Replacing Foam In Your Fuel Cell: A Step-By-Step Guide

Foam baffling in a fuel cell is an essential safety feature that prevents fuel sloshing and reduces the risk of explosion. It is also important for performance, as it prevents fuel sloshing inside the bladder, allowing for more constant fuel delivery. To replace the foam, you will need to remove the old foam and install new foam. This can be done by squeezing the new foam blocks through the fill plate hole and stacking them inside the cell. It is important to use the correct type of foam for your specific fuel cell and fuel type to ensure safety and performance.

Removing the old foam from the fuel cell

Removing the old foam from a fuel cell can be a challenging task, as demonstrated by a user on Yellow Bullet Forums. In their case, the process resulted in a hospital stay. However, with care and the right tools, it can be accomplished successfully. Here are some detailed instructions to guide you through the process:

Before beginning, make sure you have the necessary safety equipment, such as gloves and eye protection, to avoid any injuries. It is also recommended to work in a well-ventilated area to prevent inhaling fumes.

Start by removing the trim ring from the fuel cell opening. This will provide you with better access to the foam inside. Depending on your fuel cell, you may need to use a wrench to hold the fasteners while removing the trim ring. Be cautious when handling the trim ring, as the edges may be sharp and can cause cuts.

Next, you will need to carefully reach into the fuel cell and grab a piece of the foam. If your hand does not fit through the opening, consider using a tool such as a metal coat hanger with a hook on the end to grab the foam and pull it out. Alternatively, an electric carving knife can be useful for cutting the foam into smaller, more manageable pieces that can then be flushed out.

When removing the foam, be cautious not to damage the bladder of the fuel cell. Avoid using sharp tools that could puncture the bladder. It is important to note that some fuel cells have a simple can and lid design, allowing easy access to the interior.

Once you have removed all the old foam, take the time to inspect the bladder for any signs of damage or deterioration. This is an important step to ensure the continued safe operation of your fuel cell.

Finally, dispose of the old foam properly, following any local regulations or guidelines for hazardous waste disposal.

Remember to work carefully and patiently throughout the process, and if you are unsure or uncomfortable with any steps, it may be best to consult a professional or seek advice from a reputable forum or mechanic.

Choosing the right type of foam for your fuel cell

When choosing the right type of foam for your fuel cell, there are several factors to consider. Firstly, it is essential to understand the purpose of foam baffling in a fuel cell. The primary functions of foam in a fuel cell are to reduce fuel sloshing and prevent explosions by minimising the concentration of fuel vapour and air. Therefore, the type of foam selected should effectively serve these purposes.

Secondly, consider the type of fuel used. Different types of fuel can have varying effects on the foam. For example, foam used with gasoline can last about five years, whereas with E85 or other alcohol-based fuels, the lifespan of the foam may be shorter. Additionally, the compatibility of the foam with the fuel type is crucial. Some foams are designed for use with hydrocarbon fuels only and are not suitable for fuels containing alcohol, methanol, or similar additives.

Thirdly, the colour of the foam can be an indicator of its intended application and desired density. Blue, black, red, and yellow foams are commonly used in racing applications, with yellow foam often being the longest-lasting and having high chemical resistance to modern fuels. It is also essential to consider the size and shape of the foam blocks to ensure they fit properly within the fuel cell. Standard sizes include 6", 8", and 12" blocks, which can be cut to size if needed.

Finally, the quality of the foam is an important consideration. Cheap foam may disintegrate faster and clog fuel filters, leading to potential issues and increased maintenance. Opting for higher-quality foam from reputable manufacturers can help ensure the longevity of the foam and reduce the risk of fuel system problems.

Cutting the foam to fit the fuel cell

Firstly, it's important to understand the purpose of the foam. Fuel cell foam serves two main purposes: reducing fuel slosh and preventing electrostatic build-up. The former ensures constant fuel delivery, while the latter mitigates the risk of an explosion. With this in mind, it's clear why properly fitting foam is essential.

When cutting the foam, you'll want to ensure it fits snugly inside your fuel cell. The foam should be cut to match the shape and size of the cell, leaving no gaps for movement. This precision will help maximise the foam's effectiveness in reducing fuel slosh. To achieve this, carefully measure the dimensions of your fuel cell and transfer those measurements to the foam before cutting.

The foam typically comes in rectangular bricks or blocks, which you'll need to squeeze through the fill plate hole of the fuel cell. You may need to cut the foam into smaller pieces to fit through the hole. Stack the pieces inside the cell until it's completely full. This process may vary depending on the type of fuel cell you have, so it's important to refer to the manufacturer's instructions or seek advice from fuel cell experts.

It's worth noting that different types of foam are available for different applications and desired densities. For racing applications, you'll commonly find Blue, Black, Red, or Yellow foams. Yellow foam, for example, is known for its longevity and high chemical resistance to modern fuels, making it compatible with racing fuel, standard pump fuel, and diesel. However, it is not suitable for use with alcohol, methanol, or similar additives. Always choose a foam that is compatible with your intended fuel type.

