Water pumps are an essential component of your vehicle’s cooling system. Its principal function is continuously circulating coolant from the radiator to the engine block.
For cars with small block Chevy engines, short and long pumps may consider the owners.
Knowing this concern, this article fully compares an SBC short vs long water pump. After distinguishing, you can decide the best way to maintain or repair this component.
Let’s read until the end for all the necessary information.
What Is A Water Pump?
What Does the Water Pump Do?
This component is essential in any vehicle because it keeps the engine cool by allowing coolant to circulate through the car engine block.
In short, a car coolant system maintains the engine, hoses, and radiator at optimal operating temperatures.
If there is any problem with this component, water leakage can happen and make the radiator burst while driving.
Modern water pumps are substantially more durable, yet they can still fail after many years or miles.
Generally, a pump bearing fails, or a leak develops, which can cause major damage to the engine if not repaired. Fortunately, there are ways to predict when your water pump will fail.
How Does the Water Pump Work?
The equipment in your vehicle draws water from the engine radiator and circulates it through the motor back to its radiator, where the cycle will start again.
It ensures that your engine maintains a constant temperature regardless of the weather.
When it goes through the motor, the water from the engine radiator heats up. It requires the pump to return it to the radiator to cool. Otherwise, the engine will overheat.
The engine in most cars turns the water pump’s belt, making the pump’s axle turn.
- The axle is connected to many vanes, which will rotate in tandem.
- The spinning motion provides suction, which draws water from the engine radiator.
If water reaches that pump, centrifugal force causes it to be thrown against its outer walls and down a drain to the engine block.
The water will flow through the engine cylinder heads before returning to the radiator (where the cycle starts again).
So between long vs short water pumps, which one is for you? Scroll down!
What Are Differences Between A Short Vs Long Water Pump?
You can distinguish between an SBC long vs short water pump by 3 factors: car models, the component size (height), and their visual looks.
Although these two are quite similar, carefully looking can help you compare them.
Car Models
Except for the Corvette, which used the conventional short-style pump through 1970, GM used the short option on vehicle applications through the 1968 model year (and 1972 for light trucks).
In 1969, GM began using long water pumps in automobiles and light trucks in 1973.
Height
The best approach to distinguish between a long water pump vs short option is to measure the distance between the gasket surface and the surface of the water pump pulley hub.
Let’s place a straight edge or a ruler across the face of the pulley hub.
A “short” one in the small block is 5-5/8 inches in height. Large block “short” pumps are 5-3/4-inch long (5.750-inch).
Due to engine compartment clearance concerns with a specific 5.795-inch height, the Corvette employed its own version of a small water pump from 1971 to 1982, so keep that in mind as well.
The long pump of the small block measures 7 inches, and the big block long water pump measures 7-1/4 inches (appropriately 7.250 inches).
Several of the later-generation aluminum water pumps with serpentine-belt driving systems also included a reverse rotation pump.
The mounting space for the big block pump is also different, although this can be difficult to discern with the pump off the engine. So always confirm the pump’s “height” is correct for your requirements.
Visual Look (Water Pump Setup And Installation)
Another fast visual check to tell a long water pump vs short water pump apart is where they are attached.
When fitted, the water pump is normally easy to spot since the relationship between its back plate and the engine’s timing cover leaves no room for your hand between the two.
In short water pump installations, the alternator was mounted on the driver’s side of the car engine.
If this component is not attached, you can determine it is a short pump by measuring from the pump’s gasket to the component pulley’s mounting hub surface.
The long water pump looks similar to the short one, but it comes with longer cast “legs” that bring the pump’s primary body away from the vehicle engine.
A long water pump, like a short water pump, may usually be identified by the extra-large space between the pump’s backside and the engine’s chain cover.
The gap is about two finger widths wide, and most people can easily insert their fingers between the engine and the water pump as a simple test.
Short Water Pump Vs Long: Should We Use A Long Pump In A Short Application?
No. Remember that matching and mixing pulleys between long and short pumps can result in misalignment.
Thus, once you’ve determined whether you need a short or long option, be sure to measure the shaft/pilot so you can remount the fan, water pump, and pulley without difficulty.
The size is vital for ensuring the right flow rate and differential head necessary for the application, which are the two most important specifications when building a water pump system.
Flow rate, also known as volumetric flow rate (Q), is the amount of fluid that moves through a cross-sectional area in a given amount of time.
Faqs On SBC Long Water Pump Vs Short
Are Larger Pumps More Efficient?
Yes, larger pumps will be more efficient. Yet, it doesn’t mean your car should use a large, long pump. You need to decide depending on your car engine.
Many medium and larger pumps have efficiencies of about 75 – 93%, and smaller ones often have efficiencies of about 50 – 70%.
Large AC motors, however, approach 97 percent efficiency, and any motor with ten horsepower or more may be configured to exceed 90 percent efficiency.
How Many Types Of Automobile Pumps?
In general, we have 4 types of water pumps, each one adapting to the characteristics of each vehicle:
- Mechanical water pumps: The coolant in this pump collects heat from the cylinder head and engine block and then releases it to the surrounding air via the radiator. Mechanical water pumps are typically powered by timing belts, V-belts, or directly from the engine.
- Variable water pumps: It is distinguished by the ability to vary the flow rate based on the engine’s needs, which is accomplished by a vacuum process. That is, the water pump only operates the cooling system when needed.
- Electric water pumps: This option contributes to lower emissions from modern engines. A supply flow that is independent of the number of rotations of the motor allows for on-demand cooling.
This minimizes the required power, lowering friction losses, pollutant emissions, and fuel consumption.
- Auxiliary water pumps: The primary role of an auxiliary water pump is to assist the primary water pump.
On the other hand, the auxiliary water pump is more concerned with comfort because it is positioned in a bypass hose of the major cooling system and drives coolant to the heater inside the automobile.
What Are The Common Problems Of A Water Pump?
Here are some common problems you might notice:
- If you find a grinding noise (even at idle) coming from the car’s water pump, it could be due to worn-out bearings or a loose bearing.
- Water leakage from the coolant pump is another prevalent issue in automobiles. This indicates that the shaft seal or the gasket between the engine and the pump has failed to keep the coolant inside the engine.
Gaskets or seals tend to dry out, crack, or break with time, causing coolant leakage toward the front of your vehicle.
- Water pumps in automobiles with plastic impellers can shatter and cause vibrations, causing the pump to fail.
- In cold weather, the water in the cooling system may freeze, making the pump’s parts wear out.
- If you have corrosion in your water pump, mineral buildup, or rust, it is most likely due to the use of the incorrect coolant.
- A high-pitched or light pounding noise suggested the water pump pulley was loose. It is caused by a belt snapping due to dryness, which causes the pulley to become loose, causing the water pump bearings to wear out
- You may have noticed fumes streaming out of your automobile when you open the hood. Have your expert inspect the coolant system right away because it isn’t working properly.
How Long Does A Water Pump Last?
Most water pumps’ projected lifespan is 60,000 to 90,000 miles. However, many can survive far longer.
If your car has hit the coveted 100,000-mile mark, you should anticipate the need for a pump replacement shortly.
This cooling system component will occasionally give you indications that it needs to be changed. You can change and fix it yourself or bring it to an auto shop for a replacement.
Conclusion
After this article, you can now distinguish between a short vs long water pump. These two are pretty similar at first look, but please pay attention to their size and how they are installed.
Each option will fit a specific car model to make the best performance.
As a result, you should carefully search or ask the car manufacturer for the right style water pump for your vehicle.