10 Best Valve Cover Breathers Reviewed for 2025

When I started diving into engine building, I quickly realized that proper crankcase ventilation isn’t just a suggestion—it’s crucial for both longevity and engine performance. Whether you’re dealing with blow-by pressure in a classic muscle car or trying to keep your universal cold air intake system clean, finding the right accessory is key. We’ve tested and compared some of the market’s leading options to help you choose the best valve cover breathers for your specific setup, ensuring you get superior airflow and oil separation.

IMAGE	PRODUCT NAME	AMAZON LINK
	RYANSTAR RACING 23MM High Flow Vent Valve Cover Breather…	View on Amazon
	Allstar Performance ALL36202 1-1/2″ Valve Cover Breather	View on Amazon
	(2-Pack) Calvana Round Push-In Breather with 1” Tube for…	View on Amazon
	(2-Pack) Calvana 3/4″ Push-In Chrome Valve Cover Breather…	View on Amazon
	Oval Valve Cover PCV Combo Kit, Aluminum Air Breather…	View on Amazon
	Black Round Push In Style Valve Cover Breather with Vent…	View on Amazon
	MUGE RACING 23mm Car Air Filter Universal Cold Air Intake…	View on Amazon
	Moroso 68817 Valve Cover Breather, Push In Style, Non Hooded	View on Amazon
	Round Push in Breather with 1in Tube for 1/4in Hole…	View on Amazon
	MUGE RACING 2Pcs Air Filter Cold Air Intake Filter…	View on Amazon

RYANSTAR RACING 23MM High Flow Vent Valve Cover Breather Filter Universal Car Air Filter Cold Air Intake Filter Small Air Filter Breather Universal Air Vent Cover Black

If you need a straightforward, high-flow filter solution, the RYANSTAR RACING breather is a great choice. It’s designed specifically for those utilizing cold air intake systems and requires a 23mm connection point. This filter excels at keeping contaminants out while promoting excellent volumetric efficiency by reducing air intake resistance. Made from durable metal and rubber, it’s built to last and is surprisingly easy to maintain.

Key features that stand out:
– Wide Compatibility: Compatible with most universal cars with a 23mm air intake.
– Premium Materials: Crafted from metal, filter paper, and rubber materials for durability.
– High Performance: Designed to keep out dust, dirt, and mud from your engine bay.

• Pros: Easy, non-damaging installation; boosts airflow efficiency; high-quality, cleanable materials.
• Cons: Compatibility is limited strictly to 23mm intake ports.
• Best for: Universal applications seeking maximum filtration in a small package.

Expert Opinion: This is a solid clamp-on breather filter designed more for universal cold air intake filtering than traditional V8 crankcase ventilation, offering strong performance for its specific application.

Allstar Performance ALL36202 1-1/2″ Valve Cover Breather

Allstar Performance is a name synonymous with quality racing components, and the ALL36202 breather lives up to that reputation. This breather is a vehicle-specific, clamp-on option suitable for valve covers that already feature breather tubes. It’s built ruggedly and focuses on providing reliable, simple ventilation without unnecessary flair, making it popular among professional builders.

Key features that stand out:
– Clamp-On Design: Secure installation on existing breather tubes.
– V/C Breather W/O Shield: Simple, exposed design focusing purely on ventilation flow.
– Vehicle Specific: Optimized fit for certain high-performance vehicles.

• Pros: Durable construction; trusted brand in racing; straightforward fitment.
• Cons: No shield means it might be prone to slightly more oil mist exposure.
• Best for: Vehicle-specific race applications and muscle cars requiring robust ventilation.

Expert Opinion: While simple in appearance, the Allstar breather offers industrial-grade quality. If your setup already has the appropriate breather tube, this provides a highly reliable way to manage crankcase pressure.

(2-Pack) Calvana Round Push-In Breather with 1” Tube for 1-1/4″ Hole in Valve Cover, Includes Grommet, Compatible with Spectre 4276, Fits SBC, BBC, SBF, 327, 350, 302, 454, and 502

For classic engine enthusiasts working on popular platforms like the SBC or BBC, this Calvana 2-pack is an excellent value. Not only do you get two breathers, but they are constructed with an internal baffle to prevent oil splash—a common issue with high-performance push-in units. The beautiful triple chrome-plated finish also adds a sharp aesthetic to any engine bay.

Key features that stand out:
– Optimal Ventilation: Internal baffle effectively prevents oil splash.
– Universal Compatibility: Designed for all valve covers with 1-1/4 inch holes.
– Durable and Robust: High-quality steel with a triple chrome-plated finish.

