Jan 04, 2012· Help, Black & Decker Valve Grinder. Discussion in 'The Hokey Ass Message Board' started by ArizonaBill, Dec 4, 2011. Joined: Aug 29, 2010 Posts: 89. Profile Page ... It has the fixture and stone for grinding the valve stem tips, too. that big knob between the stones at top, should be the coolant control I think. F&J, Dec 4, 2011.