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4g63 Block Vent

Posted by BogusSVO, Nov 12, 2013

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  1. BogusSVO

    BogusSVO Proven Member

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    4G63 Block Vent

    I have read a few threads on adding a block vent to the 4g63.
    I know this not a new idea, and others have had done it before.
    I also know that there is a kit so a block vent can be added in at the rear balance shaft timing passage.
    Some of the locations I have seen used I did not like, or the size of the fitting being too small to be very effective.
    After spending some time looking a block over, and looking at an assembled engine. I believe I found one of the better spots to install a block vent.

    If you have not read this thread.
    http://www.dsmtuners.com/forums/cyl...ook-4g63-pcv-system-engine-internal-view.html
    You should do so, so you will have a better understanding of why I chose the location I did.

    Since there is a factory vent from block to head, tapping into this spot makes the most sense to me. It is on the down side rotation of the crank, and is decently covered and high enough in the block not having to worry about oil slosh or oil return from the head. Also this should pull from the head as well as the block.
    049_zps70fe1501.jpg

    Also looking at an assembled engine, this vent looks to clear the starter and the intake support bracket.
    059_zps87a1b23f.jpg

    I chose to use a 1/2npt 45* fitting with a 5/8 hose barb. This should give plenty of cross section and make an effective vent. The ID of the fitting is .530 The reason for a 45* instead of a 90* is so there will be less of a flow restriction through the fitting.
    057_zps9d1ffc64.jpg
    I scribed a simple circle for the location, then did a center punch dot
    056_zps60466cba.jpg

    It is a basic drill and tap install.
    For a ½ npt the drill size used is 23/32

    062_zpsca09b703.jpg

    Then tap a few thread, care needs to be used since this is a thin cast area.
    064_zpsb8807539.jpg

    Test fit the vent fitting and tap until the proper angle for the hose fittings face the desired angle.
    065_zpsf78b6ebf.jpg

    Try not to extend the threaded portion of the fitting into the factory vent passage.
    066_zpsd61d14f4.jpg
     
    Last edited: Nov 16, 2013
    punk3rz, ceedawg and keltalon like this.
  2. Kirkamus

    Kirkamus Proven Member

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    must say and sorry for spam but I rank you among the best knowledge base people on engine rebuild/machine workers <3 the work
     

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  3. AllanL

    AllanL Proven Member

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    sorry for being lazy to search...

    ...but please let us know the purpose of such a vent?

    thanks!
     
  4. 1qkfwd

    1qkfwd DSM Wiseman

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    Better crankcase ventilation which our engines lack.

    That spot looks good since it'll allow pressure out and not fight with oil drain back.

    You need to really get creative and see how we can improve drain back. Then we would be set.
     

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  5. AllanL

    AllanL Proven Member

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  6. nitrouskris

    nitrouskris Proven Member

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    Again another great write up
     

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  7. turbotalon1g

    turbotalon1g Proven Member

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    How many miles on this setup?
     

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  8. LandSpeed-DSM

    LandSpeed-DSM Proven Member

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    Agreed, that is a good spot! I have to think that 1/2" or -8 for the entire crankcase may not be enough though, anything better than none of course!

    Anything that keeps blow-by out of the oil return galleys will improve drain back. Simultaneously venting the crankcase and the head is really the only way.

    I've begun to believe that only improving flow out the valve cover may actually make things worse, as far as returning oil is concerned. Because the oil now has to fight the same volume of blow-by gas, but with a greater pressure differential between the block and head.

    Another spot I am looking to try out next spring is the front balance shaft hole, with a -12. Obviously this is only an option on BSE engines. Both of these along with the two -10s coming out of my VC, with vacuum supplied by the -12 ahead of my turbo should do the job fairly well for a non-drysump setup.
     

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  9. BogusSVO

    BogusSVO Proven Member

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    LS-D, Glad you like the spot I picked! I stood in the fittings isle looking at both the 1/2 npt and the 3/4 npt fittings.

    I bet you know the thread that led me to look into this mod.:aha:

    http://www.dsmtuners.com/forums/newbie-forum/471722-pvc-port-4g63-block.html

    I will say to anyone who wants to do this mod, the engine must be fully apart. I would not even think about doing this "In car" even with the grease method on the drill bit and tap. To me there is just to much risk of cast iron chips to end up in the oil pan.


