Gen1Pat
Well-Known Member
It's not the valve that gets all the angles machined into it. It is done to the valve seat in the head itself. Typically, a 3 angle valve job intails grinding the valve seat with a 60* stone, then a 45* degree stone, and lastly a 30* stone. Add two more angles of either smaller or larger degrees in there and the intake charge and exhaust gases flow in/out of a less abrupt curve going to the valve (intake) or from the vlave (exhaust). The angle of the actual seat surface is supposed to have a certain affect on performance, too.
