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.
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.
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.
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.
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.
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.