The Accusump is a specialized oil accumulator designed to enhance engine lubrication by maintaining oil pressure during critical moments, such as engine startup and sudden pressure drops. This device is particularly valuable in high-performance and racing applications, where oil delivery must remain consistent even under extreme conditions. Proper installation and operation are essential to ensure the Accusump functions as intended. This article provides a detailed guide on the installation, operation, and troubleshooting of Accusump oil accumulators, based on information from official manuals, technical documents, and installation tips.
Understanding the Accusump
The Accusump is a cylindrical oil accumulator that functions as a reservoir for pressurized oil. It is connected to the pressure side of an engine's oiling system and is charged by the engine’s oil pump. Its design includes a hydraulic piston that separates the oil reservoir from an air-charged side. The oil side features an outlet plumbed into the engine’s oiling system, controlled by a valve. The air side includes a pressure gauge (on non-turbo models) and a Schrader valve for pre-charging air pressure.
The primary purposes of the Accusump are pre-oiling—supplying oil pressure to the engine before startup—and surge control—supplying oil during momentary interruptions in the oil supply. This functionality is critical in racing environments where oil pressure can fluctuate due to high speeds, cornering, or other factors that may expose the oil pickup and disrupt oil flow.
The Accusump was originally developed to prevent oil pressure loss in racing applications. As cornering speeds increased and ground clearance decreased, shallow wet sump oil systems struggled to provide continuous oil pressure. The introduction of the oil accumulator solved this by providing the necessary oil during high-load periods when the oil pickup might become uncovered.
Accusump Models and Specifications
The Accusump is available in several models, each with varying capacities and dimensions to suit different engine configurations and applications. According to the installation manual, the following models are available:
- #24-006: 3 quart, 4 1/4" diameter by 16" long
- #24-016: 3 quart, 4 1/4" diameter by 22" long (high pressure)
- #24-026: 2 quart, 4 1/4" diameter by 12" long
- #24-046: 1 quart, 3 1/4" diameter by 12" long
- #24-126: 2 quart, 4 1/4" diameter by 12" long (Marine)
- #24-146: 1 quart, 3 1/4" diameter by 12" long (Marine)
Each model is designed to fit different engine setups and oil requirements. For example, the high-pressure variant (#24-016) is intended for applications where oil pressure is particularly critical, while the marine models are adapted for use in boats, where space and environmental conditions differ from standard automotive applications.
Installation Guidelines
Proper installation is crucial for the Accusump to function effectively. The installation process involves connecting the device to the engine’s oiling system and ensuring that it is correctly charged with air pressure. The following are key considerations during installation:
Mounting Location
The mounting location of the Accusump is critical for both structural integrity and performance. Clamps should be mounted on the very ends of the Accusump, as end caps are screw-in designs that benefit from additional structural support provided by the clamps. If clamps are mounted elsewhere on the unit, the clamping force can distort the tube and limit piston movement, which could impair the device's ability to store and release oil under pressure.
Connection to the Oil System
The Accusump connects to the pressure side of the engine’s oiling system. The exact point of connection depends on the specific application. For example:
Applications with remote oil filters or coolers: In systems with external oil coolers or remote filters, the Accusump should be connected on the oil return side of the system, close to the engine and after the oil has passed through the filter and/or cooler. A “T” fitting adapter is often used inline to connect the Accusump into an external oil line. In some cases, remote filter mounts with spin-on cartridges may have an extra port into which the Accusump can be directly connected.
Applications with spin-on filters: For engines using spin-on filters, the Accusump can be connected directly to the engine block or via an adapter. In either case, the connection should be secure and allow for proper oil flow without restriction.
Air Charging
After installation, the Accusump must be charged with air pressure using the Schrader valve. The pre-charge pressure should be set according to the manufacturer’s instructions and the specific application. A typical setup involves setting the pre-charge to a pressure slightly below the engine’s normal operating pressure to ensure the piston moves correctly during oil pressure fluctuations.
Operation and Testing
Once installed and charged, the Accusump should be tested to verify its functionality. The following steps can be used to test the device:
Pre-oiling Test: With the engine off, open the valve on the Accusump and observe the pressure gauge. The pressure should drop to the pre-charge level, and oil should be visible in the engine’s oil system. This confirms that the device is capable of releasing stored oil when needed.
