Catch Cans

Thanks for seeking us out, we appreciate you stopping by. The oil catch cans found on our site are the most efficient systems on the market today, available for all performance cars and light trucks. They are truly oil separating catch can systems second to none. So what makes a Catch Can efficient and effective at removing foul vapors from your engine? Give us a few minutes of your time and we’ll explain.

As you probably already know, the purpose of an oil separating system is to remove foul vapors produced by blow by during the combustion process. You want to remove this foul vapor containing unburned fuel, oil water, sulfuric acid, carbon monoxide, nitrous oxides and bunch of other nasty compounds. If you don’t, engine heat will bake it onto your valves and your valves. Here’s an example…
Clean and Dirty ValvesThis is referred to as valve coking and it is a huge problem for direct injection engines. Around 2008 the federal government mandated that all automotive manufacturers utilize direct injection in their engines by 2015. The reason being is that direct injection (DI) produces more horsepower, torque & increased fuel economy in a smaller displacement engine. The valve coking occurs because with DI the fuel is sprayed directly into the combustion chamber and no longer washes the valves. Here’s another example…

Direct Injection ex A
Direct Injection ex B
Direct Injection ex C
Direct Injection ex D
Direct Injection ex E
So, DI good… valve coking bad! Here’s where a Catch Can comes into play. In order to relieve crankcase pressure that develops from the accumulation of blow by gases the modern engine in your vehicle has what is called a PCV valve. The term PCV is an acronym for Positive Crankcase Ventilation. What the manufacturers have been doing for years is connecting the PCV valve to the intake manifold and utilizing the vacuum present there to open the valve and relieve the pressure. Along with the pressure comes the harmful blow by gases which is the reason why there is a catalytic converter on your exhaust system. Here’s but another example for your viewing pleasure…

Catalytic converter

The drawback with this design is that while the pressure is relieved and some of the gases are dealt with in the catalytic converter, some vapor is baked onto the valves. In about 4,000 miles the average DI engine looks like the valve on the left in the first image above. Before direct injection you could use fuel additives or some sort of cleaning system that you put in the intake to clean them. Now there really isn’t anything you can do but a manual cleaning with brushes or a media blast. We have done manual valve cleanings on a variety of vehicles. A walnut shell media blast was our method of choice. It’s time consuming but anyone can do it in four or five hours and a six pack of your favorite frosty beverage. You can pay to have it done as well but it will run you anywhere between $600 to $1,200 on average. We recommend finding a small German automotive repair shop that works on Audi, BMW, Mercedes or Volkswagen. The German auto repair shops and dealerships have been doing manual valve cleanings by this method for years. They realize the benefit of removing the intake manifold and going valve port by valve port to do the job right. Again you can do it yourself with a shop vac, media blasting equipment and a compressor all found at your local Harbor Freight or similar store for about $150.

Well enough about that, back to the catch can and how efficiently it works in comparison to the multitude of products on the market today. A well designed oil separating catch can system will establish a flow of air. You want a start where the fresh, filtered air can enter the engine and sweep through unrestricted taking the foul vapors with it to be caught and trapped in the catch can. I say fresh, filtered in the case of a vehicle like the Ford like the F-150 EcoBoost. If we were talking about the average GM product like a Camaro or Corvette then it would be fresh, filtered, metered air because they run a mass air flow sensor (MAF) but we’ll explain that shortly. Our system comes with a clean side separator, on most vehicles this replaces your oil fill cap. The clean side separator (CSS) provides ventilation with filtration and plumbs into your intake which keeps it a closed system so that you are not venting to the air. It makes our system EPA compliant and with dual filters inside prevents oil vapor from back flowing and causing oil ingestion. Most of the GM products today have breather lines to ventilate the crank case and while this is a good design it lacks filtration. This is where oil ingestion issues stem from on most of their vehicles. An oil separating catch can system alleviates this problem if installed by proper methods.

Another often overlooked requirement of an effective oil separating catch can system is the volume of the can. This alone is the number one reason why most catch cans on the market like a lot of the ones found on Amazon (for under a hundred bucks) are ineffective. The air comes in with the vapors and goes right back out leaving little if anything behind. Our standard size can is 16 ounces and our Monster can is a gargantuan 32 ounces, one of the largest if not the highest capacity can being sold currently.

Do we still have your attention? GOOD.

Aside from the volume of the can, the can must have properly designed internals so that vapors pulled into the can turn to liquid and get trapped without preventing air flow. Most catch cans have a central chamber with a heavy gauge steel mesh as coalescing media. Once enough vapor collects they form droplets that fall to the bottom of the can where they are trapped by dual baffles. The baffles allow air to pass by but not so much the liquid at the bottom of the can is picked back up and reintroduced to the engine. This seems like common sense to you but if you have one of those inexpensive cans you would be surprised at what you wouldn’t find inside. Here’s an example…


Now you’re asking yourself what the inside of a proper catch can looks like right? Well here’s one example in the illustration below…

rx catch can


Some years back there was a University of Maine study on Oil separating catch cans. The study showed that your average catch can like the photo shown above the illustration that can be purchased for under $100 is about 15% efficient at catching foul vapors. Then your higher end catch cans were about 45-55% when connected in between the PCV and intake manifold. A catch can with a clean side device to alleviate air flow restriction and a secondary vacuum connection was above 90% effective. Today, years later it’s the same story.

If you want the most efficient oil separating catch can system on the market, we sell the absolute best catch cans you can buy. Don’t wait any longer, buy one today! Just go to the top of the page and click SHOP