While I was in the process of cleaning the valves on my Mazdaspeed 3, I researched different ways that I could try to keep the plague of oil and carbon encrusted valves in the cylinder head to a minimum. The cleaning process is a rather tedious one, anything I could do to lengthen time between cleanings would be greatly appreciated, an ounce of prevention is worth a pound of cure and what not.
To get you all up to speed, allow me to extrapolate to the other readers who may not know why I would go to such lengths, the opportunity to explain. In a conventional automotive engine, the fuel and air is mixed pre-combustion chamber; the carburetor/throttle body opens, the air gets sucked into the engine as tiny jets in the carburetor/throttle body sprays fuel into the incoming air. The intake manifold is designed to swirl that air into a fine mist that gets pulled through the manifold, into the cylinder head, past the valves and into the combustion chamber. During this process, the wet air/fuel mixture washes over the valves in the head, which keeps deposits from the EGR (Exhaust Gas Recirculation) from sticking to the hot valves. Particulates are just washed back into the combustion chamber to be burned off. If you were to remove the cylinder head from the engine, the face of the valve would have some deposits built up but the stems and seats of the valve would have little, if any buildup.
The DISI (Direct Injection Spark Injection) motor in the Mazdaspeed 3 is a direct injection style intake setup. Meaning that the air and fuel are not mixed pre-combustion chamber, they are instead directly injected into the combustion chamber. The fuel does not meet the air until it is ready to be squeezed during the combustion cycle. DI is great for making power and better fuel efficiency, but it is bad for use with EGR and the valves. Why you might ask? Because unlike the previous example, there is no wet air/fuel mixture that washes over the valves to remove the vapors and particulates that get reintroduced to the cylinder head via EGR. Instead what happens is those vapors and particulates tend to stick to the very hot valves in the cylinder head, causing deposits to form on the stems and seats of the valves. Airflow can become blocked, valves may not fully close, MPG and performance begin to suffer. The only remedy for this situation is to remove the intake manifold and clean the valves. After finishing that laborious task, I decided to follow “ounce of prevention is worth a pound of cure” idiom and found some items to help keep my valves clean and my engine running in tip-top shape.
I first ordered a PCV plate ($150/$185 with factory Mazda PCV valve and gasket) from Damond Motorsports (damondmotorsports.com). As for what it does, it replaces the stock plastic PCV oil separator plate with a plate of milled Aluminum that has NPT ports which allows you to run different OCC (oil catch can) set-ups. The OCC’s connect to the PCV plate via the NPT ports. The Damond PCV plate accepts a factory Mazda PCV valve, and also has a channel for the factory Mazda gasket milled in! Damond Motorsports also throws in new mounting bolts, two 3/8 NPT fittings and plugs.
Damond Motorsports has a couple of blog posts on their website that talk about the various OCC set-ups you can run, from a single to multiple can set up. I highly recommend reading through those blog posts if you have no idea what you need. As well you can contact Damond Motorsports themselves, I found them to be super helpful ( I will provide the links to the blogs at the end of this article -R).
I decided to start small with my oil catch can set up and ordered the 2010-2012 Stage 1 for the Mazdaspeed 3 ($195/$215 with the VTA kit). The kit comes with an aluminum oil catch can, a high flow check valve/drain valve, mounting bracket and hardware, pre-cut hoses, hose clamps, and lots of zip-ties.
If you order the optional VTA (Vent To Atmosphere) kit, it comes fully assembled on the oil catch can. I decided to add the VTA kit for future proofing. There is a check valve contained inside of the air filter that opens to allow the venting of excessive crankcase pressure that can sometimes make it past the PCV valve under high boost, allowing you to keep vacuum in the crankcase. When you are driving the car under boost conditions, the boost closes the check valve, not allowing any boost to enter can. When the check valve closes, excess pressure is forced to find a place to vent. Giving the can a filter with a check valve allows the pressure an easy place to vent while maintaining the ability to keep crankcase vacuum under normal operation, which is needed on a street driven car.
What it does for DISI equipped vehicles (Gen 1 & 2 Mazdaspeed 3, Mazdaspeed 6) is help the PCV system to run more efficiently. Sometimes the PCV valve and stock rubber hoses can become clogged with oil particulates and contaminants from crankcase gases (that usually end up sticking on to the valves in the cylinder head) which will prevent the PCV system from working properly. The PCV system can’t vent the gases properly, crankcase pressure begins to build, which can block or impede the oil return line from the turbo. Pressure will seek the path of least resistance, which in the case of the turbo means oil leaking past the turbo shaft seal and dumping oil into the hot side, leading to a smoking turbo or worse, turbo failure. I decided the positives of the system had merit and the extra $25 spent here could save money later on.
You can order the hoses in one of three colors (blue, red, and black), and the hoses are oil and vacuum resistant. When you order the kit, you have a choice of two mounting locations, which determine the amount of hose that is needed. Since Damond Motorsports pre-cuts the hoses, it really makes this a bolt-in affair. Everything that is needed for install is supplied in the kit, I didn’t have to make an unnecessary run to the parts store!
Installation was straightforward as you can see in the PCV and OCC installation video here on the site. Everything went together smoothly with the only issue being the factory bolt in my mounting location being seized. No check engine lights or engine issues after installation either. I am really pleased with the setup and as I add more parts, I can update the system with another OCC in the future.
Long Term Update:
July 3rd, 2018
It has been about a year since I installed this on my car and I have had zero issues with the setup. I recently did an oil change and this is what I drained from the catch can:
Clearly the system is working and doing its job! Recommended intervals for checking and draining the oil catch can is 3000 – 5000 miles or at oil change time. I check mine every 1500 miles or so (my car is a summer/warm weather car), if your car is a daily driver you might want to check it more often, especially in the winter.
I have been really pleased with the setup overall and I like the fact that I can adapt and expand the system as my car evolves through tuning. If anyone is looking for a well made oil catch can and PCV plate, I highly recommend dropping a line to the guys at Damond Motorsports!