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GVR-4 Drilling 2g head / oil mod

Posted by LumpyVR4, Apr 15, 2019

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  1. LumpyVR4

    LumpyVR4 Supporting Member

    24
    11
    Joined May 21, 2014
    Sydney, Australia
    Getting a 2g head CNC'ed for my new build. I was wondering if, while I'm getting the bolt holes taken out to 1/2 inch, whether it would be worth getting the shop to drill the oil hole out to 13mm to the depth of the oil feed, to give the head as much oil as it wants. I'm not worried about bypass oil ending up in the head as I'm fitting a Kiggly regulator. Thoughts?
     

    Street Build 361  6

    1990 Mitsubishi Galant VR-4
    manual · Galant VR-4

    Street Build 2K  0

    1992 Mitsubishi Galant VR-4
    manual · Galant VR-4
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  2. ec17pse

    ec17pse Freelancer

    3,423
    1,316
    Joined Nov 1, 2008
    London, Europe
    I believe the issue is drain of oil not oil feed, so going bigger might allow more oil to drain but the amount wont be alot more, the newer 4G63 engines have more oil drains then we got so concentrate on oil return rather then getting oil to the head ok
     

    Road Race Build 8K  10  50

    1997 Mitsubishi Eclipse GST
    175 whp · 180.1 lb/ft · 2G DSM
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  3. 007jimmy

    007jimmy Proven Member

    1,467
    96
    Joined Feb 27, 2012
    Levittown, Pennsylvania
    I have done this on my 1g 7 bolt head. I ported the teardrop to .120” tapering deeper to the stud hole along with undercutting the 6 bolt ARP stud. I was looking for max oil flow along with lowering the block oil pressure. (I have no squirters/BS.) Valvetrain is nice and quiet. Just make sure you clear the casting flash in all of the return holes. I have the kiggly unit as well. About 5k miles on this build so far and no issues
     

    Street Build 885  25

    1997 Mitsubishi Eclipse GSX
    awd · automatic · 2G DSM
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  4. LumpyVR4

    LumpyVR4 Supporting Member

    24
    11
    Joined May 21, 2014
    Sydney, Australia
    Definitely cleaning up flash to make it drain fast. Once lost the big ends on a 351 Cleveland due to all the oil being in the heads. Here is one of the drain holes when I pulled the head on the weekend.
     

    Attached Files:

    Street Build 361  6

    1990 Mitsubishi Galant VR-4
    manual · Galant VR-4

    Street Build 2K  0

    1992 Mitsubishi Galant VR-4
    manual · Galant VR-4
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  5. 1990TSIAWDTALON

    1990TSIAWDTALON Moderator

    4,417
    1,904
    Joined Nov 14, 2013
    Independence, Kansas
    I always painted my SBC oil galleys which helped oil return to the pan faster that it would on bare cast. Never had any flaking or problems. When I would tear one down, it was still orange inside like the day I painted it. Worked on those V motors good for oil return.
     

    Street Build 3K  27

    1992 Eagle Talon TSi AWD
    awd · automatic · 1G DSM

    428  14

    1990 Mitsubishi Eclipse GSX
    awd · manual · 1G DSM

    417  17

    1967 Chevrolet Camaro RS
    rwd · automatic · Misc Vehicles

    Street Build 605  4

    1998 Eagle Talon TSi
    fwd · manual · 2G DSM

    Street Build 5K  11  25

    1990 Eagle Talon TSi AWD
    13.620 @ 108.460 · 1G DSM
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