D13,
Lumps work at all RPM's. They also raise the velocity into the port and across the valve. You can see a restriction in the port with lumps if throwing massive boost at it. But you would need to be in the 450-500 hp area for that.
CNC You did not perform any of the Dyno tests that were done. All were done by Me and help from the local inliner guy's. You did help some with planning. Not financially either. Either way,We did test a performance cam and a head prepped with 1.94/1.6 valves, with and without lumps. The lump head had more TQ across the entire RPM range.
Have covid this week and am feeling better today.
