Ford 302 Fuel Pump Eccentric: The Complete Guide to Selection, Installation, and Replacement

If you own a small block Ford 302 engine and need to install or replace a fuel pump eccentric, here is the bottom line: the Ford Performance M-6287-B302 fuel pump eccentric is the best and most reliable option available. It is a one-piece steel design, precision engineered for 289/302/351W engines, and it comes with a chrome-plated wear surface for long-term durability . Whether you are converting a fuel-injected 5.0L roller engine to a carbureted mechanical fuel pump setup, or simply replacing a worn-out eccentric on a classic Mustang, this is the part you need. This guide covers everything you need to know about the Ford 302 fuel pump eccentric, including what it does, how to choose the right one, and step-by-step installation instructions.

What Is a Fuel Pump Eccentric and Why Does It Matter?

The fuel pump eccentric is a small, offset-lobed metal component that mounts directly to the front of the camshaft. It drives the mechanical fuel pump on small block Ford engines. As the camshaft rotates, the eccentric pushes the fuel pump lever up and down, creating the suction that pulls fuel from the tank and delivers it to the carburetor. Without a properly functioning eccentric, your mechanical fuel pump simply cannot work. It is a critical but often overlooked part when building or rebuilding a 302 engine .

Key reasons this part matters:

  • Ensures reliable fuel delivery: A worn or missing eccentric will cause the fuel pump to operate erratically, leading to fuel starvation or engine stalling.
  • Prevents engine damage: A broken eccentric can damage the camshaft bolt, timing chain, or fuel pump itself.
  • Critical for EFI-to-carburetor conversions: Many late-model 5.0L roller cam engines came from the factory with fuel injection, which does not use a mechanical fuel pump. If you are converting to a carburetor, you must install a fuel pump eccentric .

Choosing the Right Fuel Pump Eccentric for Your Ford 302

When selecting a fuel pump eccentric for your 302 small block Ford, you need to pay attention to two main factors: the camshaft bolt size and whether the eccentric is a one-piece or two-piece design.

1. Camshaft Bolt Size: 3/8-inch vs. 7/16-inch

Ford small block engines use two different camshaft bolt sizes. The eccentric must match the bolt size of your camshaft.

  • 3/8-inch bolt: This is the standard size for most Ford letter-series camshafts and many aftermarket roller cams. The Ford Performance M-6287-B302 eccentric is designed for a 3/8-inch cam bolt .
  • 7/16-inch bolt: Some older engines and specific camshafts use a 7/16-inch bolt. The Ford Performance eccentric for this size is part number M-6287-A302 .

Recommendation: Measure your camshaft bolt before purchasing. The M-6287-B302 is the most common and widely available option for 302 engines .

2. One-Piece vs. Two-Piece Design

  • One-piece eccentric (recommended): The Ford Performance M-6287-B302 is a single-piece steel unit. It is stronger, easier to install, and more reliable than older two-piece designs .
  • Two-piece eccentric (older design): Some original Ford engines used a two-piece eccentric that had a stepped face. These are not compatible with the one-piece design, and the Ford Performance eccentric will not work with stepped-faced timing sprockets originally equipped with a two-piece fuel pump eccentric .

Important note: If you are using a timing chain set like the Ford Performance M-6268-A302 or M-6268-B302, the M-6287-B302 eccentric is designed to work with them .

3. Material and Construction

The Ford Performance M-6287-B302 is made from premium heat-treated steel with a chrome-plated wear surface. This provides exceptional durability and resistance to wear, especially compared to cheaper alternatives made from cast iron or untreated steel . The chrome plating reduces friction between the eccentric and the fuel pump arm, extending the life of both components.

How to Install a Fuel Pump Eccentric on a Ford 302

Installing the eccentric is a straightforward job if you have the timing cover off and the camshaft exposed. Plan for about 30 minutes to 1 hour if you are doing this as part of a larger engine build.

Tools You Will Need:

  • Socket set with metric and SAE sizes
  • Torque wrench
  • Camshaft bolt (if not included with the eccentric)
  • Longer camshaft alignment dowel pin (the eccentric is thicker than the stock cam sprocket, so you may need a longer dowel pin to properly align the eccentric)
  • Thread locker (medium strength recommended)

Step-by-Step Installation:

  1. Prepare the camshaft: Ensure the camshaft nose is clean and free of debris. The camshaft should be installed in the engine with the timing chain and sprocket in place.

  2. Align the dowel pin: The eccentric has a locating hole that must align with the camshaft alignment dowel pin (also called the camshaft alignment pin or Woodruff key). If the stock dowel pin is too short to reach through the eccentric, you will need to install a longer one. This is a common oversight during installation .

