Exhaust Header Rusty Mating Surface

[Qiko]

My first time trying to swap exhaust headers. I have a F22A4 exhaust Header but the mating surface to the cylinder head is extremely rusty.

There are bulges, pits, and dips all over. I tied to smooth it out with a utility blade but can still feel them.





Is this normal or should I toss it?

Thanks

[oyajicool]

if it was mine, i'd use a flat file to take off high spots. if i had a belt sander, i's use that instead.

make the surface reasonably flat and re use the manifold with a new gasket.

[sonikaccord]

I'd use elbow grease and scotch brite...or electrolysis

[cb7 calling]

Spray glue a piece of sandpaper to a sheet of mdf likely the first choice for flatness and grab the header and start sanding until shiny. Maybe start around 100 finish at 200. Maybe use rtv copper around gasket and skip the sanding. Or do both.
Edit...is that carbon build up or pipes misaligned from the flange? I would file/clean that up too.

[Qiko]

great tips, thx

never thought about glue and sandpaper too.

Yup, carbon on the edges of the pipes. Some fell off with gentle pressure. Except for the last pipe on pic 2. Seems the weld went further in.

[cp[mike]]

High-temp Copper RTV Silicone sealant would be perfect for that.

Note: the only areas that matter are the immediate ring surrounding the openings. The rest of the flat face is irrelevant, so rust along the edges and empty spaces between the runners don't matter. From the shiny appearance, it appears your sealing surface is in fine shape. Just clean it up with a little sandpaper and add some copper silicone to fill in the cracks and you should be fine.