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STAFF

BACK ISSUES

by Wayne Scraba

Water pumps are pieces of equipment most racers take for granted. After all, they certainly aren't very byronic or in the same colorful league as something like a new intake manifold or a fresh camshaft grind. Part of it has to do with the simple task assigned to a pump: It must move coolant in and out of the engine. Period. Sure, you can bolt on an aluminum pump and shave some pounds off the nose of your race car, but that's about it.

Of course, in drag racing, the vast majority of water pumps are driven electrically. Our engines only run for a brief period of time, and we're not after endurance cooling. Drag race engines also have a need for additional cooling once the engine is shut off, and because of that, electric water pumps and electric water pump drives have basically become standard equipment on normally aspirated drag race engines.

Unfortunately, most people tend to view pumps as a necessary evil and simply pick the cheapest, most convenient piece of equipment that will get the job done. Is this correct? Several aftermarket manufacturers looked at the situation and collectively didn't think so. More than a few racers are giving pumps a second thought, too. For example, Meziere Enterprises threw its 15-plus years of engineering and manufacturing resources behind, of all things, water pumps. Why would a fledgling racing parts manufacturer be interested in moving coolant? Simply, they realized that there's power lurking inside the cooling system, and if the power could be exploited while improving engine reliability, then they might be on to something. With this in mind, Meziere used CAD/CAM and computer analysis to help design an electric water pump that has proven superior in flow volume and pressure output.

The Meziere brothers looked at what was available and made note of the shortcomings of today's water pumps. According to the Mezieres, their research indicated that some direct-drive electric water pumps had marginal flow rates and, because of their seal housing design, were prone to leakage. At the same time, their new pump design needed to have some sort of adaptability to countless engine-chassis configurations that make up drag racing fields. Given this situation, they decided to engineer their electric water pumps from a clean sheet of paper.

Using CAD equipment, the new pump configurations were contrived from the onset with the drag racer in mind. Flow rates were considered during the design of the body, and so was clearance around common racing hardware such as most camshaft belt drives, blower drives, and front-mount distributors. In the process of creating the pump body, Meziere Enterprises also considered the need for an efficient, hydrodynamic body and impeller configuration. After all, the real purpose of a water pump is to physically pump coolant through an engine.

Coolant flow
Just how important is the flow of coolant? Edelbrock was another company that realized water pumps might provide a path toward more power and improved reliability. When Edelbrock decided to probe that theory, it contracted Ed Pink Racing Engines to put one of its new water pumps to the test on a 355-inch NASCAR Winston Cup Chevrolet engine. Test criteria included cylinder-block water pressure, total pump flow, and side-to-side water-pump flow balance. During testing, the Edelbrock pump was tried against a heavy-duty Chevy aluminum racing pump and another aftermarket pump.

Using a specially constructed test apparatus, Pink first measured the flow characteristics from both sides of the engine. The system effectively divided the small-block Chevy cooling system into two separate parts. Using sophisticated turbine flow meters, the coolant flow was measured from both the right and left cylinder banks. Pressure transducers were also located in the lines near the flow meters so that side-to-side block and heated coolant flow pressure could be monitored and recorded for each water-pump test.

The Victor Series pump achieved almost 3psi more pressure than its nearest rival. The total flow from the Edelbrock pump exceeded 11.5 gallons per minute more than a competing pump. It also achieved 3.1 gallons per minute more flow than the factory Chevrolet racing pump. According to Pink, you don't have to turn the pump as fast to maintain the same cooling efficiency level, thereby reducing parasitic power losses from the water pump.

Water-pump flow balance (side-to-side) testing showed that the Victor Series aluminum water pump was within one-tenth of a gallon from each side of the engine compared to one test pump that varied by as much as 2 gallons per minute per side. This reduction in side-to-side cylinder-head temperature allows a racer to tune the engine closer to the edge for more power.

Part of the pumping equation has to do with the internal paddle wheel found inside a water pump. Instead of sticking to the traditional stamped-steel paddle-wheel arrangement or using a rubber-vane system, Meziere Enterprises decided to construct a billet impeller and pump vein assembly. By paying attention to wheel shape and, of course, the deflection of the vanes under pressure, the Meziere brothers also found they could provide substantially higher pump pressures over the more conventional stamped impeller. Testing has shown that the Meziere paddle-wheel design will flow 32 gallons of coolant per minute in a free-flow state.

Pumping losses
To drive their pump, the Mezieres developed a couple of options. The primary drag race setup is based around a large, built-in electric direct-drive, 12-volt pump motor that only draws 6 amps of current. In most drag racing applications, you only have so many amps of power to work with, and if the race car in question is operated without an alternator (most are), then it's a case of diminishing returns. The battery (or batteries) will discharge during a lap down the quarter-mile, and all electrical equipment will be affected, including the water pump. In the end, the less amperage draw, the better.

In a related issue, many drag race cars incorporate batteries with more than 12 volts — 16-volt systems are common. Recognizing this fact, the Mezieres designed two voltage motors for their pumps. One works on 12 volts, and the other is designed for 16-volt and higher applications. Internally, all the pumps incorporate an upgraded armature with a large 1/2-inch-diameter stainless-steel main shaft. The face seal is ceramic and is aligned with a high-quality bearing set. The integral bearing/seal housing design eliminates seal leakage due to misalignment.

Another neat feature is a front access plug. Once removed from the center of the electric motor, you can insert a hex key in the nose and manually rotate the pump fore and aft. Why is this important? Pretend some contaminants enter the impeller and jam it. Instead of completely field stripping the pump, this access port allows you to quickly solve the problem by manually rotating the pump fore and aft to dislodge the foreign material.

The little hardware
In the case of the Meziere pump, the inlets are sold separately. The reason for this was the wide variety of hose diameters and hose types used in drag racing. Currently, inlet fittings are available in the following sizes from Meziere: 1 1/4-inch, 1 1/2-inch, or 1 3/4-inch hose; 12 A-N, 16 A-N, and 20 A-N line.

Typically, a pump such as the big-block Chevy model shown in the accompanying photos tips the scales at 5.5 pounds. All hardware is stainless steel, and each pump is fully rebuildable and easily serviced. Meziere pumps are available in a wide array of applications, including configurations for big- and small-block Chevys, a special conversion pump for 1993 and newer LT-1 small-blocks, big- and small-block Mopars, big- and small-block Fords, Buicks, Pontiacs, Oldsmobiles, and GM DRCE race blocks. A remote pump is also available for special applications. Other manufacturers offer similar pump availability.

As you can see, even in a seemingly simple application like a water pump, it is possible to build a better mousetrap. By creating internal-pump water passages with equal volume and a unidirectional shape and working within existing mounting bolt spacing, flow can be increased. In short, "ported" water pumps are now available. Well-shaped cross-sectional passages flow more coolant at a higher velocity but at a lower rpm. In the end, this produces a much more efficient component.