Mishimoto Compact Baffled Oil Catch Can, Part 1: Product Introduction and Initial Design

Mishimoto Compact Baffled Oil Catch Can, Part 1: Product Introduction and Initial Design

Interested in purchasing this catch can? Check out our product page for more information!

Mishimoto Compact Baffled Oil Catch Can

Initial 3D rendering of Mishimoto Compact Baffled Oil Catch Can
Initial 3D rendering of Mishimoto Compact Baffled Oil Catch Can

So we asked ourselves, what makes a catch can appealing to the masses? In a market swamped with extremely low-priced options, a new product could easily get lost in the mix of products already available. Our team began sifting through forums and asking our contacts at local shops to see exactly what they wanted from a catch can. We also reviewed our current line of products, to see if we could develop a new design that would fit within our current offerings.

An efficient catch-can setup is not generally perceived as a product that will impact engine performance or power. This is not true at all! A catch can will make a significant impact on the cleanliness of the intake components, including the charge air cooler (CAC) system, as well as reduce detonation within the combustion chamber. Oil coating the internal components of your intercooler will have a significant impact on heat transfer, reducing the effectiveness of the cooler. By adding an oil catch can you would be improving the reliability and overall performance of your engine. Power gains might not be noticeable, but over time your engine will benefit from running cleaner. The real-world results also show us that a majority of consumers are going to be price-driven, so we would need to consider this as well.

We uncovered a group of consumers who were very concerned with actual product results. Many of them have expensive engine builds and want to be proactive in finding a solution for removing the largest amount of contaminants possible to protect their investment. Another key element was styling, strangely enough. This product is normally quite visible within a vehicle's engine bay. Unique, engineering-based styling seems to really grab the attention of those peering inside.

So, you may be wondering: How can my car benefit from a catch can? Is the product a gimmick? Will I truly notice the difference? All are great questions. Let's first take a look at the functions of a catch can.

A catch can? Why do I need one?

The car didn't come with one from the factory so why do I need one? This is a common question from newbies to the performance automotive world. On your factory PCV/CCV system, fuel and oil vapors pass through lines that make their way into your intake. The engine will then burn off these vapors in the combustion chamber. Although this process eliminates the need for a catch can and is generally considered normal practice in the automotive world, it does have a few downsides.

  1. Oil buildup in the intercooler will reduce cooling efficiency.
  2. Oil burning in the combustion chamber will lower octane levels and promote detonation.
  3. Contaminants will build up in the throttle body and intake manifold.

Why wouldn't a manufacturer use a catch can, considering the negative impacts above? Well, I would assume the primary reasoning is simplicity and user friendliness. A factory-installed catch can would require emptying on a regular basis. Let's face it, we humans are lazy. It is tough enough for vehicle owners to remember or even want to change their oil during the correct service intervals. Asking them to empty a catch can would be laughable. Emissions also plays a role in routing CCV vapors back into the intake. The most environmentally friendly way of eliminating these vapors and byproducts is to burn them in the combustion chamber. This keeps the system fully contained. This principle has been a standard for quite some time in both diesel and petrol applications and will likely remain so.

The catch can plays an important role in engine longevity, engine cleanliness, and efficiency of both the combustion mixture and the intercooler system (assuming your vehicle is turbocharged). The catch can mounts inline to the hose that returns to the intake system and works to separate the contaminants prior to their entry into the intake. Air enters into the catch can, where the vapors will be filtered and condensed to promote separation. In theory (and in a proper functioning setup) only clean air will return to the intake, thus protecting your engine from these harmful elements.

Now, why do these gases exist? In simple terms, during engine operation air will flow past the piston rings and into the crankcase area; this is referred to as blow-by. This is unavoidable, as a perfect ring seal is impossible to achieve. Because this air is passing into the crankcase, it will need to be vented to prevent issues. A pressurized crankcase with no relief will result in leaking engine seals, a loss of power (due to its affect on piston movement), oil flow past the rings (resulting in a nice white smoke cloud), and several other major concerns. It is imperative that this air is released in an effective manner. Additionally, modern systems utilize a vacuum source in the CCV system to keep a pull of airflow on the ventilation line.

You may be asking yourself, why don't I just vent these vapors into the atmosphere? Why return them to my engine at all? Because you are an environmentally conscious individual, that's why. Returning these oil vapors/liquids to the air is harmful to the environment and terrible for the roadways. Be responsible, keep your vapors to yourself.

Now, don't assume that these setups are necessary only for turbocharged applications. All engines produce blow-by, some more than others. For example, one of our team members drives a K-series Honda that seems to burn quite a bit of oil, which makes him the target of a reasonable amount of oil jokes during lunch. This also makes it easy for us to find a test vehicle for our new catch can.

Now that we have a general idea of how this component functions and the benefits, let's jump back into the development of our product.

Project Guidelines

With general information gathered from our customer base and vendors, we began by setting guidelines for our team of engineers to create a catch can that would awe enthusiasts and help extend the life of our customer's engines. Check out our list below!

