Is There An Easy Way to Seal the Area Between the Cylinder Head & Header Flanges?
Sealing the mating area between the cylinder head and the header flange can sometimes present a challenge. If everything works as it should, in theory you should have no leaks. However, in the real world, the exhaust header flange may not seat perfectly (especially in the case of individual-pipe flanges), or certain bolts may be difficult to access, resulting in under- or over-tightening. To help avoid leaks, make sure that all threaded holes in the cylinder head are clean and free of burrs. Apply a thin smear of anti-seize or moly lube to the bolt threads, especially if using stainless steel fasteners, and try to obtain the correct torque values. If you do run into an annoying exhaust leak, you might try a thin bead of Ultra Copper RTV from Permatex on each side of the flange gasket. I’ve had great success with this over the years. After the engine has been run and heat-cycled a few times, and the engine has completely cooled, go back and re-tighten all header flange fasteners. It’s a