Finally, when handling the foam, be cautious not to rip or damage it. Fuel cell manufacturers typically cut the foam in a way that cauterizes the edges to prevent disintegration. Any damage to the foam could introduce contaminants into the fuel cell and impact its performance.

Inserting the foam into the fuel cell

Before inserting the foam, it is crucial to choose the right type of foam for your fuel cell. Foam can come in several varieties, and the appropriate type depends on the specific application and desired density. For racing applications, commonly used foam colours include Blue, Black, Red, or Yellow. It is important to select a foam that is compatible with the type of fuel you will be using, as some foams are designed specifically for certain types of fuel, such as gasoline, ethanol, or diesel. Ensure that the foam you choose has a high chemical resistance to modern fuels and is suitable for the fuel type you will be using.

Once you have selected the appropriate foam for your fuel cell, you can begin the insertion process. The foam typically comes in rectangular bricks or blocks that need to be inserted through the fill plate hole of the fuel cell. Carefully squeeze the foam blocks through the hole and stack them up inside the cell until it is completely full. It is important to ensure that the foam fits snugly and securely inside the cell to maximise its effectiveness in reducing fuel slosh and preventing explosions.

When handling the foam, it is important to be gentle and avoid ripping or damaging it. Fuel cell manufacturers put a lot of care into cutting the foam to ensure that the edges are cauterized to prevent the foam from falling apart. Ripping the foam can compromise its integrity and reduce its effectiveness. Additionally, be cautious not to leave any gaps or spaces between the foam blocks as this can defeat the purpose of installing the foam in the first place.

After you have inserted all the foam blocks and ensured they are securely in place, you can reassemble the fuel cell by bolting the lid back on. It is important to follow the manufacturer's instructions for reassembling the fuel cell correctly and safely. Once the fuel cell is reassembled, you can test it to ensure it functions properly and that the foam is doing its job of reducing fuel slosh and suppressing explosions.

Remember to inspect and maintain your fuel cell foam regularly. Over time, the foam may deteriorate or become contaminated, affecting its performance. Always refer to the maintenance schedule provided by the manufacturer and carefully inspect the foam for any signs of damage or deterioration. By taking proper care of your fuel cell foam, you can ensure optimal performance and safety for your vehicle.

Maintaining and inspecting the foam

Maintenance Schedule:

Freddie Turza, of VP Racing Fuels, emphasises the importance of regular maintenance of your fuel cell foam. It is recommended to follow a maintenance schedule and inspect the foam at regular intervals to ensure its effectiveness and integrity.

Removal and Inspection:

When inspecting the foam, carefully remove it from the bladder and place it on a clean surface. Be cautious not to rip the foam, as manufacturers like Superior Fuel Cells design the foam in a way that cauterises the edges to prevent disintegration. Inspect the foam for any signs of deterioration or damage.

Checking for Contaminants:

It is crucial to check your fuel filter regularly, as suggested by Paul Culp of Superior Fuel Cells, who inspects his filter every three races. Look for any particles that could originate from dirt or contaminated fuel. Additionally, Culp advises against a common practice among racers: poking a stick into the fuel cell to measure fuel levels. This can not only damage the foam but also introduce contaminants into the cell.

Fuel Compatibility:

When purchasing a fuel cell, Dave Dack of Aero Tec Laboratories (ATL) recommends consulting with experts to ensure the fuel cell and foam are compatible with the type of fuel you will be using. Different foams are designed for specific fuels, such as ATL's yellow SF-103 for gasoline with up to 85% ethanol and charcoal gray SF-110 for 100% alcohol. Using the wrong type of foam with your fuel can lead to premature aging and deterioration.

Fuel System and Fuel Changes:

While the foam in your fuel cell may withstand corrosive, alcohol-based fuels, other components of your fuel system might not. Ethanol-style fuels, for instance, can be corrosive and attack certain parts of the fuel system. Additionally, switching between different types of fuel with the same cell can, in some cases, cause a chemical reaction that accelerates the deterioration of the fuel system. It is advisable to use a separate fuel cell for each type of fuel you intend to use.

Foam Selection:

When selecting foam for your fuel cell, consider the application and desired density. Foam is typically identified by its colour, with common options being Blue, Black, Red, or Yellow. Yellow foam, for example, tends to be long-lasting and has high chemical resistance to modern fuels, making it compatible with racing fuel, standard pump fuel, and diesel. However, it is important to note that foam designed for hydrocarbon fuels should not be used with alcohol, methanol, or similar additives.

By following these guidelines and regularly maintaining and inspecting your fuel cell foam, you can help ensure optimal performance, safety, and longevity of your fuel system.

Frequently asked questions