Hi everyone, I was wondering if you can replace bad valve with an existing old one that you know is good? I have a bad exhast valve on my number 4 cylinder and I was just wondering if I can put an old one that I have from my other head in its place?

 

it would be a good idea to lap it in or grind the valve and the seat

 

yep, but valves are cheap.

 

The best way is to get a new valve and have a machine shop recut the seat.

.....the el cheapo way is to use a used valve and lap the valve to the seat (does take some time and skill).

Some links on valve lapping:
http://www.v6z24.com/howto/valvelapping
http://www.public.asu.edu/~grover/willys/valves.html
http://www.tpub.com/content/fc/14104/css/14104_150.htm