Engine Oil Separator Questions

Discussion in 'SN95 4.6L Mustang Tech' started by Mattstang04, Nov 5, 2013.

  1. I have noticed while shopping around PCV oil/air separators that the only one specifically made for 2 valve 4.6L is the Moroso unit with the drain on the bottom (which I have already ordered). The Steeda kits and other various brands are designated for 4 valve only and appear to mount in line from the left valve cover instead of the PCV line on the right side valve cover. What is the deal?

    Can you splice in the separator on the left side and it work on a 2 valve? Does it have something to do with forced induction? Is there any benefit to running one off both sides?

    My desired end result is no oil blow by into my supercharger or anywhere for that matter. I also noticed that the supercharged generation of the Ford Lightning (which are 2 valves) have the left side oil separators available to purchase.
  2. I plan on running a JLT separator in the near future. There's a youtube video of someone testing a JLT, UPR, and Moroso separator on a Coyote and the JLT performed the best by far.

  3. That picture shows a 2v for sure. I wonder if I should run one on each side?

    I'm going to run my Moroso on the right side in between the PCV and Plenum connections. Perhaps an additional JLT or Steeda on the right if I do not get the desired effect.

    Or do you think I should hook up the Moroso on the right side?
  4. It's interesting that you say that. People compare us (UPR) to JLT all the time... but I have a customer who had a UPR can, replaced it with a JLT can because he liked JLT's lines better, then he noticed that the can wasn't trapping as much oil. So he sold the JLT can, bought another UPR can, and now he's back to normal.

    I guess if anything, this just shows that the test of which one is more effective at trapping oil vapor can turn out either way.
  5. I could be wrong, but I don't think it would matter which source you connect it to as long as it vents the crankcase. I also don't believe that you'll see increased efficiency if you run one on both banks. I could be wrong.

    I take that back. The UPR unit wasn't being compared to the JLT unit at all. It was a comparison between the JLT unit and the Shelby America and similar designed units. The UPR was actually praised and considered to function just as well as the JLT piece. Does your separator feature a filter like the JLT?

    BTW it was JLT themselves that made the video Im referencing.
    Sharad likes this.
  6. I will let you know how it goes with the Moroso. It should be here later this week. Thanks for the responses. I will try to find that YouTube video as well.
  7. It does make a difference which side the oil separator is installed. On the SOHC 4.6 V8's the right hand (passenger's side) has the vacuum applied to the valve cover. The left hand side (driver's side) is for MAKE UP air.

    Any oil vapor would only be present in the vapors pulled from the right hand valve covers via the PCV valve.

    There would never be any oil vapor in the left hand side line (make up air). It would be a waste to install an oil separator there.
    trombonedemon likes this.
  8. Thanks for the info burns. So while I got you, I'm installing this separator to eliminate the oil that is accumulating in my supercharger air intake. The hose running from the left valve cover to the supercharger air inlet is the guilty culprit for dumping in the oil vapor.

    You are saying as long as I hook in the separator to the right hand valve cover/ PCV line, I will eliminate this blow-by into my supercharger?
  9. Yes, UPR's can uses a filter system. It traps a little bit of oil...

  10. Not to contradict what Burns said but I've seen blow-bye on my oil cap, it does makes it way through the drivers side. Make sure those hoses dont collasp under the vaccum pressure or else you will be changing a valve cover gasket, those are not fun....
  11. Mine too, trombone. Lot's of oil on the driver's side. Not so much on the passenger side. Here is how I set mine up.


  12. Glad to hear I am not the only one with this issue.
  13. Guys. IF you have excessive blow by on the left side (make up air) of the motor, then this means either:
    • The blow by vapors are not being removed by the PCV on the right hand side. IE, the line is blocked or the PCV is stuck closed.
    • Or there is SOOOO much blow by vapor it's completely over whelming the capacity of the PCV system to remove the vapor.
    Think about it for a moment. For a significant amount of vapors to come out of the make up line would require the pressure inside the line to be higher than atmospheric pressure. This implies that the internal crank case is under pressure. This shouldn't be as the PCV system is designed to keep that from happening.

    IMO excessive blow by is a symptom of an underlying problem.
    #13 wmburns, Nov 12, 2013
    Last edited: Nov 13, 2013
    trombonedemon likes this.
  14. Was led to believe that if there is excessive blowby the there is a possibility that the piston-rings need to be replaced.
  15. I hooked the separator into the right side/ pcv side. I will keep an eye on it and see if the condition improves.
  16. I don't get any blow-by any more with my separator in place. I can even leave the hose off of the left valve cover and I get nothing. I guess I should add my car's PVC is deleted.
  17. Can anyone tell me what the deal is with the electrical connection on my PCV valve? I've never been clear on why it is there. I assume it heats it for some reason but never dug too deep to find its reason for existence.
  18. Heated PVC value. Prevents water vapor from freezing and blocking the PCV system when it's cold outside.
  19. Makes sense now that I installed my separator. The engine was built with the PCV system deleted and had breathers installed and I was getting a lot of oil on the drivers side valve cover. Not that the separator is installed I have a clean cover now.