Pitting in valve

[BP Builds]

Hey Guys, Looking for experience here as this is my first engine build. While lapping my valves for a while, I identified some pitting on this exhaust valve. What do you guys think? Send it? Keep working it? Replace?
The seat looks great.
Gt40p heads.

 

[7991LXnSHO]

I think it needs grinding first, and it might be too small by the time it’s cut. You’ll have horrible calluses before lapping compound alone fixes this.

 

[CarMichael Angelo]

Looks like it might have had water sit in the chamber for awhile while the head was off.

 

[BP Builds]

I think it needs grinding first, and it might be too small by the time it’s cut. You’ll have horrible calluses before lapping compound alone fixes this.

Sorry, but grind how? Could you expand?

 

[BP Builds]

Looks like it might have had water sit in the chamber for awhile while the head was off.

This is actually how they looked when I removed the heads, all 8 look more or leas like this. But i just bought the explorer engine about a year ago, so before that who knows what happened to it.

 

[7991LXnSHO]

Sorry, but grind how? Could you expand?

View: https://youtu.be/sxQcZySsFEw

 

[CarMichael Angelo]

just take the heads to a machine shop and have them perform a valve job. The seats of those valves are too far gone to try and lap them.

 

[7991LXnSHO]

just take the heads to a machine shop and have them perform a valve job. The seats of those valves are too far gone to try and lap them.

Agreed. Even if the valve stem to guide clearance is not too high, using a suction cup on a stick tool to try to lap the valves and seats will either cause blisters (or blindness) long before it addresses the problem. Lapping is just for final seating after the other parts are machined correctly. It’s like using mirror glaze polishing compound over peeling paint. Too much metal is gone.

 

[BP Builds]

Agreed. Even if the valve stem to guide clearance is not too high, using a suction cup on a stick tool to try to lap the valves and seats will either cause blisters (or blindness) long before it addresses the problem. Lapping is just for final seating after the other parts are machined correctly. It’s like using mirror glaze polishing compound over peeling paint. Too much metal is gone.

Thanks, definitely don't have one of those machines, and even if i did, I'd be scared the angle wouldn't be exact.

There is a really good Auto machine shop by my house, I had them polish my cam back to new. The only issue is they are backed up with work, so I'll be waiting a while.