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Alloytec PCV

Discussion in 'Holden Commodore How-To's' started by Fu Manchu, Oct 31, 2019.

  1. Fu Manchu

    Fu Manchu Well-Known Member

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    I did the PCV mod.
    Had a spare valve cover. Gave it a go.

    Amazing difference.

    Pulled the spare off with a claw hammer. Plucked it out easy. But you can’t do this when it’s in the car.

    In the car, use visegrips. Put a thick cloth over. Lock the grips, twist back and forth and pull.
    They are in with dob of Red thread lock.

    To get the PCV hose off, there’s a tab to use. Press in? Out? Can’t recall.

    I checked out the Camaro forum. They say 5/64ths and 7/64ths are the drill sizes to use.

    I converted that to 3mm for the top hole and 2mm for the bottom.

    Soaked the valve for a few days (forgot about it) Throttlebody cleaner evaporated. Left this muck 0C825B00-2BCD-4BC4-A1FF-A27216DC410B.jpeg

    It (the wrecker spare) was clogged solid. Couldn’t see through. Heaps more came out after this. Did many many soaks and cleans.

    Got it super clean.

    Drilled the holes. After this, getting the straw on the throttle body cleaner inside the valve was easy. More schmutz came out. Bits of carbon. Easy to get the metal out after drilling.
    Another soak and in it went into the VZ.

    The one that came out was ok. Not clogged. Could see through it.

    Didn’t expect anything to happen.
    However each day, the idle and revs smoothed more and more.
    Always has trimmed revs as you drive. The tacho gauge just twitches up and down. Bugged me. Not anymore. It’s pretty much steady as now.

    Vacuum seems better. Why??

    Smooth acceleration. Smoother than Barry White walking in yogurt.

    Would recommend to everyone.

    There were no changes made or fuel added during this change.
    I take it the ECM has been slowly relearning fuel trims now the crank case gassed are flowing better.

    I didn’t get any data before hand.

    Will be doing this on my VE Calais now that the VZ is super happy with it.

    Again, it was a pleasant surprise.

    This came from my VZ one (much cleaner) 085FB644-0291-4D1C-958E-91816C284721.jpeg

    Fuel consumption improved as well.
     
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  2. Fu Manchu

    Fu Manchu Well-Known Member

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    I’ll take before and after photos of the holes on the PCV on the next one.

    GM apparently corrected the undersized PCV holes sometime after 2013?

    Can you buy a PCV with factory enlarged holes?
    Yes. It costs a Shinto load because it comes with a free valve cover.

    Thanks GM ya f%^#ers.
     
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  3. scaredyet

    scaredyet Member

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    I'm interested in this one
     
  4. Fu Manchu

    Fu Manchu Well-Known Member

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    3E2F0F25-BEFD-4FEC-B027-E9C9E4D40D9B.jpeg So I did the second one that goes on my VE Calais.

    This PCV came from my VZ. (I used a spare on that)

    Of note is that the two holes are actually slightly different sizes. A smidge under 1.5mm.

    You can see the bits of red thread lock.
    (Remove: Visegrips, rag over the PCV, twist back and forth, then pull.)

    D221253E-4A1A-4105-BEB0-6758EA4C3CB5.jpeg
    You can see the mark left on that ridge from the vise grips, so hence why I suggest a bit of rag over it.

    7BD1794B-7BD1-4447-8CAD-87A538003594.jpeg

    B5DAA606-E462-48EB-938D-A6BEFDCCD33D.jpeg

    You can see the holes are small.

    Drill 2mm for the bottom and 3mm for the top.

    8CA9ABE7-C391-4E25-B834-1AD74BEEA9DB.jpeg

    47210EA4-FC44-4AB0-89B3-8EF8EBA885DA.jpeg
    I did drill 1.5mm for one hole and 2mm for the other, but considering it isn’t written anywhere that the two holes are different sizes (or why) I said “meh” and did the other at 2mm as well, like I did on the first one that went on the VZ.

    D20D57BE-5457-4F41-B2C0-9CF59E2EE407.jpeg
    Top at 3mm.

    I used a magnet to clean up swarth and then a good squirt of throttle body cleaner through it. The straw fits down the holes now.

