Meganf

I used a wire brush and put the valves on a drill press. The margins are okay but the faces seem a little worn/burnt?

RLXXI

See that thick lip on the edge of them? You should be able to grind them down to a smooth finish that will seal with the seats, when the valve gets a knife edge or are bent is when replacement would be required.
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Meganf

Thanks for the reply. The lip as in the margin? Should I grind with sand paper? Maybe 400 grit?

Manuellabour247

You can have them professionally cleaned or take your time doing it. You don't want to gouge them. I would start off with 400 grit and some sort of lubrication like cutting oil. WD-40 won't cut it. Just take your time and clean them to where you can start to see the metal below the coke, then switch to a finer grit and so on. I would personally finish with 1600 or better to make sure there are no gouges. You don't have to press really hard, but it'll take a while if you do it yourself.

Meganf

Well, I got lots of time and sand paper. Just to be clear, this is the area/surface I want to grind?

Manuellabour247

That's the valve seat, and yes that's the important area. I'm OCD when it comes to stuff like this so I'd have everything polished. Like I said, it's not that you need to put a lot of pressure on them, just remove the coking. While the valve is a fairly hard metal, it can be gouged. Then your valve will not seat properly. That's why I recommend oil and fine grit sand paper all the way down to a polishing sand paper like 1600+ grit. You shouldn't see any swirl marks or gouges if don't correctly.

Meganf

Understood. Thanks a bunch for the input.

RLXXI

What Manuel said, the biggest thing you want is to make sure your getting a good seal between the valve face (area you're pointing to) and the valve seat on the head. I've only ever used a pro valve/seat grinder and some lapping compound, easiest way to check that they seal is to fill the port with gasoline and see if it leaks out. No leakage = good to go.
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Chris_1

iTrader: (1)

Read up a bit on 'lapping valves". You'll want some valve lapping compound and a little suction cup type 'valve lapping tool'.
That's to do the final seating (matching) of the valve into the seat in the head.
That helps make the valve exactly match the seat that it seals against on the head.
By the time you get the 2 mating surfaces looking good and fitting tight your valves will seal way better than they used to.

Meganf

Thanks for all the input. I already watched some videos on valve lapping. Went out today and picked up some compound and a valve lapper tool. Having trouble finding cutting oil. Finally ordered some online.