How Killer B Motorsports Can Save Your Subaru's Engine

    21 DEC 2023 - Jeff Willis

    In terms of fabrication in the Subaru performance industry, Killer B Motorsport not only set the bar, but grabbed the bar, and threw it to the stratosphere. They are artists at their craft, and above anything else they are Subaru enthusiasts. In the manufacturing process, Killer B’s products are the result of the latest state-of-the-art CAD software that are paired with premium materials, and at the highest level of production value. With many years invested in the Subaru platform, Killer B Motorsport has addressed some of the weak points in the EJ engine with solutions to increase the overall longevity during high-performance driving conditions.

     

    HOW COULD KILLER B PRODUCTS SAVE THE ENGINE IN YOUR SUBARU STI?

     

    The EJ flat-four engine in the Subaru STI does have inherent oiling issues, as do any flat-style engine layout. Although some issues are more prevalent in high-performance driving conditions, they should be addressed either way.  Through years of experience, Killer B Motorsport is very familiar with the weaker culprits in the EJ engine. They have strategically designed components that are stronger and will relieve many of the issues that can plague the flat-four engine in your Subaru STI to improve the overall longevity for your street car, or purpose-built race car. 

     

    THE DESIGN OF THE EJ’S PCV SYSTEM:

    One example is the highly documented design of the PCV system. Oil, contaminated oil, oil vapors, or a combination of everything could make their way into the intake system of your STI. When this happens, you may not see any engine damage, or any running issues at first. It will be a problem for those of you who don’t address this issue, and drive 20k+ miles a year if you use your STI as a daily driver. There are two major areas that can be affected if this happens. If the oil makes it to your intake valves, eventually you will have excessive carbon buildup. Where things can ready get sideways, is when the oil can make it past the intake valves and starts coating the tops of the pistons. This can cause detonation issues because the oil will lower the octane rating in your gasoline. And if you’re one to frequently lean on that gas pedal, the engine damage can also accelerate.

     

    WHAT IS THE SOLUTION?

     

    The solution is a proper air oil separator. An air oil separator works with the routing of your PCV system, and routes oil, as well as any contaminants into a catch can, or back into your oil pan. The objective is to collect the oil before it has a chance to reach your intake system. This means that your intake valves are free of carbon buildup, and your cylinders are clear of any oil so that your air/fuel mixture can remain in the strike zone.  The Kille B Motorsport Air Oil Separator Kit will include everything needed to complete the installation, and to prevent oil from getting into your intake system. Their kit is a unique centrifugal filtration design that separates oil from the contaminants. The collected oil will drain back into the crankcase where the contaminants will get collected into the catch can. The design also applies vacuum to the crankcase which improves the overall ring seal, reducing oil consumption while improving your power potential.

    Here are some examples that are available for your STI:

     

     

    THE DESIGN OF THE OEM OIL PICKUP:

    A very scary design indeed that can end your engine. Now is this problem large enough that it has created Subaru recalls? No, but it is a documented issue that should bee addressed especially if you are investing in a new or rebuilt engine. What is the oil pickup? In a nutshell, this is a tube that rests near the bottom of your oil pan. It collects oil and with oil pressure, sends the oil off into the rest of the engine where imperative lubrication points such as your engine bearings can receive a proper amount of oil. The failure point on the OEM oil pickup is that the joint welds. The combination of the engine vibration, as well as the road vibration or even the oil pressure can cause the welds to crack on the OEM pickup tube. When this happens, the oil pickup tube will suck in air rather than oil. A loss of oil pressure will occur, and you will also have a loss of oil lubrication causing friction in your bearings. This means that you will be rebuilding your engine.

    However, if you are rebuilding your engine, take the time to upgrade your oil pickup tube. Replace the surrounding components as well (we will get there later in the blog), to reduce further oiling issues in your EJ.

