March 809 Pump Head Inside Diameter

[JVD_X]

I just measured the inside diameter of the threaded ports of the march pump and they are basically 24/64ths. So - less than the 1/2" ID cam locks and quick disconnects we have been using.

I recently did switch to true 1/2" couplings and saw a drastic improvement but I was wondering if you guys think that drilling out the ports might also help.

 

[JVD_X]

Follow up...

I went ahead and drilled out the ports on one of two March pumps I own. Unfortunately, the diameter can't be as large at 1/2" because there is a little screw which needs a little indent on the outside of one of the pump ports so it can properly screw into the body.

However, I have noticed a slight increase in my flow. The bore was clean and scratch free.