Hey, I'm rebuilding a head, and the exhaust valves have a brownish deposit thats hard as a rock, on the exposed side of the stem and the head. I've been carefully sanding this stuff but man its taking forever!! any way to speed the process up here, or just thank goodness there's only 8 valves? the intakes are just a little black, and the deposits are easier to remove, but not by a ton.
Thanks
G