Engine Shutdown Test: After the engine has been running and oil pressure is stable, close the valve on the Accusump and shut off the engine. The pressure gauge should display a value close to the engine’s oil pressure at the time of shutdown. If the pressure drops significantly or not at all, the device may not be filling properly.
Refill Test: Start the engine, allow oil pressure to build, and then open the valve. Oil should enter the Accusump, and the air pressure should increase to match the engine’s oil pressure. This process may take some time, depending on the size of the unit and the valve used.
If any of these tests fail, the Accusump may need to be adjusted or reinstalled. Common issues include incorrect pre-charge settings, improper valve operation, or blockages in the oil lines.
Troubleshooting Common Issues
Despite careful installation, issues can arise with the Accusump. The following are some common problems and their potential solutions:
Accusump Not Filling or Filling Too Slowly: This may be caused by a low pre-charge pressure, a blocked oil line, or an improperly positioned valve. Check the pre-charge setting and ensure the oil lines are clear. If the valve is electric, verify that it is functioning correctly.
Oil Level Exceeds Normal Capacity: If the Accusump is overfilled, it could indicate that the valve was left open after the engine was shut down. In manual systems, the valve must be closed before shutdown to prevent excess oil from entering the engine.
Pressure Gauge Malfunction: If the pressure gauge does not reflect the expected readings, the gauge may be faulty or improperly calibrated. Replace or recalibrate the gauge as needed.
Oil Leaks or Distorted Clamps: Improper clamping can lead to leaks or structural issues. Ensure that clamps are correctly mounted on the ends of the unit and that the fittings are secure.
Manual vs. Electric Valve Systems
The Accusump is available with either a manual or electric valve system, depending on the application:
Manual Valve: The manual valve requires the user to manually open and close the valve to control oil flow. This system is simpler and less expensive but requires more attention from the operator. Users must remember to close the valve before shutting down the engine to prevent overfilling.
Electric Valve: The electric valve is automatically controlled by the engine’s ignition system. When the ignition is activated, the valve opens to allow oil to flow into the engine. When the engine is turned off, the valve closes to store pressurized oil. This system is more convenient and reduces the risk of operator error.
Both systems have their advantages. The manual system offers greater control over when the valve is opened and closed, allowing for pre-oiling before startup. However, it requires more vigilance to ensure the valve is closed before shutdown. The electric system is more hands-off and suitable for applications where consistent operation is essential.
Safety and Maintenance Considerations
Proper maintenance is essential to ensure the Accusump continues to function correctly over time. The following are key safety and maintenance considerations:
Avoid Disassembly: Improper disassembly can cause damage to the Accusump and may be dangerous. If disassembly is necessary, it should be performed by a qualified technician.
Regular Inspection: Periodically inspect the oil lines, fittings, and pressure gauge for signs of wear, leaks, or damage. Replace any damaged components immediately.
Air Pressure Checks: The pre-charge pressure should be checked regularly to ensure it remains within the recommended range. If the pressure drops, the Schrader valve should be used to add air as needed.
Oil Level Monitoring: Monitor the engine’s oil level, particularly after using the Accusump. Since the device stores a significant amount of oil, the total oil capacity of the system may increase. Adjust the oil level accordingly to prevent overfilling.
Environmental Conditions: In marine or high-humidity environments, ensure that the Accusump is protected from moisture and corrosion. Use appropriate seals and coatings to prevent damage from exposure to the elements.
Conclusion
The Accusump oil accumulator is a valuable tool for maintaining consistent oil pressure in high-performance and racing engines. Its ability to store pressurized oil and release it during pressure drops makes it an essential component in applications where oil delivery must remain reliable under extreme conditions. Proper installation, operation, and maintenance are critical to ensuring the device functions as intended. Whether using a manual or electric valve system, users should follow the manufacturer’s guidelines to maximize the effectiveness and longevity of the Accusump.
By understanding the installation requirements, testing procedures, and common issues associated with the device, users can confidently integrate the Accusump into their engine systems. Regular maintenance and attention to detail will help ensure that the Accusump continues to provide reliable performance over time.