110 Fuel Pump: The Complete Guide to Choosing the Right One for Your Engine

If you are searching for a 110 fuel pump, the most important thing to understand is that not all 110 GPH pumps are created equal, and choosing the wrong one can damage your engine or leave you stranded. A 110 fuel pump delivers 110 gallons per hour of fuel flow, which is sufficient for most street performance engines producing up to 500-600 horsepower. However, you need to match the pump type (mechanical or electric), pressure rating, and fuel compatibility to your specific engine setup. Whether you are building a small block Chevy for your weekend cruiser, upgrading a Ford 460 for towing, or maintaining a marine application, this guide will walk you through everything you need to know about selecting, installing, and maintaining a 110 GPH fuel pump.

What Is a 110 Fuel Pump and Why Does Flow Rate Matter?

A 110 fuel pump is rated to move 110 gallons of fuel per hour at free flow, meaning without any restriction from the carburetor or fuel injection system. In real-world driving conditions, the actual flow rate will be lower, typically around 70-88 GPH at normal operating pressures. For example, the Speedmaster 110 GPH electric pump flows 70 GPH at 9 PSI, while the Holley Blue electric pump flows 88 GPH at 9 PSI. This flow rate is adequate for most carbureted engines making up to 500-600 horsepower, but if you are running a supercharged or turbocharged setup that demands more fuel, you may need a higher capacity pump like a 140 or 255 GPH unit.

The flow rate matters because your engine needs a consistent supply of fuel at the correct pressure. If the pump cannot keep up with demand, the carburetor bowls will run dry, causing lean misfires, hesitation, and potentially engine damage. On the other hand, if the pump delivers too much pressure without a regulator, it can overpower the carburetor needle and seat, causing flooding and fuel waste.

Mechanical vs. Electric 110 Fuel Pumps: Which One Do You Need?

The first major decision when choosing a 110 fuel pump is whether to go mechanical or electric. Each type has specific advantages and limitations that suit different applications.

Mechanical 110 Fuel Pumps

Mechanical fuel pumps are driven by the engine's camshaft through a pushrod or lever. They are simple, reliable, and require no electrical wiring. Holley offers two popular mechanical 110 GPH pumps: one for small block Chevy engines (part number 12-327-11) and one for Ford 429/460 big blocks (part number 12-460-11). These pumps have a shutoff pressure pre-set from 6.5 to 8 PSI, which means a fuel pressure regulator is not required for most carbureted applications.

Best applications for mechanical pumps:

  • Street-driven vehicles with stock or mild performance engines
  • Classic cars where maintaining a factory appearance is important
  • Engines that spend most of their time below 6,000 RPM
  • Applications where you want to avoid running electrical wires

Edelbrock also makes mechanical 110 fuel pumps for a wide range of engines including AMC V8, small block and big block Chevrolet, small block and big block Chrysler, Ford 289-351W, 390-428 FE, 429/460, and Pontiac V8. Their 110 series pumps are set at 6 PSI output pressure, and Edelbrock states that an external fuel pressure regulator is not required in most cases.

Installation tip for mechanical pumps: The pump body casting on many mechanical pumps can be rotated to accommodate different plumbing situations. If you need to reposition the lower pump body, be extremely careful because the pump housing is spring-loaded with a heavy diaphragm spring. Always actuate the rocker arm to the full stroke position before tightening the retaining screws to prevent premature diaphragm wear.

Electric 110 Fuel Pumps

Electric fuel pumps offer more flexibility in mounting location and can provide higher pressure than mechanical pumps. They are typically mounted near the fuel tank, below the fuel level for gravity feed, and are wired to the ignition switch or an oil pressure safety switch.

Popular electric 110 GHP options include:

The Holley Blue electric fuel pump (part number 12-802-1) is one of the most recognized performance pumps on the market. It flows 110 GPH free flow, 88 GPH at 9 PSI, and has a maximum pressure of 14 PSI. It comes with a fuel pressure regulator (part number 12-803) and features an externally accessible pressure relief valve. This pump draws only 3 amps of current and is designed for gasoline only. Holley strongly recommends using a safety shut-off switch (part number 12-810) with this pump, and it is not designed for fuel injection systems.

The Speedmaster 110 GPH electric pump offers similar specifications: 110 GPH free flow, maximum pressure of 14 PSI, and 3 amp current draw. It also has an externally accessible pressure relief valve and includes a mounting bracket, but it does not come with a regulator.

The COMP PUMP Series 110 from Mallory is another option, factory set at 7 PSI operating pressure. Mallory recommends a 5/16-inch or larger fuel line with this pump and notes that a fuel pressure regulator is normally not necessary. This pump is available in both gasoline and alcohol/methanol compatible versions, with some models certified for marine use to U.S. Coast Guard and SAE J1171 standards.

