Why Nashville Performance Builds Deserve a DIY Catch Can System

For gearheads building performance cars in the Nashville area—whether it’s a weekend track car, a street-legal sleeper, or a turbocharged commuter—keeping the engine bay clean is as important as the horsepower numbers. One often overlooked upgrade is a quality crankcase ventilation system. An oil catch can is a cheap, effective way to prevent oil vapor and blow-by gases from recirculating through the intake, which can lead to carbon buildup on valves, intercooler contamination, and reduced octane. In Music City’s humid summers and stop-and-go traffic, a properly set-up catch can also helps keep the PCV system working efficiently, extending the life of expensive forced-induction parts.

Building a budget-friendly catch can system doesn’t require a full machine shop or a hundred-dollar billet reservoir. With a few hours of shop time, some basic hand tools, and parts sourced from salvage yards or online marketplaces, you can assemble a functional system that rivals expensive commercial kits. Below we walk through the entire process—from understanding the physics of crankcase ventilation to installing and maintaining your own custom setup.

How a Catch Can System Works in a Performance Engine

Every internal combustion engine produces blow-by—gases that sneak past the piston rings during compression and combustion. These gases contain unburned fuel, water vapor, and atomized oil. In modern engines, the PCV (positive crankcase ventilation) system routes this mixture back into the intake manifold to be reburned. That’s fine for emissions and mild driving, but under high load—exactly where Nashville performance builds live—blow-by volume increases dramatically, and the intake begins to suck in oil droplets that coat the intake tract and eventually bake onto the back of intake valves.

A catch can sits in-line between the valve cover breather outlet and the intake manifold. The can itself is a baffled container that forces the blow-by gases to slow down and cool, causing oil and heavier particulates to condense and collect in the bottom. The cleaned air then continues into the intake. For naturally aspirated builds, the benefit is slower carbon buildup and healthier valve stem seals. For forced induction setups—common in Nashville’s street racing scene—a catch can prevents oil from reducing intercooler efficiency and causing detonation.

Budget systems typically use an open-vent configuration (venting to atmosphere with a small filter) or a closed-loop system that returns cleaner air to the intake. The choice depends on your local emissions laws and how much you want to simplify the installation. For most performance builders on a tight budget, an open-vent system with a breather filter is the easiest and cheapest route.

Materials and Parts: What You Actually Need

Skip the overpriced brand-name catch cans. A budget build can use repurposed hardware store components or used parts from other vehicles. Here’s the full shopping list for a Nashville-ready system that won’t empty your wallet:

  • Catch can body: Look for an empty aerosol can (e.g., a used brake cleaner can, thoroughly cleaned), a small aluminum motorcycle oil cooler, or a salvaged plastic separator from a late-model GM or Ford. Even a 5-inch length of PVC pipe with threaded caps works if you drill baffle holes inside.
  • Hose: Silicone heater hose or vacuum hose, 3/8″ or 5/8″ ID depending on your engine’s stock PCV hose diameter. About 4 feet total.
  • Barbed fittings: Two barbed brass or aluminum fittings to screw into the catch can body (or use push-to-connect fittings if you prefer). Sizes: one for inlet, one for outlet.
  • Hose clamps: Worm-gear clamps or spring clamps—at least 4.
  • Breather filter: A small K&N-style pod filter that fits over the can’s vent (for open setups) or a second hose barb for closed-loop.
  • Mounting hardware: A small metal bracket (scrap metal, aluminium or steel), bolts, nuts, and rubber grommets to isolate vibration.
  • Tools: Drill with metal bits, screwdrivers, adjustable wrench, hacksaw, file, and a dremel for smoothing edges.

Total cost can be under $30 if you already have some tools. Even if you buy everything new from an auto parts store or Amazon, you’re looking at under $60—far less than the $150–300 charged by fancy billet catch can kits.

Where to Find Cheap Catch Can Cores

Nashville has a thriving used-parts ecosystem. Check local pull-a-part yards like U-Pull-It in Nashville for discarded SUV or truck engines—many have plastic oil separators already built into the valve cover. You can also look in the compressor section of old refrigerators for small metal canisters. Online marketplaces like Facebook Marketplace often list “project car parts” bags that include random vacuum fittings for cheap. Avoid using old brake fluid containers unless you’re sure they’re completely sterile—residual chemicals can degrade hoses.

Step-by-Step Assembly for a Budget Catch Can System

Every engine layout is different, but the general procedure is the same. We’ll use a typical 4-cylinder or small-block V8 as an example. Adjust hose routing based on your specific engine bay layout.

Step 1 – Identify PCV Ports and Plan Routing

Locate the crankcase vent outlet—usually a hose coming from the valve cover (or cam cover) to the intake manifold. There may be a second port on the passenger side valve cover. On many engines, the PCV valve itself is a good tie-in point. For naturally aspirated builds, you’ll install the catch can between the valve cover outlet and the intake. For turbo or supercharged setups, you may need two cans (one for each bank) or a single larger can if you merge the vent lines. Engine Builder Magazine has a thorough overview of PCV routing.

