exhaust leak between head and header

[cobraman428]

I have a very slight (annoying) leak between the head and header gasket. The engine head (exhaust side port) was plained but I should have plained the header before putting it on. Anyhow, now there is a slight leak. I've tried to re-tork the bolts. To pull the header requires raising the engine..dont feel like going there if I dont have to. Could I double up the gaskets to take out the slight imperfection or has anyone heard of remflex gaskets or any other suggestions would be appreciated.

[Ronbo]

Try the Percy's carbon gaskets, Summit has 'em.

http://store.summitracing.com/partde...5&autoview=sku

Red RTV is another option. (w/ copper gaskets)

[undy]

I use SCE's soft copper header gaskets with Stage 8 locking header bolts with zero leaks.

[Karl Bebout]

I used doubled HP Felpro gaskets with good results.

[Xavier]

I finally solved my issues with Flatout Copper gaskets with NO EMBOSSMENT. They are one of the few who sell the copper for my engine without the embossment. RTV around the ports and torqued down with ARP 3/8" head bolts did the trick.

[OCCOBRA]

I too had a header leak on my 427 FE. Tried all the available options including the "soft Copper". Each time i would think I had problem solved but leak came back. Finally heard about Rimflex. Gave them a try and leak has never come back !!!!!

[RICK LAKE]

cobraman428 I use a double gasket of the cheap Felpros or Mr Gasket ones. Add a thin coat of Hi temp RTV from Permatex on both sides. Tight the bolts together starting at the ends. Do the final torque spec from the middle ones out both ways. I slot the 2 ends so the gasket drops in with the end bolts on. If you have a problem with this get longer bolts and work from the center out. When done, let the RTV setup for 12 hours, don't fire up the motor until this time. Also have car outside and not in garage, bad smell, and some smoke. Do a couple of 5-10 runs and let cool off, no full throttle runs. You you keep loosing gaskets, you could have one of 2 problems, either the surfaces are not flat on the header flanges or too much back pressure in the exhaust. Check the holes in the flange of the header to clearance of each bolt to the hole, there should be about 1/8 of front to back play. If not, this will bind and pinch the flange. This could cause it to warp enough to also cause gasket failures again. Try and check the flange with a straight edge piece of steel and see if everything is good. Rick L.

[danc30]

Remflex good......

[Caustic_Cobra]

At one time, I too was in your position with the header gaskets. I got a set of Remflex (cost a little more) and have never looked back. I forget what the crush factor was, but again they have worked great for me. I don't think I'll ever go any other way in the future.

[danc30]

Remflex really good.....

[r67cat]

What up with the "Do not click this?"

[Michael C Henry]

I used the copper gaskets and the Stage8 bolts . As I remember (A) to the original part number made the bolts a
1/4" longer to take advantage more of the threads available in the alluminum heads and I have the CobraJet heads which have both bolt patterns full sized car and truck (over and under) and Mustang -Fairlaine (in front and back) of each port. With the ends of the header flanges bobed I have 14 bolts per side all tightened and locked. The center two bolts on each side had to be wired because the locks wouldn't fit against the header tubing.