• Pros: Excellent value as a 2-pack; integrated baffle protection; sleek chrome appearance; perfect fit for classic muscle engine families.
• Cons: Requires a dab of oil during installation for the guaranteed tightest fit.
• Best for: Muscle car owners (SBC/BBC) looking for aesthetic quality and great oil separation.

Expert Opinion: This Calvana kit provides everything needed for a clean installation on a standard 1-1/4″ hole. The inclusion of the grommet and the baffled design makes this one of the best valve cover breathers for engine dress-up and functionality.

(2-Pack) Calvana 3/4″ Push-In Chrome Valve Cover Breather with Grommet – Compatible with Spectre 4299, Steel Construction for Superior Ventilation, Prevents Oil Splash, Easy Installation

This second offering from Calvana is designed for smaller breather holes, accommodating sizes from 3/4 inch to 1-1/4 inch thanks to the versatile included grommet. Like its larger counterpart, it boasts a premium chrome finish and features an internal baffle for highly effective oil control. A significant advantage here is the inclusion of a replaceable foam insert, simplifying long-term maintenance.

Key features that stand out:
– Effective Ventilation: Internal baffle ensures smooth operation and prevents oil splash.
– Versatile Fit: Engineered to fit a range of breather holes (3/4 inch to 1-1/4 inch).
– Convenient Maintenance: Features a replaceable foam insert.

• Pros: Excellent versatility in sizing; easy maintenance due to the replaceable insert; secure installation with included grommet.
• Cons: The foam insert will require eventual replacement, unlike non-filtered units.
• Best for: Users needing a smaller diameter chrome breather with customizable fitment and simple filter maintenance.

Expert Opinion: The replaceable foam filter is a major plus for those who prefer to keep their filtration media fresh. This unit is reliable, attractive, and offers fantastic flexibility in fitting different valve cover holes, making it one of the most adaptable best valve cover breathers reviewed.

Oval Valve Cover PCV Combo Kit, Aluminum Air Breather Combo Valve Cover Suitable 1″ Pipe of 1-1/4″ Valve Cover Holes – Set of 2 (Black)

If you’re looking for a coordinated, stylish set that covers both the breather and PCV requirements, this aluminum combo kit is fantastic. The attractive finned design in black polished aluminum looks incredibly sharp. Crucially, these breathers feature two rubber sealing rings, which significantly improve the sealing performance compared to simple push-in breathers that rely only on the single grommet lip.

Key features that stand out:
– High Quality Material: Made of high-quality, durable, high-temperature resistant aluminum.
– Performance: Includes two rubber sealing rings for superior sealing performance.
– Finned Design: Aesthetic finned look in polished black.

• Pros: Attractive, modern design; exceptional sealing performance; dual-purpose kit (breather and PCV); long-lasting aluminum material.
• Cons: The oval shape might not visually appeal to all traditionalists.
• Best for: Modern engine builds or restorers prioritizing aesthetic quality and high-reliability sealing.

Expert Opinion: The robust aluminum construction means these units handle heat exceptionally well. The dual-seal feature is noteworthy, as it guarantees that crankcase pressure is vented appropriately without leakage.

Black Round Push In Style Valve Cover Breather with Vent Tube Compatible for 1-1/4″ Hole Valve Cover

This push-in breather is designed for engine setups that require controlled venting, often to the back of the carburetor or the air cleaner housing. The integrated 1/2″ tube allows the user to route blow-by gases away from the engine bay or back into the intake for emission control purposes. It uses the standard 1-1/4″ hole sizing, fitting many popular older V8 engines.

Key features that stand out:
– Integrated Vent Tube: Features a 1/2″ tube for routing ventilation gases.
– Tight Fitment: Designed to fit extremely snugly into valve covers to prevent rotation.
– Wide Application: Fits common engines like SBC, BBC, SBF, 327, 350, etc.

• Pros: Ideal for mandated emissions systems or controlled venting; classic push-in style; highly secure fit.
• Cons: Requires an extra hose connection and routing, adding complexity.
• Best for: Engines that need a closed system or controlled venting back into the intake.

Expert Opinion: If your engine requires a closed PCV system setup—meaning you cannot simply vent to atmosphere—this specific breather with a tube connector is essential for legal or optimal performance operation.

