum heads?


Phil

427 Roadster, #4279436
Southern Automotive FE
3:31 and Toploader

Roseville (N.Cal)

[homer]

thanks for the help =- I have iron heads -- seems like I need a bit more thickness than a single metal gasket -- the felpro that was on prior seemed to be ok on the new trouble spot -- I think I will try bonding two gaskets together with the copper rtv sealant and see what happens

[Brent]

Homer,
I would not think you would have a surface in that bad of shape to require two gaskets.
But, If you are going to sandwich two gaskets together here is the trick:
Take aluminum sheetmetal and trace one of the header gaskets out on it. Cut the metal to exactly reproduce the gasket. RTV both sides of the aluminum shim and the inside of both gaskets and place them together. Place this assy. in a vise overnight and them install the next day. Works great!!!

Brent

[rdorman]

Sounds as though the header flanges are not 'flat'. Next time you take the header off take a good straight edge long enough to go between all four and check. If they are not, make them so. Then go with one of the good gasket suggestions.

Would safety wiring the bolts help the situation? Any one?

Thanks
Rick

[pgermond]

Yeah, safety wire may help a bit..... but I have a hard enough time getting my paws in there to tighten up the bolts let alone mess with safety wire [xx(]

Phil

427 Roadster, #4279436
Southern Automotive FE
3:31 and Toploader

Roseville (N.Cal)

[eliminator]

Safety wire will not help the problem defined, it does sound like the header flange is warped some. I wouldnt want to be the one safety wireing those headers, plus if the bolts are not pulling the header down flush with the heads the safety wire would not help.

Rick

[homer]

The high temp copper rtv and a gasket did the trick -- turns out I had a small amount of the old felpro stuck on the header and didnt see or feel it until I removed the header completely from the car (extremely tough to scrape off) -- thanks for all the help and info

[Brent]

Good to hear.
Headers have always been and will always be a pain in the a$$.

Brent