  1. Primarily focus on air/oil separation
  2. Smaller footprint than our current baffled catch can
  3. Include a baffle system
  4. Universal mounting system for easy installation
  5. Unique, subtle styling
  6. Develop both a two-port and a three-port catch can

Let's break these down and expand a bit on each particular project target.

Function Over Form

We love products that look great, but the appearance is negated if they do not function to the fullest. Our primary goal for any product in development is to ensure that it works, and works well. If we can squeeze more performance or functionality out of a component then we will. If we can make it bigger, cooler, more efficient, add new features, or innovate it in any way, our team will do it. For this particular project we will be focusing our performance target on the separation of oil/fuel particles from the CCV/PCV system. We know you are purchasing this product with the anticipation of a clean intake and charge air tract, and we are aiming for that result with our product. Our existing baffled oil catch can utilizes a bronze filter incorporated into the top of the can to separate contaminants. We have found that this setup works extremely well, and our team will use this knowledge to develop our new can. We will be testing this new unit as well, and we will be ensuring that this product performs and protects to the best of our abilities.

Size Matters

Size, a common discussion point surrounding a variety of automotive components. Everyone wants an intercooler the size of a Fiat 126 and a massive turbocharger that frightens small children and instills jealously among other enthusiasts. For a catch can, size is relative to the needs of your particular project. Being that we already offer a larger-sized baffled catch can, we found that some of our consumers would prefer a more compact setup. The need for a smaller can also coincides with the space constraints in the engine bays of modern-day vehicles. Components are getting smaller, lighter, and closer to other engine bay elements. With vehicles in and out of our shop on a regular basis, we have been able to gather some information regarding allotted space for additional components in the WRX, STI, E90, E46, GTO, Powerstroke trucks, Cummins trucks, and more. Our existing oil catch can features the dimensions shown below. Our compact baffled catch can will feature a smaller footprint to better suit the engine bay of modern/sport compact vehicles. Check out the dimensions of our existing baffled oil catch can.

Dimensions of existing Mishimoto Baffled Oil Catch Can
Dimensions of existing Mishimoto Baffled Oil Catch Can

The larger size provides this can with a capacity of 9 fl oz, ideal for use in engine bays with greater space. It also extends the intervals for users to empty the catch can, which is actually quite an easy task with our unit. So in short, we will be developing a catch can with similar features and components to this larger unit, but in a much smaller package.


A baffle … why would I want a baffle? The inclusion of a baffle in our catch can provides a huge benefit in the performance aspect of the design. A baffle provides for a more effective product that functions much better than the wad of steel wool found in a majority of DIY or inexpensive catch can solutions. Not to put a negative tone or implication on the performance of such a catch can, as these can still be effective, but a properly designed baffling will allow the oil to condense correctly. By adding a baffle we are increasing the internal surface area of the can and providing more locations for the oil vapors to condense. All of this results in greater separation of particles and a cleaner intake for your car. Additionally, the baffle will provide protection from collected oil splashing upward against the filter, which could occur when driving over bumpy terrain or cornering in a high g situation. Our new catch can would have the most effective components we can possibly design, hence the baffle. Although this will translate into a higher price, the improvements are certainly worth the increase in benefits to your vehicle. We will have more information on our baffle design during our second stage of development.

Mount It

Mounting your new oil catch can can be the most challenging part of installation. Our goal here is to provide a can with easy-to-use mounting brackets that will provide as much flexibility as possible. Everyone has a different set of engine bay constraints and locations for mounting, so our hope is to provide one unit that will fit all applications. Additionally, we can probably convince our engineering team to get a bit creative and design these mounts in a unique fashion that screams innovation.

One of our plans with the bracket is a three-slot design. This will allow for a mounting bracket that can swivel nearly 360 degrees to provide the best angle for your inlet/outlet locations. More on this later!


Along with creating a product that performs well, we will want this catch can to look the part. Our team has a way of developing products that are subtle, clean, and unique. We are automotive enthusiasts ourselves, and we understand that all consumers differ on this particular aspect. Our goal is to provide a nice design that satisfies the tastes of as many folks as we can. With our existing product design track record, you can assume this catch can will be quite the looker.


Our goal here is to develop both a two-port and a three-port catch can. Why would we want to do this? A traditional catch can utilizes one entry port and one exit port, making it a two-port can. CCV air enters the can, is filtered, and returns to the intake tract. We have found that numerous vehicles, such as the Subaru EJ, utilize dual crankcase ventilation lines that necessitate use of a dual-entry can. We will design two catch cans with very similar features, differing in just the inlets. This should provide some flexibility and ease of installation for customers with such CCV systems.

With our guidelines in place, our team began developing 3D renderings using Solidworks software in an effort to produce a basic shape for the project. After several design iterations, we finally came to the rendering you see below.

Initial 3D rendering of Mishimoto Compact Baffled Oil Catch Can
Initial 3D rendering of Mishimoto Compact Baffled Oil Catch Can

Now that we had a basic outline for the project, we could begin fabricating components and utilizing our 3D printer so we could visualize the can and ensure its features would suit our needs. Check back next time where we begin constructing prototypes!

Interested in purchasing this catch can? Check out our product page for more information!

Mishimoto Compact Baffled Oil Catch Can