smoking hard out left bank

used to melt a lot in the snowmobiles when I raced when I was a kid temps could change 15 degrees between races . hard to see in pic but the whole ring is there and it still showed over 150 psi on comp test . there is a 1 inch long piece of valve relief missing just chipped down to the ring
no hole . but no nick on valve either , but will have to check it and repolish it , I am sure there is melted metal on it too.