MUGE RACING 23mm Car Air Filter Universal Cold Air Intake Filter High Flow Vent Valve Cover Breather Filter (Red)

The MUGE RACING 23mm filter is functionally almost identical to the RYANSTAR unit, but offers a vibrant red color option for those looking for a flash of color in their engine bay. This universal filter is lightweight and durable, focusing on significantly reducing air intake resistance to boost volumetric efficiency when the engine is running. It’s an excellent choice for keeping high-flow intake systems clean.

Key features that stand out:
– Premium Material: Made of metal, filter paper, and rubber material, ensuring durability.
– High Flow Function: Increases intake airflow and filters impurities effectively.
– Aesthetic Choice: Bright red color option.

• Pros: Very lightweight; easy to clean and maintain; effective debris protection; bright color option.
• Cons: Only compatible with 23mm intake ports.
• Best for: Universal cold air intake systems where a touch of color is desired.

Expert Opinion: These small, high-flow filters are crucial if you have an open intake or are using the breather as an auxiliary filter. The performance is solid, and the red finish is deep and striking.

Moroso 68817 Valve Cover Breather, Push In Style, Non Hooded

Moroso is a well-respected brand in high-performance automotive parts, making the 68817 a reliable choice for serious builders. This is a straightforward, non-hooded, push-in style breather focused purely on maximizing ventilation volume and reliability. While the packaging details are light, Moroso products are generally known for vehicle-specific, quality fitments and material durability suitable for race conditions.

Key features that stand out:
– Trusted Brand: Manufactured by Moroso, known for racing components.
– Push In Style: Simple, secure fitment for appropriate valve covers.
– Non Hooded: Unrestricted design for maximum air exchange.

• Pros: Extreme durability; very simple design means fewer points of failure; guaranteed quality by Moroso.
• Cons: Lack of an internal shield or hood means oil mist control might be reduced.
• Best for: Engine builders who value brand reputation and maximum ventilation above filtration complexity.

Expert Opinion: For high-output motors where blow-by is intense, a high-volume breather like the Moroso is necessary. While it lacks some cosmetic features of other breathers, its functionality is unquestionable.

Round Push in Breather with 1in Tube for 1/4in Hole in Valve Cover, Round Valve Cover Breather, Round Push in Breather Valve Cover Breathers Replacement for SBC BBC SBF 327 350 302 454 502(Black)

Similar to Product #6, this black round push-in breather is designed for the widely used 1-1/4″ valve cover hole and features an integrated 1-inch tube for connection to a closed venting system. Constructed from durable steel, it is corrosion resistant and focuses on providing a long, secure operational lifespan. Note that while it requires a grommet for installation, the grommet is not included in this specific package.

Key features that stand out:
– Valve Cover Vent: Made of corrosion-resistant steel material.
– Tight Fit: Requires a little oil during installation to ensure it does not turn or loosen.
– Perfect Compatibility: Replacement for popular V8 engines (327, 350, 454, etc.).

• Pros: Durable steel construction; ideal for systems requiring a venting tube; highly secure fit once installed.
• Cons: Grommet must be purchased separately, adding an extra step to installation.
• Best for: Restorations where a separate grommet is already available or where color coordination dictates a black finish.

Expert Opinion: This is a solid, functional piece, but buyers must be aware of the need to source their own grommet. Its primary value is in providing a secure, tube-venting solution for classic muscle engines.

MUGE RACING 2Pcs Air Filter Cold Air Intake Filter Breather 12mm Valve Cover Breather Filter For Car and Motorcycle(Black)

If your application requires a much smaller connection point, the MUGE RACING 12mm filter is exactly what you need. This 2-pack is compatible with most universal cars and motorcycles using a 12mm air intake port. Like its 23mm counterpart, these small breathers are lightweight, durable, and excel at preventing dirt and mud from entering the engine. They are perfect for small auxiliary ventilation points.

Key features that stand out:
– Small Connection Size: Specifically designed for 12mm air intakes.
– Dual Pack: Great value for applications requiring two small filters (e.g., motorcycles or dual points).
– High Performance: Designed to filter dust and dirt effectively.

• Pros: Excellent value as a pair; ideal for smaller engines or motorcycles; high durability materials.
• Cons: Not suitable for larger, high-pressure V8 valve cover holes.
• Best for: Motorcycles, small engine projects, or universal auxiliary vents requiring a 12mm fit.

Expert Opinion: Finding quality filters in the 12mm size can be tough, so this MUGE 2-pack is a reliable find. They are among the best valve cover breathers for small-scale applications needing effective filtration.

