I tweeked a head and pushed out a head gasket after losing my water pump last year. Sent the heads over to Dwayne Porters for a freshened up and to get straightened out. During the process discovered the exhaust valves were all pitted up and had to be replaced. The heads only had 123 runs on them since last rebuild. The valves were Manley extreme duty. The motor is a 572, 440-1 headed, world aluminum block with a tunnel ram and a pair of Pro-Systems 1050's. The compression is 14 to 1. The motor dynoed at a little over 900 HP and 800 TQ when I was running a pair of 750's and a smaller cam. I also use Sunoco Supreme race fuel. Timing is at 34 Degrees. Jets are 90's all the way around. Dwayne has a number of other Chrysler guys around here that are running similar stuff, i.e. compression, cubes, cam. However, they are not experiencing the same valve issues. The only difference is the gas. All the other guys are using VP. I have another buddy that runs a 580 cu.in. Chevy that has the same pitted exhaust valve issue. He also has been using Sunoco but, the Maxima grade from a different vendor. I posted on tech talk and didn't really get much feedback. It seem's like if it was a fuel problem more people would be having issues. What do you guys think? Any one else had this problem? Jim T.

I saw pitting on my exhaust valves in my 426 M.W. Stocker years ago when you could still buy 130/145 avaition and when it went away I continue to used 115/130 avaition. I pulled the motor apart for freshening and saw the pitting, my machinest blamed the fuel, not intended for high RPM. I switched to a race gas for cars and never saw that pitting again on the intakes or exhaust valves or seats I would switch fuels to some that works good for the other local racers Make sure the seats in your heads are intended to be run with the type of exhaust valve your running

I have same compression as you smaller motor timing at 38 B1 orginal head no pitting on my exhaust valves and same sunoco supreme. I would say your compession maybe higher than 14-1

Thanks Cab, that's what my next move is going to be. I am hoping to find others having similar issues. When I posted on another race site didn't receive much response. I felt that if fuel was issue that I would have more negative comments.