Due to the accident my bike is already down for the forseeable future. While i'm waiting on parts, I'm considering all of my options. These heads have already been ported and the combination yielded a great running/well mannered 131/136. My question is this. How much is there to gain from going to oversized valves? Is it worth the risk of potentially screwing up the port ratio? $$$ is not the issue here because I can get this done for the cost of parts.

 

What do the heads flow?? You might want to talk to WFOLarry..

 

The intake throat ratio with stock valves is larger than optimal on 110 heads according to some highly respected head porters. Fixing it with a little bigger valve should only help not hurt anything. I also think at 10.8 and 117 cubes you’re undercammed if the 590 is still in there, I’d retard it 4 degrees if it’s the PS2 version. I’d also port the SE58 throttle body. You should be a lot closer to 140hp than 130 if the heads and pipe flows it, and not lose much if any torque just move to the right a little. And run cooler. Thats how it see it but I’m a nobody, just mess with my own bikes a lot.

 

Ok thanks for the responses guys. I took everything apart and found a crack in the forward exhaust valve guide bore. I ended up sending the heads and a NOS set of SE pro cylinders to T-man to let them handle it. They're going to fix the crack, give me 2.1 intake valves and cut the chambers to match their 20* pistons.