Originally Posted by Eric64
Do I need to connect the heater lines either in a loop or can I just plug the water pump and the manifold? I do not have a heater in the car and didn't know if a loop was need to cool properly. It's an Edelbrock performer manifold if that makes any difference. Thanks
If the engine is running a thermostat, it should have the heater bypass connected. It was intended by the designers as means of keeping coolant flowing when the thermostat is closed to prevent local hot spots from forming and to keep the pump from cavitating.
There is a small bypass built into the passenger side of block which everybody plugs under the mistaken belief that this forces more coolant thru the pump. The purpose of this bypass is to balance the left and right bank temps because the pump has a higher output to the passenger side than the drivers (a function of impeller rotation direction). Plugging this further exacerbates the operating temp differential between the left and right sides of the engine. This passage is not intended to provide a substitute for the thermostatic bypass, it simply isn't large enough for that. You'll find many Hot Rod books where the authors tell you to plug this passage in one sentence, then in the next tell you to build a dam to partially plug off the pump's flow area into the passenger side cylinder bank. Like duh, there's a clue in here about the purpose of that passage.