Puke Can

A puke can is a slang term for a small container attached to a race car that catches fluids like coolant, oil, or transmission fluid that would otherwise spill onto the track or engine bay.

In motorsports, keeping the track clean and safe is critical. When engines get hot during racing, fluids can expand and overflow from their normal tanks. Without a catch system, these liquids would drip onto the track surface, creating dangerous slick spots that could cause other cars to lose control. A puke can solves this problem by giving these excess fluids a safe place to go.

The name "puke can" comes from the way fluids seem to "puke" or overflow from the engine when it gets hot. While it's a casual term you'll hear in the paddock or garage, these devices are more formally called catch cans or overflow tanks. Regardless of what you call them, they serve the same essential purpose of containing escaped fluids.

The most common type connects to the radiator's overflow system. When your engine heats up during a race, coolant expands and needs somewhere to go. Instead of venting onto the ground, it travels through a hose into the puke can. Once the engine cools down, some systems allow this coolant to be drawn back into the radiator, while others simply hold it for disposal later.

Oil catch cans are another popular variation, especially in high-performance racing engines. These connect to the engine's crankcase ventilation system, which normally recirculates gases back into the engine. The problem is these gases often contain oil mist and other contaminants. An oil catch can filters out this oily residue before it can coat your intake valves and pistons, which helps maintain engine performance and prevents carbon buildup.

Installing a catch can typically involves mounting a small cylindrical tank somewhere in the engine bay and connecting it with hoses to whichever system needs protection. Some designs are simple collection bottles that need periodic draining, while more sophisticated versions include filters, baffles to separate liquids from gases, and return lines that send clean fluids back where they belong.

In professional racing, puke cans aren't just good practice—they're often required by regulations. Race sanctioning bodies mandate them to protect both driver safety and track conditions. Even a small amount of fluid on a racing surface can cause a serious accident at high speeds.

For street cars modified for track use, catch cans serve double duty. They protect performance while also helping meet emissions regulations in some cases, though breather-style cans that vent to atmosphere may not be legal for street driving in all areas. Whether you're building a weekend track car or a full competition vehicle, understanding how catch cans work is fundamental to proper motorsport safety and vehicle preparation.