AliveAgain
Member
I just put my stock head together after lapping the valves in. I have two questions that I hope you performance people can help. The exhaust port seems to have a slight hump and then a nice size dip to meet the opening for the exhaust pipe connection. On my sport bike, it is more of a smooth elevated flat surface on the bottom section. The Harley port looks like the gases will start tumbling before the first bend of the exhaust pipe. Won't this hamper the flow and scavenging effect?
Second question concerns the valves. They don't even look like multi-angled seating faces and actually have a lip just past the seating face on the valve. I thought that reduces flow. On any head that has been reworked for better breathing, do they address these issues or is there some reason for them to be there?
Second question concerns the valves. They don't even look like multi-angled seating faces and actually have a lip just past the seating face on the valve. I thought that reduces flow. On any head that has been reworked for better breathing, do they address these issues or is there some reason for them to be there?