[jim_howard_pdx]

MAN YOU GUYS CRACK ME UP

LOTS OF OPINIONS VERY LITTLE FACTS

Lets start with the water pump and then move on to the radiator fan issue. A water pump will suceed or fail on its flow capabilities. The water pump basically changes flow volume based upon engine RPM and this is NOT OPTIMUM. Worse, at high RPMs the water cannot flow optimally and then it CAVITATES. This means at upper RPMS your water pump may not be flowing water at all.

So why do people buy high flow water pumps, not because they push more volume. THEY TYPICALLY DO NOT. They simply CAVITATE less at higher RPMS.

An electric water pump, properly configured will provide ideal coolant flow at a continuous level that does not alter with RPM. This is why every serious racer uses one. THEY DO NOT CAVITATE EVER!

Why not use one on a street engine? If you are in colder climates you want your coolant to heat up and help with fuel atomization. An electric water pump might actually make cold weather performance suffer. If you are in a mild climate use the electric water pump.

Why do the manufacturer's stick on a label saying for racing only? Because electric engines are subject to lifetime service rating. They do not want to be sued by people putting these on a motor home diesel and running 800 miles per day.

Now for the radiator fan. All fans have pretty much the same issue. How much airflow do they provide at idle and in average traffic speeds. Most performance cars came with fans that engage at idle, and spin freely at higher RPM. These clutch fans can be very effective and use very little HP at high RPM.

All fans benefit from having a shrowd that maximizes the volume of air the fan can pull. Ideally, the fan blade should be 1 inch from the radiator NO CLOSER AND NO FURTHER. IT SHOULD BE AT LEAST 1 INCH DEEP INTO THE SHROWD.

If running an engine driven fan blade, go with a six blade flex unit. These are really great. They use up the least amount of HP, unless you are running an optimum clutch fan. If you are still hot, mount a single or double pusher fan in front of the radiator to encourage air flow at idle and low speeds.

If running only electric, run both pusher and puller fans. Run a single big puller and double pushers. THESE NEED TO BE SHROWDED OR YOU ARE JUST KIDDING YOURSELF. An unshrowded fan pulls air from the sides, not through the radiator.

Radiator configuration is also a big factor with cooling. The inlets and outlets should be at opposite corners. This forces the water to flow through the tubes where the cooling actually occurs. If your radiator has an inlet and outlet on the same side, the water pump will pull the water through the least path of resistance.

Now look at aluminum radiators. Why do they cool better? Aluminum allows us to run significantly higher water pressure levels than brass. A brass radiator should be using a 6-8 lb cap to eliminate radiator damage. An aluminum radiator will run a 11-17 lb cap. Double the water pressure and you reduce water temperature.

A proper aluminum radiator will run 30-35 degrees cooler than a non-optimized brass radiator. This is how we keep NASCAR engines happy.

Are you figuring this out now???????

Now you know the physics behind the B.S.
Go forth and beat on the poor Chevy guys!