Step 2 – Prepare the Catch Can Body

If using a salvaged can or pipe, drill two holes on opposite sides: one for the inlet near the top, one for the outlet near the top on the opposite side. If you want maximum oil separation, drill a series of smaller holes inside the can to act as baffles. A coffee can with the bottom removed and a steel wool filter inside works too—just make sure nothing can shed particles into the engine. Thread the barbed fittings into the holes using Teflon tape to seal. For a breather-style system, drill a third hole for the breather filter on the top or side and install a grommet.

Step 3 – Mount the Catch Can

Find a location near the engine’s intake side where the can won’t hit hood hinges or heat sources like exhaust manifolds. Use the scrap bracket to create a simple L-bracket, drill mounting holes, and bolt the can securely. Rubber grommets between bracket and body minimize vibration, which helps prevent oil sloshing out of the breather filter if you have an open vent.

Step 4 – Connect Hoses

Cut the silicone hose into two pieces: one from valve cover vent to catch can inlet, one from catch can outlet to intake manifold or PCV valve location. If your engine has a dedicated PCV valve, you can plumb the can’s outlet after the PCV valve (on the intake side). Use hose clamps on all connections. For a closed-loop system, the outlet hose goes directly to the intake nipple. For an open system, cap the intake-side nipple with a vacuum cap and fit the breather filter onto the catch can’s top vent. Double-check that the hoses are not kinked and are at least 3 inches away from belts.

Step 5 – Final Checks

Start the engine and let it idle. Listen for vacuum leaks (hissing). Verify that the catch can is not under mechanical stress. Rev the engine a few times to ensure the PCV system is pulling; you should see the can’s walls cool slightly as air moves through. If you have an open filter, there may be a faint oil smell—normal for budget setups. After a short test drive, check for drips and retighten clamps.

Maintenance and Servicing Your Catch Can System

Even the most budget-friendly catch can needs periodic attention. In Nashville’s humidity, water condensation mixes with oil to form a sludge that can overflow if ignored. Check the can every two oil changes or every 3,000 miles—whichever comes first. Remove the can, pour the collected fluid into a catch bottle (do not dump down the drain; oil is hazardous), and wipe out any residual sludge with a rag. If you used steel wool or mesh baffles, inspect them for corrosion and replace if needed.

Hoses can harden over time due to heat cycles. Inspect the silicone for cracks every oil change, especially near the clamps. If you notice the engine idling rough or a check engine light related to EVAP system faults (P0455, P0442), check for a leak between the catch can and intake—a common issue in homemade systems.

Common Pitfalls and Troubleshooting

  • Oil smell inside cabin: Usually caused by an open catch can vent positioned near the cabin air intake. Relocate the breather to the opposite side or install a longer hose to route fumes toward the exhaust.
  • Excessive oil consumption after installation: The catch can itself doesn’t cause consumption; it collects what was already going into the intake. If your engine suddenly uses more oil, the issue is elsewhere (rings, turbo seals).
  • Vacuum leaks from plastic fittings: Budget fittings often have poor threads. Use thread-locking paste or PTFE tape rated for fuel/oil.
  • Clogging from thick sludge: In cold starts or high ethanol fuel blends, sludge forms faster. Warm up the engine before hard pulls to help the catch can work better.
  • Baffle breaks loose: If you used metal parts inside the can, secure them with a small hose clamp to prevent them from rattling loose and being sucked into the intake.

Performance Gains and Real-World Results

A catch can system won’t add peak horsepower on a dyno, but it preserves the power you already have. By reducing carbon buildup, you maintain consistent air/fuel ratios and ignition timing. Many Nashville street racers report smoother idle and better throttle response after installing a budget catch can on turbo setups. Over 20,000 miles, the difference in intake valve cleanliness is dramatic—compare photos from forums like Corvette Forum’s budget can thread. Additionally, your intercooler and charge pipes stay cleaner, which directly translates to better intercooler efficiency on hot Nashville afternoons.

For engine longevity, the catch can reduces the risk of oil fouling oxygen sensors and spark plugs—reducing maintenance intervals. Even if you’re building a simple daily driver, the protection is worth the minimal cost.

Advanced Options for the Budget Builder

If you want to improve separation efficiency without spending more, consider adding a condenser leg: run the inlet hose into a metal coil submerged in a small plastic box packed with aluminum foil (a “cold trap”). This condenses additional oil vapor, especially in winter. Or connect two cheap catch cans in series for increased volume. Some builders install a drain valve at the bottom of the can (like a brass radiator drain) so you can empty the can without removing it. Speedway Motors’ DIY guide has additional ideas on baffle designs using simple hardware.

Final Thoughts: Keep Your Nashville Build Clean on a Budget

Building a budget-friendly catch can system is a weekend project that pays dividends in engine cleanliness and reliability. Whether you’re tuning a K-swap for a parking lot meet or adding forced induction to a classic Mustang, the same principles apply—remove oil from the intake air before it can do damage. With salvaged parts, basic tools, and a little ingenuity, you can have a professional-grade system for less than what a single tank of race gas costs. And in Nashville’s performance scene, where every build is a statement, keeping your intake tract spotless is a mark of a builder who knows the details matter.

Ready to build your own? Start by visiting local salvage yards or scrounging through toolboxes—the next great catch can might already be sitting in your garage.