Engine is spitting anti freeze through catch tank

[CHANMADD]

The thermostat slows the coolant down so that it will remain in the radiator long enough to cool......

[scottj]

If I'm understanding, your cap is on the hi-pressure side of the system. The cap should be on the low pressure side of the system. When the cap is on the hi- pressure side, pump pressure can cause the cap to relieve. When on the low pressure side it will only relieve when system pressure reaches the cap rating.

The thermostat is there to maintain minimum coolant temp.

Everyone in the industry, from manufacturers of radiators to hi-flo water pumps, believes that higher flow rate results in more efficient cooling.

[scottj]

There's a lot of good info here: Stewart Components

[Z-linkCobra]

Im not a big fan of hi flow water pumps and have never had good luck with them myself. With the race cars we always slowed the water pump down and further restricted the water flow with reducers in the top hose.

Water rushing through the block at a high rate of speed is also rushing through the radiator. like Chanmadd said...sooner or later you will exceed the waters ability to absorb heat and the radiators ability to remove it.

Just my two cents worth from my experience. I know on a big block ford if you take the t-stat out...its going to run hot. Small blocks are a little more forgiving.