Comparison Insights for Selecting the Best Valve Cover Breathers

Choosing among the best valve cover breathers often comes down to three key factors: application, material, and required hole size.

If you are restoring a classic V8 engine (SBC/BBC), look toward the Calvana and Black Round Push-In units. These focus on the standard 1-1/4″ hole size and offer the aesthetic appeal of chrome or black steel, plus critical features like internal baffling to minimize oil misting. If you need a fully closed system where gases must be routed back into the intake, the models with the integrated vent tube (Products #6 and #9) are essential.

For universal applications, particularly those involving cold air intakes or non-standard crankcase vents, the RYANSTAR and MUGE RACING filters dominate. They come in specific clamp-on sizes (12mm or 23mm) and prioritize high-flow filtration media. They are fantastic if you just need to keep small air ports clean and efficient.

Finally, appearance matters. The Oval Valve Cover PCV Combo Kit stands out for its modern, finned aluminum look and superior sealing rings. If aesthetics are paramount, aluminum often provides a cleaner, lighter look than traditional chrome steel.

Final Verdict

Selecting the right breather depends heavily on your engine’s specific needs—not just performance, but also aesthetics and legal compliance.

If you own a classic muscle car and want both function and show-car polish, the (2-Pack) Calvana Round Push-In Breather (Product #3) is our top recommendation. The included grommet, built-in baffle, and stunning chrome finish make it the best all-around traditional choice.

For specialized high-performance builds where maximum flow and brand trust are critical, the Moroso 68817 Valve Cover Breather provides unmatched reliability, even if it sacrifices some oil control features.

For universal applications or high-tech cold air systems, the RYANSTAR RACING 23MM High Flow Vent Valve Cover Breather offers the best balance of filtration quality, durability, and high flow for its specific size requirement.

Ultimately, whether you choose a simple push-in or a high-flow filter, prioritizing reliable sealing and appropriate ventilation size is what will ensure your engine stays healthy and performs optimally.

Frequently Asked Questions About Best Valve Cover Breathers

What exactly is the purpose of a valve cover breather?

A valve cover breather is an essential part of the crankcase ventilation system. Its primary job is to relieve pressure that builds up inside the engine crankcase, which is caused by “blow-by” (combustion gases leaking past the piston rings). If this pressure isn’t vented, it can lead to oil leaks, seal damage, and reduced engine power. The breather allows fresh air in or contaminated air out, balancing the internal pressure.

Do I need a breather if my engine already has a PCV valve?

Yes, usually you do. Most engines use a Positive Crankcase Ventilation (PCV) system. The PCV valve handles the active suction of crankcase gases back into the intake manifold, typically under vacuum. The breather often serves as the fresh air intake point into the crankcase, ensuring a full circulation loop. For high-performance engines, the breather also acts as a crucial secondary vent when excessive blow-by overwhelms the PCV system.

How often should I clean or replace my valve cover breather filter?

The frequency depends heavily on the type of breather and driving conditions. If you have a standard reusable foam or mesh filter, you should inspect it every few thousand miles or during every oil change. If it’s visibly dirty, soaked in oil, or clogged, it should be cleaned using appropriate solvents (like dish soap and water, or dedicated filter cleaner) and then re-oiled if necessary. Replace non-cleanable filters when they show signs of collapse or complete saturation.

What is the difference between a “push-in” and a “clamp-on” breather?

A push-in breather (like the Calvana units) has a neck that seals directly into a grommet inserted into the valve cover hole. This is common on older V8 engines. A clamp-on breather (like the RYANSTAR filters) is typically a small air filter that attaches via a hose clamp to a hose fitting or dedicated tube, often used in universal applications or on cold air intake systems.

Should I choose chrome steel or aluminum breathers for my engine?

This is primarily a matter of preference and budget. Chrome steel breathers are classic, highly durable, and often cheaper—they give a traditional muscle car aesthetic. Aluminum breathers (like the Oval PCV Combo) are lighter, resist corrosion better, and often handle extreme engine heat more effectively. They usually appeal to a more modern or high-end build look.

What is “oil splash” and how do internal baffles prevent it?

Oil splash, or oil misting, occurs when hot crankcase pressure forces fine droplets of oil through the breather and out onto the engine bay, creating a mess. Internal baffles are metal plates or chambers built into the breather housing. They force the vented air to take a winding path, causing the heavier oil droplets to condense and fall back into the valve cover before the air is expelled. This makes baffled breathers among the best valve cover breathers for keeping your engine bay clean.