Best applications for electric pumps:

  • High-performance street and strip cars
  • Engines that see high RPM operation regularly
  • Vehicles where the mechanical pump location creates clearance issues
  • Applications requiring higher fuel pressure (over 8 PSI)
  • Marine and racing applications

Fuel Pressure: Why It Matters and How to Get It Right

Fuel pressure is just as important as flow rate. Too little pressure and the engine starves for fuel. Too much pressure and the carburetor floods, waste fuel, and can even damage the carburetor.

What pressure do you need?

  • Most carbureted street engines operate best at 5.5 to 7 PSI
  • Holley mechanical pumps are pre-set at 6.5 to 8 PSI
  • Edelbrock 110 mechanical pumps are set at 6 PSI
  • Holley Blue electric pump has a maximum of 14 PSI, but you must use the included regulator to bring it down to carburetor-safe levels
  • COMP PUMP Series 110 is factory set at 7 PSI

If you are using an electric pump that produces more than 8 PSI, you absolutely need a fuel pressure regulator. The COMP PUMP Series 140 pumps are set at 12 PSI and must be used with a regulator to prevent carburetor flooding. Some Series 140 kits even come with a 3-port return style regulator that requires a return line back to the fuel tank.

How to set fuel pressure:

  1. Install a fuel pressure gauge between the pump and the carburetor
  2. Start the engine and let it idle
  3. Adjust the regulator (if equipped) to the desired pressure
  4. Rev the engine and verify pressure holds steady under load
  5. Check for pressure drop during hard acceleration, which indicates the pump cannot keep up

Fuel Line Size: Don't Starve Your Engine

Using the correct fuel line diameter is critical for proper fuel delivery. If the line is too small, it restricts flow and the pump cannot deliver its rated capacity.

Recommended fuel line sizes:

  • For COMP PUMP Series 110 (7 PSI): 5/16-inch or larger fuel line is recommended
  • For COMP PUMP Series 140 (12 PSI): 3/8-inch or larger fuel line is recommended
  • For Holley Blue electric pump: 3/8-inch NPT inlet and outlet
  • For Holley mechanical pumps: 3/8-inch NPT inlet and outlet

Most performance 110 GPH pumps use 3/8-inch NPT threads for both inlet and outlet. If your existing fuel lines are smaller, you will need to upgrade them to take full advantage of the pump's capacity.

Return lines: If your system uses a return-style regulator, the return line should also be 3/8-inch or larger. COMP PUMP Series 140 pumps with return regulators require a return line from the regulator back to the fuel tank.

Installation Best Practices for Electric 110 Fuel Pumps

Proper installation is essential for safety and performance. Here are the key steps based on manufacturer instructions.

Mounting Location

Mount the pump as close as possible to the fuel tank, at or below the level of the fuel tank pickup. This ensures good gravity feed to the pump inlet. The pump should be mounted in a vertical position with the motor on top to prevent fuel from leaking into the motor housing, which could create a fire hazard. Avoid mounting the pump near moving parts or hot surfaces like the exhaust system. Also, increasing the distance between the pump and the tank reduces pump efficiency.

Fuel Filter Is Mandatory

Always install a suitable fuel filter between the fuel tank and the pump. Mallory recommends a minimum 40 micron filtration to prevent debris from entering the pump and locking the Gerotor. Without a filter, even small particles can cause the pump to fail prematurely. Use a high-quality inline filter rated for your pump's flow capacity.

Wiring Guidelines

Use 14 gauge wire or larger for the power and ground connections. Always disconnect the battery ground cable before wiring. There are two common wiring methods:

  1. Wiring to an oil pressure switch: This provides power only when the engine is running. If the engine stalls, the pump shuts off automatically, preventing fuel from being pumped in a crash situation.

  2. Wiring directly to the ignition switch ON terminal: The pump runs whenever the ignition is on, even if the engine is not running. This is simpler but less safe. Holley strongly recommends using a safety shut-off switch with this method.

Use a 7.5 amp fuse for over-current protection, as specified by most pump manufacturers. A relay kit is also recommended to handle the current load and protect the ignition switch.

Fittings and Thread Sealant

When installing fittings into the pump, use a liquid thread sealant compound. Do not use Teflon tape, because small pieces of tape can break off and get into the pump mechanism, causing it to lock up. Also, do not overtighten the fittings, as this can crack the fuel chamber housing and void the warranty.

Maintenance and Troubleshooting

Electric fuel pumps are generally low-maintenance, but they can fail if not cared for properly.

Common Problems

  • Pump runs but no fuel delivery: Check for a clogged fuel filter, kinked fuel lines, or a failed check valve inside the pump
  • Low pressure: The pump may need cleaning. Internal components like the Gerotor can accumulate varnish and debris over time
  • Noisy operation: Air leaks in the suction line, loose mounting, or cavitation from low fuel level
  • Pump won't run: Check fuses, wiring connections, and the oil pressure switch if wired through one

How to Clean a COMP PUMP

If your pump fails to produce adequate pressure, it may require cleaning. The disassembly process is detailed in the Mallory instructions: remove the two fuel chamber screws, separate the port plate from the fuel chamber, and inspect the flame arrestor screen and Gerotor for debris. Be careful not to drop the Gerotor when disassembling. After cleaning, reassemble with the alignment marks you made during disassembly.