    This thread will walk you through the vent system inside the engine.

    http://www.dsmtuners.com/forums/cyl...ook-4g63-pcv-system-engine-internal-view.html
     
  10. LandSpeed-DSM

    LandSpeed-DSM Proven Member

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    ROFL

    I do, yes.

    So, in your opinion what is the best way to clean the casting flaws out?
    040_zps135c35cc.jpg

    I was going to run a long drill bit and then a rasp through on a block I'm prepping for when my 6-bolt rod/NPR piston motor finally succumbs to the HX52.
     

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  11. gofer

    gofer Moderator

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    Is this a good idea on motor with BS's still installed?

    Can this be done with the engine assembled?

    I think I know the answers to both of these, just a good idea to teach to the lowest common denominator so people aren't getting metal shavings in their oil pan. :)

    :dsm:
     

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  12. BogusSVO

    BogusSVO Proven Member

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    Gofer, with the spot I chose, It will not matter if the balance shafts are installed or not. This is due to the fact it is not in a BS tunnel.
     
  13. BogusSVO

    BogusSVO Proven Member

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    Oh I am tinkering with oil drain back, it is nothing new, just carried over from when I built small blocks.

    A 302 on the stand
    IMG_2821.jpg

    So I carried it over to a 4g block
    IMG_2818.jpg

    While I was at it, I did a few..
    IMG_2820.jpg


    In this location, from me? None.

    I use a die grinder and a long burr
     
  14. TeamFury

    TeamFury Proven Member

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    Do you plan on running an inline check valve with this set-up back to the intake or intake manifold. Or just run it to an atmosperic catch can?
     

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  15. 1qkfwd

    1qkfwd DSM Wiseman

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    Im sure that's better than spending hours smoothing the inner block walls with a grinder ROFL

    Most the problems I have seen are in the head. The casting is crap with the amount of flash that they left behind.
     

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  16. arrowhead

    arrowhead Proven Member

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    Is that good all GLYPTAL you are using to paint?

    This was very popular with engine builders back in the 60s an 70s, not only helps with oil drainback but it also seals dust and particles when the engine or head has been machine.

    The practice fell out of favor in the 80s since some builders claimed the paint was coming off, of course it has probably been improved since then.

    I always used it and never have had any problems.
     

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  17. 1qkfwd

    1qkfwd DSM Wiseman

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    Im sure its like any paint procedure, prep is everything.
     

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  18. BogusSVO

    BogusSVO Proven Member

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    I got you to outside the block, How you choose to put it to use will be your decision.

    I saw where there was some debate on how to vent the block, so this is my .02 cents on the subject.


    Yeah the head has a good amount of flashing that needs to be dealt with, even in the most stock builds.

    About the same stuff, I have been using it for years, I have not had an issue with it. Even after it has been through a oven, then hit with an airless shot blaster.

    Yes, that is true. The block has to be sooooo clean to get this stuff to stick and stay there. any amount of oil mist under it and it will flake off.
     
  19. bastarddsm

    bastarddsm Proven Member

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    User MarkL has a similar setup to this. He says he gets about a pint of oil in the catch can after a pass.
     

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  20. Kapok6

    Kapok6 Proven Member

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    Bogus, instead of using this as a vent, what if you installed the other end of this vent to a vacuum pump?

    Thoughts?
     
    Kapok6

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  21. YoYo_4G63

    YoYo_4G63 Proven Member

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    Amazing! where the hose fitting goes connected to? catchcan?
     
  22. turbotalon1g

    turbotalon1g Proven Member

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    Mark L has a -16 from the head, not even close to the same setup.
     

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  23. LandSpeed-DSM

    LandSpeed-DSM Proven Member

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    If it's what I think you are referring to.. the -16 is an external oil return, not explicitly part of his PCV in the way this sort of block vent is.
     

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  24. bastarddsm

    bastarddsm Proven Member

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    it is a -16 in the head. However it goes right to the same set of drain-backs, and if you look closely, that's not even a drain-back in the head, it's just a crankcase vent. It's the same thing son.
     

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  25. LandSpeed-DSM

    LandSpeed-DSM Proven Member

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    Which brings me back to one of my earlier thoughts.. so with this external drain we've increased the total cross section allowing oil to drain back, but this has also made it easier for all that blow-by to fight the falling oil to try and escape the crank case to the VC vents.

    Having a divorced crank vent like this one that Dale has installed, even one that goes to a can that also connects to the VC vents, would be better than just VC vents. Additional external oil return or not.
     

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