Diesel engines are renowned for their durability and torque, making them a favorite among performance enthusiasts. However, maintaining optimal performance and ensuring engine longevity require addressing specific challenges inherent to diesel powerplants. One effective solution is the installation of an  oil catch can, a device designed to capture oil vapors and other contaminants before they enter the engine's intake system.

Understanding Blow-By in Diesel Engines

All internal combustion engines experience "blow-by," a condition where combustion gases escape past the piston rings into the crankcase. In diesel engines, this phenomenon is more pronounced due to higher compression ratios. Blow-by gases carry oil vapors and other contaminants, which, if recirculated into the intake system, can lead to several issues:

• Carbon Buildup: Oil vapors can combine with soot from the Exhaust Gas Recirculation (EGR) system, leading to carbon deposits on intake valves and the manifold. Over time, this buildup restricts airflow, reducing engine efficiency and performance.
• Reduced Fuel Efficiency: Contaminants in the intake charge can disrupt optimal combustion, leading to increased fuel consumption. By ensuring cleaner air enters the combustion chamber, oil catch cans help maintain fuel efficiency.
• Increased Emissions: Oil vapors entering the combustion chamber can result in incomplete combustion, producing higher levels of harmful emissions. Capturing these vapors before they reach the intake helps in reducing the vehicle's environmental impact.
• Engine Longevity: Preventing oil and soot buildup in the intake system reduces wear on engine components, contributing to a longer engine lifespan. This is particularly important for diesel enthusiasts who often demand high performance from their vehicles.

The Role of Oil Catch Cans

An oil catch can, also known as an air-oil separator, is installed in the crankcase ventilation system to intercept oil vapors and other contaminants from blow-by gases. By capturing these substances before they re-enter the intake manifold, the catch can ensures that only clean air is recirculated, thereby maintaining engine cleanliness and performance.

The first of these systems in American diesel engines were found in the early Isuzu-built Chevy LUV trucks of the early 1980s and were incorporated simply to prevent oil drops from the road draft tube of that generation of engine. (Hard to believe, since draft tubes had disappeared from American gasoline engines more than two decades before!) GM continued to develop and refine this system for their light duty 6.5 liter Detroit (and later Navistar-built) engines which found their way into the squarebody trucks, the GMT-400 platform, and even the HMMWV used in the armed forces.

Catch cans have become far more important, though, with the advent of turbocharging as the standard for diesel engines since then, so it’s ironic they aren’t usually found on modern diesels as factory equipment. Why there are a lot of theories as to why that is, some better than others, the primary reason seems to be it’s another maintenance step owners would forget to take, so manufacturers have eliminated them.

The truth is, oil catch cans are a critical safety concern for diesel engines with the risk of engine runaway, a condition where the engine uncontrollably accelerates due to the combustion of unintended fuel sources, such as oil vapors. Excessive oily blow-by can introduce sufficient oil into the intake system, providing an alternative fuel source that leads to runaway scenarios. The problem is, once ignited, the turbo can draw not only oil vapors, but oil from the actual crankcase as fuel. By installing an oil catch can, these oil vapors are captured before they can accumulate in the intake, significantly reducing the risk of engine runaway.

Now, runaways aren’t common, but as one staff member can attest, they can absolutely get your attention. Aside from a layer of protection against a runaway engine, though, an oil catch can setup has quite few other benefits…

• Enhanced Engine Performance: By preventing oil and carbon buildup in the intake system, the engine maintains optimal airflow and combustion efficiency, resulting in improved power output. Unlike gasoline engines, diesel fuel doesn’t have the solvent qualities of gasoline, so taking steps to minimize crankcase oil into the combustion chambers of your diesel engine will keep things cleaner over thousands of miles.
• Improved Fuel Economy: A cleaner intake system ensures more efficient combustion, which can lead to better fuel mileage.
• Reduced Maintenance Costs: Keeping the intake manifold and valves free from deposits decreases the likelihood of engine issues, reducing the need for costly repairs.
• Extended Turbocharger Life: By ensuring that only clean air reaches the turbocharger, the device experiences less contamination and wear, prolonging its operational lifespan.

Selecting the Right Oil Catch Can

When choosing an oil catch can for your diesel engine, consider the following factors:

• Compatibility: Ensure the catch can is designed for diesel applications and is compatible with your specific engine model.
• Quality Construction: Opt for catch cans made from durable materials, such as aluminum or high-quality plastics, to withstand the harsh engine environment
• Effective Filtration: Look for designs that offer multi-stage filtration to efficiently separate oil vapors from the blow-by gases.
• Ease of Maintenance: Choose a catch can with accessible draining and cleaning features to facilitate regular maintenance.

Proper installation of the oil catch can is crucial for optimal performance, follow manufacturer guidelines closely, but remember to periodically check and empty the catch can to prevent overflow and ensure your catch can is doing its job.

Incorporating an oil catch can into your diesel engine's system is a proactive measure that offers numerous benefits, from enhancing performance and fuel efficiency to helping your turbocharger to last far longer. For diesel enthusiasts seeking to maximize their vehicle's potential, investing in a high-quality oil catch can is a wise decision that contributes to the engine's longevity and reliability.

At Alligator Performance, we offer a selection of premium oil catch cans suitable for various diesel applications. Explore our range to find the perfect fit for your vehicle and take a significant step toward maintaining your engine's health and performance.