I have taken the head off an engine i am playing with and discovered that the head is covered with crud ( i guess its the coke i am de-ing). What is the best method of geting rid. I am inclined to attack it with a wire brush on an angle grinder but i dont want to mess the head up.
ALso
One of the valves has a hunk out of it. Can i replace only one or do i need to replace them all?
I tend to chisel off any hard lumps of carbon with an old screwdriver.
Then go in with the wire brush.
It depends what the deposits are like, soft black stuff come off with the wire brush but hard brown deposits just get highly polished.
But be SURE you don't apply a powered wire brush to the flat surface of the head! Only small wire brush in leccy drill - and keep it in the chamber. One failed valve - means inspect the others closely. The seat with the failed valve will certainly need re-cutting - and highly likely they ALL will.
