The Rondoggamus Maximus Oil Separator Project

    by
    SVTRonDogg
    Published on 01-29-10      Number of Views : 53  
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    This article explains why Oil Separators / Catch Cans are a good idea and provides several pictures to describe differences in oil separators and a how-to for installation. In an earlier post, RonDogg mentioned that he was working on a new solution to oil separation on this '03 Mustang Cobra, this is what he came up with...




    I currently run the Steeda Oil Separator. Nothing fancy, pretty much the same thing you can get for an air compressor down at Home Depot, and is the topic of many Do It Yourself Threads. It collects oil alright, but I think there are products that can do better. For my Test, I will be running my 'New' Solution inline with the Steeda unit in order to better gauge which is the superior unit.

    First, I took apart my Steeda unit, cleaned it thoroughly, and redid the hose barb fittings with teflon paste:








    Back to its position along the firewall plastic trim:



    The new unit is a much larger Air/Oil Separator from Stef's Fabrication (http://www.stefs.com/), Part #5122:


    This particular can has a 1/2 NPT inlet and a 3/8 NPT outlet. There are other cans available with different fittings, but I ordered this one based on availability. It is my understanding that if you order direct from Stef's Fabrication, they will customize the inlet/outlet sizes for your application. This is obviously the ideal situation.

    The PCV lines on the 2003/2004 Cobra are 3/8", which converts to -6AN size fittings. In order to use this particular can, adapters are needed, a 1/2 NPT to -6AN fitting, and a 3/8 NPT to -6AN fitting.

    A little more on how the can works:

    (preliminary fittings installed)
    The inlet is located at the front of the can while the outlet is located at the bottom. There is a drain petcock on the lower side of the can for drainage purposes. A look into the lid on the top reveals how the can works.




    Air travels through the inlet and is immediately met by the filtering media inside the can. There is a tube that runs from the outlet to the very top of the can. This tube is the only way that air can reach the outlet. As the air/oil mix enters the can, the oil gets trapped within the filtering media and is forced to drop to the bottom of the can. The 'clean' air is allowed to rise up where it reaches the opening of the tube and flows through to the outlet. This design allows for the can to become relatively full without contaminating the outgoing air. Both the filtering media and gravity will force the oil particles out of the air passing through and down to the can.

    Once the NPT to -AN adapters are in place, it is time for the hose fittings themselves.


    (NPT to -AN adapter)

    Initially I had planned on using a straight hose fitting to the inlet, and a 45 degree bend for the outlet. This proved to be difficult for hose routing from my chosen mounting location, which is basically wedged between the battery and the power distribution box. As you can see, the inlet hose interferes with the valve cover, I wanted more clearance:



    Originally I wanted to remove the Wiper Fluid reservoir and mount the can along the fender where the reservoir was. Removing the fluid tank was a little more time consuming than I had planned, so this is my somewhat temporary/permanent solution. Due to the size of my Optima battery, the tank fits snug and does not move at all. There is a proper mounting bracket made for such tanks by Moroso, which I plan to use at a later date.




    The fittings used are sourced from Aeroquip. The hose and fitting are from the AQP Socketless line. Assembly lube is used on both the hose and fittings, and the hose is pressed firmly onto the barbed hose fittings. I chose this line of product due to ease of assembly and reliability.











    Aeroquip AQP Socketless hose in the -6AN size used in this application is rated for -28in/hg of Vacuum, and 250psi. Probably overkill for this application, but I wanted easy installation and durability.

    Hose installed on fittings:





    As mentioned earlier, using a straight hose fitting for the inlet caused the hose to rub a little too close to the Driver's Valve Cover which I wasn't comfortable with:



    Luckily I had a spare 90 degree fitting in my parts pile. I switched the inlet to a 90 degree elbow and routed the outlet hose to the other side of the inlet (closest to battery) to give the hose more room.


    (Outlet hose was moved to the opposite side from this picture in order to gain more clearance)

    Can once again installed with new fittings:





    The new 90 degree fitting for the inlet gave the hose clearance that was needed.

    Running the hose between the PCV Valve and the Steeda separator:






    Final Connections:






    In a nutshell, this is how it flows:

    1. PCV Valve on Driver' Side Valve Cover to Stef's Inlet
    2. Stef's Inlet to Steeda Inlet
    3. Steeda Outlet to stock PCV tube

    The system is a bit redundant, but it is a temporary setup while I 'test' it. Ideally, I want to run just the Stef's can as I think it will provide superior filtration and require longer drain intervals over the Steeda.

    My hope is that with the PCV line passing through Stef's can FIRST, the Steeda tube will remain empty, verifying that there is really nothing left to Separate.

    The final product:




    Gear Head RonDogg Out