I have a 1932 Ford Coupe that has a 340 Dodge motor. I need to know how much clearance to allow between the water pump pulley and radiator.
I am using an electric fan. I want the motor to be as far forward as possible for firewall clearance.
well actually you dont want to put the motor as far forward as possible... you want to put the motor as close to the fire-wall as you can! this will give you a center of gravity further backin the car, giving you:
Better weigth transfer during acceleration, Better cornering,
Better exhaust to frame clearence,
And lastly unshrouding the radiator equaling better cooling
I used a "Cooling Components" combo shroud / electric "puller" fan on my '31 Ford (deuce shell and a Walker Radiator).
I bolted the fan / shroud up to the radiator and left a minimal amount of clearance between the water pump pulley and the electric fan motor, an inch is plenty. I am running a 350 Chevy, the water pump pulley is very low and nearly clears the bottom of the fan motor.
If you haven't bought your radiator, shroud and fan yet you would be better off doing so now. It will save you a lot of headaches mocking everything up now.
When you decide on the configuration you want, be sure to leave enough room to change a belt, water pump, or anything else you may have to do without having to do anything extra. Sometimes this is impossible, but keeping your "Maintenance envelope" will save you some time and aggravation later. Good luck!