    2EACD1F0-661B-4E7D-AC30-9470BB5D7138.jpeg
    To reinstall, I used a 12mm deep set socket.
    E2728D28-E911-4270-96DD-2D8F76979876.jpeg
    Tap it in gently with a small hammer. A short socket extension helps make it easier to tap in.

    *It should remain harder (more resistance) to blow through from the top than it is to blow through from the bottom. (Had to be careful how I wrote that)
     
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  5. Dayvo

    Dayvo Because i can

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    Is the pcv valve on the lfx motor on the rear right hand side valve cover ?
     
  6. Fu Manchu

    Fu Manchu Well-Known Member

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    9F286439-C028-414A-A9AE-B2CFE47D2FAF.jpeg

    F8484010-B0BE-4314-903E-8399AC5BCCD6.jpeg
    This is what I pulled out of the VE.
    Gunked up as!
    I used the one I pictured earlier.
    Came out easy as too. Could have used pliers.

    So used a cleaned and modified spare in the VZ.
    Pulled the VZ one, cleaned it and modified it. Used it in the VE Calais.
    Can't say I have ever done many things on a car as simple and easy to do as this, that has made such a difference to way the car drives.

    What a difference to drive! Instant change. Wow. Much smoother. Will get better as fuel trims improve in the next week or so.
     
    Last edited: Nov 3, 2019
  7. Fu Manchu

    Fu Manchu Well-Known Member

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    From what I can tell, yes. Same place.
     
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  8. 99notout

    99notout Active Member

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    Great write up, really clear and sharp pictures, thanks! Can you let us know if you end up with more oil in the intake? Interested to know. Cheers.
     
  9. Fu Manchu

    Fu Manchu Well-Known Member

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    To clear up something, the valve cover does not need to come off.
     
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  10. immortality

    immortality Home of the smoky breakfast Bacon! Staff Member

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    Have moved this to the How-to section.

    Every person with an Alloytec needs to do this mod.
     
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  11. Dayvo

    Dayvo Because i can

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    What about people with the sidi , will they benefit from this mod too ?
     
  12. immortality

    immortality Home of the smoky breakfast Bacon! Staff Member

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    Somewhere along the line GM modified the PCV valve I believe much like this but I'm not exactly sure when that happened but I'm fairly sure it was only done in the last couple of years. It couldn't hurt to pull it out and check and you might as well clean it out whilst you are there.
     
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  13. Dayvo

    Dayvo Because i can

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    Had a look at the one on my lfx motor and looks like its made of plastic with a right angle connection with a hose connected that runs into the catch can .
     
  14. Fu Manchu

    Fu Manchu Well-Known Member

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    8FD6B621-C3FE-42DA-A360-F30727D76CBD.jpeg
    This is the hose and valve location on VZ-VE S1 (guessing similar on VE2-VF in various configurations)

    61395E1C-ACC2-4459-9EB2-D1E25487C15B.jpeg
    I have pulled the heater hose aside and there’s a plastic tab on my finger which needs to gently be pushed toward the passenger side and the hose lifted to release it.
     
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  15. Fu Manchu

    Fu Manchu Well-Known Member

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  16. Fu Manchu

    Fu Manchu Well-Known Member

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    1E304C94-C1D4-4728-978C-010204A37CE7.jpeg This is what came from the VE valve.
    Soaked in throttle body cleaner and the cleaner has evaporated away leaving this.
     

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  17. lmoengnr

    lmoengnr Well-Known Member

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    That looks pretty manky...
    We know the V6 PCV systems are basically inadequate, but what about the root cause?
    Why are the V6's such heavy breathers?
     
  18. 1985VK

    1985VK Well-Known Member

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    Time for a catch can
     
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  19. immortality

    immortality Home of the smoky breakfast Bacon! Staff Member

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    I wouldn't say they are heavy breathers, if anything the LS series of motors is worse. All engines breathe, it just depends on how well those gases are filtered before they go back into the intake that matters. GM tried to improve the PCV system on the later LS motors by adding a filter system under the the valley cover where the breather pipe comes from.

    One reason for increased blow-by may be the use of low tension rings, less friction = less parasitic losses but might = more blow-by in the long run? If you really want to run low tension rings it pays to have a crankcase vacuum system as the vacuum helps to seal the rings against the bore but now we are getting into race car territory.
     
  20. greenacc

    greenacc Searching for the billion

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    I don't think they breathe any heavier than other engines, just the pcv is so small.
     
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