     

    KILLER B’S FIX:

    The Killer B Motorsport Oil Pickup features high-strength DOM steel construction that is 3 times thicker than the OEM oil pickup. Additionally, it is considered to be one of the highest flowing EJ oil pickups on the market. Although durability was the main objective in the design, Killer B designed this pickup with high -strength double gussets, ported internal passages, and an enlarged inlet with anti-funneling geometry to increase the oil flow. Full TIG-welded throughout, this will be the last oil pickup you will need. If you are in the middle of an oil change, this modification can be performed by removing your oil pan, or you or your engine builder can simply perform this upgrade while your engine is propped on an engine stand.

     

    Here are some examples, and note that you must upgrade to Killer B’s Oil Pan (details below):

     

    BAFFLING:

     

    There are a few videos floating on YouTube of Subaru STI models doing donuts in a parking lot, and suddenly, the pistons are on the ground. How in the world does this happen? Flat engine problems that’s what happened. In this case, the engine stays in the upper-RPM range while the oil is pushed to the other bank of the engine. The problem is that the other side of the engine is getting starved of oil and lubrication. When your engine is revving high and if it lacks lubrication, friction will happen, and you will lose an engine. So, if you participate in weekend track days, autocrosses, or in any high-performance driving events, you risk putting your engine through long periods of lateral loads. If your local track has high banks where the law of physics sets your oil on one side of your engine, then you should invest in a baffle.

    Killer B’s solution prevents excessive oil sloshing from one bank to the other during cornering, as well as braking to keep the oil as central as possible. Now Killer B offers these in packages that include a larger oil pan and the upgraded pickup. But for those of you who just need the tray alone, we have that option available:

    KILLER B MOTORSPORT OIL BAFFLE WINDAGE TRAY – SUBARU MODELS INC. 2002-2014 WRX / 2004+ STI

     

    CONTINUING WITH OIL PROTECTION:

     

    Killer B Motorsport does offer a larger oil pan option for your STI. This is an ideal upgrade for those of you with WRX models upgrading to an STI-style exhaust manifold, it is also required when upgrading to certain Keller B Motorsport Oil Pickups to have proper clearance. And one of the biggest benefits are that the Killer B Oil Pans will host an additional 1.4 quarts of oil to have a 30% increase in the overall capacity. This increases the overall oil protection during high-performance driving conditions. More importantly, it has the size needed to clear the Killer B oil pickup and windage tray. And although you can purchase the oil pan separately, it is best to invest in all (3) components (the oil pan, pickup, and baffle windage tray) together to provide your EJ with the ultimate in oiling protection.

    KILLER B MOTORSPORT ALUMINUM OIL PAN PACKAGE – SUBARU MODELS INC. 2002-2014 WRX / 2004+ STI

    KILLER B PERFORMANCE SUPER G PERFORMACNE OIL PAN W/HIGH FLOW PICKUP AND BAFFLE (40% INCREASE IN OIL CAPACITY) – SUBARU MODELS INC. 2002-2014 WRX / 2004+ STI

     

     

    THE VERDICT:

    These particular upgrades brought to you by Killer B Motorsport will increase and improve your engines longevity, protection, and performance in your Subaru STI. At minimum, you should perform the air/oil separator to prevent carbon buildup and oil buildup in your intake system. This protects your EJ for both daily driving, and high-performance driving conditions. When you find yourself adding more upgrades that increase the power and the torque, and if you participate in weekend driving events that have many shifting corners and turns, and if you just invested in a forged motor rebuild, then you need to also invest in proper oil protection. The Subaru STI is one of the most coveted rally-inspired all-wheel-drive vehicles on the market and it’s hard not to drive these cars spiritedly. But the EJ is not bulletproof, and if you want your engine to last, then you must address the inherent oiling flaws within the engine. With the years and countless hours invested in the EJ platform, Killer B Motorsport is very familiar with Subaru’s engine culprits, and they have the right resolution with a solid product for your Subaru.