Blowby filters in gas engines – function, benefits, and efficiency potential
Gas engines are designed for continuous operation, high efficiency, and low emissions. One of the lesser-known but critical components in this equation is the blowby filter. Often overlooked, this filter plays a central role in protecting engine components, improving combustion quality, and extending maintenance intervals.
In this article, we’ll explore what a blowby filter is, why it’s essential, and how the right solution can significantly boost performance and reduce operating costs.
What is a blowby filter?
During combustion, a small portion of gas escapes past the piston rings and enters the crankcase. This mixture – known as blowby gas – contains unburned fuel, exhaust gases, and fine oil droplets. Since it’s not expelled through the exhaust stroke, a crankcase ventilation system is required to manage the pressure buildup.
The blowby gas poses several challenges. If left untreated, it can carry oil mist and combustion residues into the intake system, leading to fouling of turbochargers, valves, pistons, and intercoolers. This contamination reduces performance, increases oil consumption, and accelerates wear.
A blowby filter separates the oil from the gas before reintroducing each into the engine: oil returns to the oil pan, and cleaned gas is routed to the intake manifold. In larger engines, solid filtration has become the preferred method due to its reliability and cost-efficiency.
Why blowby-filters are essential in gas engines
Modern gas engines run for thousands of hours under high thermal and mechanical loads. Any inefficiency in filtering blowby gas can quickly lead to issues such as:
- Increased oil consumption and loss
- Contamination of the intake air system
- Higher maintenance requirements
- Negative impact on emissions performance
Blowby filters minimize these risks by capturing oil mist and fine particles. This not only protects engine components but also supports environmental standards by preventing unburned hydrocarbons from escaping into the atmosphere. For operators, the benefits are clear: longer service intervals, lower total cost of ownership, and more stable engine performance.
Case Study: Major efficiency gains through blowby filter upgrade
Standard OEM blowby filters often rely on one or two filtration stages. Over time, the filter medium becomes saturated, leading to rising differential pressure and eventually requiring replacement – often after just a few thousand operating hours.
PowerUP took a different approach by developing a patented deep filtration technology. The system uses a multi-layered filter fabric with integrated drainage channels, delivering:
- A high separation rate of 99.98%
- Less than 1 mg/m³ of residual oil
- Stable pressure levels over tens of thousands of hours
Thanks to this innovative design, filter lifespan exceeds 40,000 operating hours. This translates into fewer maintenance stops, reduced downtime, and significant cost savings – especially in high-load engine environments.
One of PowerUP’s customers faced persistent issues with clogged OEM blowby filters, which caused maintenance delays and increased the risk of overpressure in the crankcase. Filters had to be replaced every 4,000–8,000 hours depending on the setup.
By switching to the PowerUP blowby filter solution, the customer achieved:
- Extended filter life beyond 40,000 hours
- Consistently low differential pressure
- More than 60% reduction in maintenance costs
Today, over 500 units and retrofit kits are in operation worldwide, delivering reliable performance across a wide range of applications and gas types.
Want the full breakdown of the implementation, technical performance, and results?
Increase engine uptime and reliability with PowerUP
PowerUP specializes in high-performance parts and retrofit solutions for gas engines. Our blowby filter upgrade kits are engineered for durability, compatibility, and real-world efficiency. With 12 variants tailored to the most common OEM systems, we provide 1:1 replacements as well as customized retrofit kits for older or inefficient systems.
No matter which gas engine brand you operate, PowerUP provides the expertise and high-quality components to maximize performance – reliably, efficiently, and with long-term sustainability in mind.
