The fuel pump size really varies depending on the grade of fuel deliverability and the type of engine application. One of the main differences in fuel pump sizes pertains to their flow rate, normally measured in LPH. Smaller ones-those that come in conventional passenger vehicles-deliver a power of 90-130 LPH, which is good enough for mediocre power demands of engines. The high-performance or modified engine-around turbocharged and supercharged engines-require larger pumps with a capacity of 200-255 LPH to handle the high consumption of fuel. That size allows for an increase in flow rate, which can keep up the fuel pressure at very high RPMs.
In physical dimensions, the size of the fuel pumps also differs, with the manufacturers designing the pump to fit a certain fuel tank configuration. In-tank fuel pumps are normally small and cylindrical, compact so that they may fit inside the fuel tank without occupying much space. Normally, these pumps measure 4-6 inches in length and 2-3 inches in diameter, allowing it to install efficiently inside the tank. This way, it keeps the pumps cool and reduces the noise. On the other hand, an external fuel pump is bigger; mostly greater than 8″ inches in length and larger in diameter to take up more flow. External pumps are common in high performance applications where cooling and access are cardinal issues. This is because they stay outside the tank and hence dissipate heat well.
Another difference is the capacity of the pressure, which directly affects performance, especially in the fuel system. Smaller fuel pumps tend to operate within lower pressures, usually in the range of 30-80 psi, which is ample for most naturally aspirated engines. The larger ones can handle more than 100 psi and are necessary for high-performance engines that require consistent and high levels of fuel pressure. For this reason, larger, higher-pressure fuel pumps are very often recommended for those engines which have higher power output by technicians; smaller pumps risk fuel starvation and possible engine damage.
The size of the fuel pump can also contribute to weight; some small fuel pumps can weigh as little as 0.5 pounds, while some larger, more high-performance pumps can be upwards of 2-3 pounds or more. Although this weight difference seems very slight, in performance vehicles it is an important consideration for shedding unnecessary weight. The right size of fuel pumps varies based on a balancing act of variables like demands on the engine, space constrictions, and the requirements for fuel flow to guarantee effective operation.
As Carroll Shelby, a legend in automotive once said, “Performance is all about power and precision.” A proper-sized Fuel Pump amplifies both for the smooth running of a vehicle. Check out Fuel Pump for more information on fuel pump sizes and good brands.