Service Parts

Most quality pumps have readily available repair kits:

  • COMP PUMP brush kit (part number 3146A)
  • Seal/repair kits for gasoline (3165) and alcohol/methanol (3166)
  • Holley Blue pump repair kits are also available

Fuel Compatibility: Gasoline, Alcohol, and E85

Not all 110 fuel pumps are compatible with all fuel types. Check the specifications carefully before purchasing.

  • Gasoline only pumps: Holley Blue electric pump, Holley mechanical pumps, Edelbrock 110 series
  • Gasoline and E85 compatible: Speedmaster electric pump, KEMSO high performance pumps
  • Alcohol/methanol compatible: COMP PUMP Series 110 models with part numbers ending in "A" (4110A, 4141A, 4142A, 4150A)

If you need to convert a gasoline pump to alcohol/methanol or vice versa, COMP PUMP offers seal/repair kits specifically for this purpose. Never run alcohol fuel through a pump designed only for gasoline, as the seals and internal components can degrade rapidly.

Marine applications: If you are using a fuel pump on a boat, look for pumps that meet U.S. Coast Guard and SAE J1171 specifications. The COMP PUMP Series 110 part number 4110M and Series 140 part number 4140M are certified for marine use.

Why You Should Choose KEMSO Fuel Pumps for Your High-Performance Build

When it comes to reliability, performance, and long-term value, KEMSO fuel pumps stand out as a top choice for American car enthusiasts and mechanics. KEMSO offers a wide range of high-performance fuel pumps designed as direct OEM replacements for popular vehicles, including cars, trucks, motorcycles, ATVs, and personal watercraft. Every KEMSO fuel pump is built with precision engineering to meet or exceed original equipment specifications, ensuring a perfect fit and reliable operation.

What makes KEMSO different?

  • High flow rates up to 340 LPH (liters per hour), supporting up to 600 BHP in naturally aspirated, turbocharged, and supercharged engines
  • Bypass valve set at 125.8 PSI, providing consistent fuel delivery even under extreme demand
  • Compatible with both gasoline and E85, giving you flexibility in fuel choice
  • Lifetime warranty backed by USA-based customer support, so you have peace of mind with every purchase
  • Serialized pump body for warranty tracking and quality assurance

KEMSO fuel pumps are ideal for anyone upgrading from a Walbro 255 LPH pump or replacing a worn factory unit. Whether you drive a Subaru Impreza, Honda Civic, Ducati motorcycle, Kawasaki Jet Ski, or Can-Am side-by-side, KEMSO has a direct replacement pump that fits perfectly and delivers superior performance.

Visit the KEMSO website today to find the right fuel pump for your vehicle:

https://www.kemsoracing.com/

At KEMSO, you will find fuel pumps for virtually every application, from high-performance sports cars to heavy-duty trucks and recreational vehicles. Their team of experts can help you select the correct pump for your specific make and model, and their lifetime warranty means you will never have to worry about premature failure. Fuel your adventure with confidence by choosing KEMSO.

Final Thoughts on Choosing a 110 Fuel Pump

Selecting the right 110 fuel pump comes down to understanding your engine's requirements and your driving habits. Mechanical pumps are excellent for street-driven classics and mild performance builds where simplicity and reliability are the priorities. Electric pumps offer more versatility, higher pressure capability, and better suitability for high-RPM racing applications.

Key takeaways:

  1. Match the pump flow rate to your engine's horsepower level. A 110 GPH pump handles up to about 500-600 HP on a carbureted engine
  2. Use a fuel pressure regulator if the pump delivers over 8 PSI
  3. Install a fuel filter between the tank and pump to protect the internal mechanism
  4. Use 3/8-inch fuel lines for best flow, especially with electric pumps
  5. Mount the pump low and close to the tank, with the motor pointing up
  6. Never use Teflon tape on fittings; use liquid thread sealant instead
  7. Wire electric pumps through a relay and fuse for safety
  8. Choose a pump compatible with your fuel type (gasoline, E85, or alcohol)

For the best combination of performance, reliability, and warranty protection, consider a KEMSO high-performance fuel pump. With their lifetime warranty, USA-based support, and broad vehicle coverage, KEMSO gives you confidence that your fuel system will deliver when it matters most.

Remember: A proper fuel system is the foundation of engine performance. Invest in quality components, follow installation instructions carefully, and your 110 fuel pump will serve you reliably for years to come.

For more information and to browse the full selection of KEMSO fuel pumps, visit: https://www.kemsoracing.com/


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