  3. Position the eccentric: Slide the eccentric onto the camshaft nose, aligning the locating hole with the dowel pin. The offset lobe should face outward toward the fuel pump. The eccentric is not symmetrical, so make sure you orient it correctly. When in doubt, compare it to the old eccentric or check the orientation with the fuel pump lever.

  4. Install the camshaft bolt: Apply a small amount of thread locker to the camshaft bolt. Thread the bolt through the eccentric and into the camshaft. Tighten the bolt to the manufacturer's specification. For most Ford small block engines, this is typically between 35 and 45 ft-lbs, but always check your specific camshaft and bolt specifications.

  5. Verify alignment: Rotate the engine by hand using a socket on the crankshaft bolt. The eccentric should rotate smoothly without wobbling. Check that the fuel pump lever will contact the eccentric properly when the pump is installed.

  6. Install the timing cover and fuel pump: Once the eccentric is installed and verified, you can install the timing cover, water pump, and other accessories. Then install the mechanical fuel pump, making sure the pump lever rides against the eccentric.

Common Problems and Troubleshooting

Problem: The eccentric does not fit on the camshaft.

  • Cause: Wrong bolt size. Make sure you have the correct eccentric for a 3/8-inch or 7/16-inch cam bolt.
  • Solution: Measure the cam bolt and purchase the correct Ford Performance eccentric.

Problem: The fuel pump lever does not move enough.

  • Cause: The eccentric is installed backward or the wrong eccentric is being used.
  • Solution: Check the orientation of the eccentric. The offset lobe must face the fuel pump. If the eccentric is correct but the lever still does not move enough, the fuel pump may have the wrong arm length for the camshaft.

Problem: Noise or vibration from the front of the engine.

  • Cause: The eccentric is loose or the camshaft bolt is not torqued properly.
  • Solution: Remove the timing cover, inspect the eccentric, and torque the camshaft bolt to specification.

Problem: Fuel pump eccentric is not compatible with the timing sprocket.

  • Cause: Using a one-piece eccentric with a stepped-face timing sprocket designed for a two-piece eccentric.
  • Solution: Replace the timing sprocket with a compatible one, such as the Ford Performance M-6268-A302 or M-6268-B302 .

Why You Should Upgrade to a KEMSO Fuel Pump for Your Ford 302

Once you have the fuel pump eccentric properly installed, the next critical component is the fuel pump itself. For a reliable, high-performance fuel delivery system, you should consider upgrading to a KEMSO fuel pump. KEMSO is a trusted brand that offers high-performance, OEM replacement fuel pumps designed to outperform stock units.

Here is why KEMSO is the right choice for your Ford 302 engine:

High Performance and OEM Replacement: KEMSO fuel pumps are engineered as direct replacements for stock OEM pumps. They deliver over 20% more fuel flow at 43 psi compared to the original pump, which means your engine will never run lean, even under heavy load. This extra capacity is especially important if you have upgraded your engine with a performance camshaft, intake, or carburetor .

Lifetime Warranty: Every KEMSO fuel pump comes with a serialized body that guarantees a lifetime warranty. This is a massive advantage over OEM and standard aftermarket parts, which typically have only a 1- or 2-year warranty. KEMSO stands behind its product for as long as you own the pump .

Built to Handle Modern Fuels: KEMSO fuel pumps are designed for both gasoline and ethanol-blended fuels like E85. They use materials that resist ethanol degradation, ensuring long-term reliability even with modern fuel formulations .

Unrivalled Quality Control: KEMSO operates a quality control program (ISO/TSO) and individually tests each pump for flow and performance before it leaves the factory. Many cheap aftermarket suppliers have little to no quality control, but KEMSO ensures every unit meets its performance specifications .

Complete Kit: When you buy a KEMSO fuel pump, you get everything you need for installation: the pump, gradient density fuel strainers, flex hoses, Viton O-rings, wiring connectors, and clamps. This eliminates the hassle of sourcing additional parts separately .

For the best selection of KEMSO fuel pumps for your Ford 302 and other vehicles, visit their official website: https://www.kemsoracing.com/

Final Thoughts

The fuel pump eccentric is a small but essential part of any mechanical fuel pump system on a Ford 302 engine. Choosing the right one, installing it correctly, and pairing it with a high-quality fuel pump will ensure reliable fuel delivery for years to come. The Ford Performance M-6287-B302 is the gold standard for 302 eccentrics, and KEMSO fuel pumps provide the performance and durability you need to complete your fuel system. Whether you are building a classic Mustang, a vintage F-100, or a dedicated race car, these components will not let you down.

For more details and to find the exact fuel pump your Ford 302 needs, visit KEMSO at https://www.kemsoracing.com/


Back to blog