1. Join the Community!

    DSMtuners is a massive archive of DSM information - but more importantly, it's a COMMUNITY! Join in and participate with other DSMers, and invite all of your DSM friends to make this place their home. Chat with others, create a build thread, post questions and answers. Get involved! Logging in will also remove many of the advertisements, along with this notice. ;)

1g head vs 2g head

Posted by turbo tim1, Jan 25, 2011

Please Support Morrison Fabrications
Please Support Fuel Injector Clinic
  1. turbo tim1

    turbo tim1 Proven Member

    145
    1
    Joined Sep 16, 2010
    blackfalds, AB, Canada
    I have read that the 2g cylinder head flows more air than the 1g head despite the larger ports of the 1g head.

    If both heads were ported which one would flow more.

    I have a mix of dsm parts, enough to throw an engine together so I was thinking of building a project Frankenstein, a 4g64 block with 2g pistons 1g rods and possibly a 2g ported head, depending on which head flows more.:hellyeah:
     

    234  0

    1992 Eagle Talon TSi AWD
    · 1G DSM
    Loading...

    Featured Products from our Supporting Vendors

  2. DSMReviver

    DSMReviver Proven Member

    810
    75
    Joined Mar 4, 2008
    Little Rock, Arkansas
    2g will flow better in stock/small turbos. If you are upgrading to bigger turbos, 1g big ports are suitable.

    If both heads are ported i would still take the 1g head. 1g heads are already design that way to take in more air volume for bigger turbos and the angle geometry is already calculated with the increase port. I believe if the 2g runners are ported, they will loose their intake volume angle and will distort the flow. But im sure if you port the 2g's out, you will see a benefit of larger volume intake but only up to an extent. But both head are good for a specific needs. im running a 16g turbo right now and i would love to have a 2g head(flow velocity is amazing) but if i go bigger like gt35r/holset hx35,40/gt40r i would want 1g.
     
    DSMReviver

    1K  0

    1995 Mitsubishi Eclipse GSX
    manual · 2G DSM

    Showcar Build 809  0

    1998 Eagle Talon TSi AWD
    manual · 2G DSM
    Loading...
  3. NeMiZiS

    NeMiZiS Supporting VIP

    1,363
    22
    Joined Jul 25, 2007
    Palmer, Alaska
    From what I've read the 2g head is supposed to be a better design.
    It seems like the 1g head would flow better, looking at the picture.

    images?q=tbn:ANd9GcQcFJfLserWUXavEIuF4lSCUirb6OPgI5ezPuCsKlxC71oe2Ztd&t=1.jpg
     

    Street Build 964  3

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

    688  1

    1995 Mitsubishi Eclipse N/T
    manual · 1G DSM
    Loading...
  4. VETTE_50_TH

    VETTE_50_TH Proven Member

    1,994
    20
    Joined Jun 24, 2004
    Columbus, Ohio
    Ive read some good and some bad. I dont think anyone has ever done real testing on either one that could be used as fact. Im glad its that way, because prices of certain heads would depreciate so much that all of them would go to the junkers and one would sky rocket. But i know one thing, the 2g oiling system is ####ing retarded.
     

    701  0

    1998 Mitsubishi Eclipse GSX
    manual · 2G DSM
    Loading...
  5. LiquidX

    LiquidX DSM Wiseman

    6,607
    102
    Joined Sep 19, 2008
    Anywhere, Pennsylvania
    2g has higher velocity than the 1g. It has been discussed that the 2g head is a better overall design and has taken cars into deep numbers.

    I'm currently at an estimated 450-500hp via ECMlink v3 on an un porter 2g head with an Evo3 intake manifold so take it for what it's worth.

    The numbers are not stating what the car is really producing as it has not been dynoed.
     

    Street Build 2K  0

    1997 Eagle Talon TSi AWD
    manual · 2G DSM
    Loading...
  6. m_0ney_pit

    m_0ney_pit Proven Member

    589
    29
    Joined Jan 12, 2007
    Reading, Pennsylvania
    2g head is will flow air faster(higher flow rate) in relation to the 1g. choice will depend on your mass of air being flowed as said above. for most people the 2g is better.
     

    Street Build 414  3

    1998 Eagle Talon TSi AWD
    awd · automatic · 2G DSM

    Street Build 1K  0

    1999
    manual · 2G DSM

    Street Build 1K  0

    1999 Mitsubishi Eclipse GST
    manual · 2G DSM
    Loading...
  7. DSMunknown

    DSMunknown Proven Member

    2,950
    32
    Joined Sep 16, 2004
    Worcester, Massachusetts
    IDK why people spew sh** out when they don't know what they're talking about.



     
    303_2G likes this.
  8. Boostjunki84

    Boostjunki84 Proven Member

    353
    3
    Joined Oct 12, 2007
    Candler, North Carolina
    +1. I was just about to say the same thing. That's why you see more and more people running the 6-bolt with a 2g head.
     

    295  0

    1996 Eagle Talon TSi
    manual · 2G DSM
    Loading...
  9. spawn87

    spawn87 Proven Member

    697
    2
    Joined Dec 6, 2007
    sacramento, California
    well im not going to say the 1g head isnt good but since my car is a 2g and its a DD in california i wanted to build an engine that was "legal"

    the logical choice for bottom is the 6bolt and the 1g rods.
    for the head i went with a mild ported 2g build head with the 1g tb and 272s.

    biggest choke point is the tb and the flange on the 2g manifold. you port that and go 1g tb and that is already making up in runner size and further increasing velocity. you want more top end go with the evo3 manifold. point is i read for about 1 month almost all benefits and cons to going ether 1g or 2g head and in the end i choose 2g head. take it for what its worth but my engine feels pretty good plenty of power in mid and top range (enough to get away from those hondas and disappoint those mustang gt on the long run) and i havent even gotten the car tuned yet.

    at the end of the day it all depends what you want the engine for and what its going into.

    both 2g and 1g heads have their benefits you just have to see if the benefits suit your goal.
     

    560  0

    1995 Eagle Talon TSi AWD
    14.468 @ 101.474 · 2G DSM
    Loading...
  10. turbo tim1

    turbo tim1 Proven Member

    145
    1
    Joined Sep 16, 2010
    blackfalds, AB, Canada
    Sounds like no one has flow bench tested either head against each other, I will probly go with the 1g head because of the volume difference in port size.
     

    234  0

    1992 Eagle Talon TSi AWD
    · 1G DSM
    Loading...
  11. Kapok6

    Kapok6 Proven Member

    1,228
    253
    Joined Aug 10, 2004
    Fort Worth, Texas
    Thanks for quoting kiggly. Every Evo since the evo 3 has had small port heads. Is that because the Mitsu engineers are tards? I think not...
     
    Kapok6

    Street Build 2K  0

    1991 Mitsubishi Eclipse GSX
    11.3 @ 130.75 · 1G DSM
    Loading...
  12. daren_p

    daren_p DSM Wiseman

    4,551
    84
    Joined Nov 22, 2004
    Newmarket, ON, Canada

    Please see post #7 above, if you don't know who Kiggly is, please google/youtube the name. I'm pretty sure the "smaller" volume in the 2g head isn't an issue for most DSMers :shhh:

    Both heads work, take your pick for what best suites your application/needs.
     

    2K  18

    1998 Mitsubishi Eclipse GSX
    12.370 @ 119.800 · 2G DSM
    Loading...
  13. 1AWD90

    1AWD90 Proven Member

    127
    0
    Joined Sep 6, 2007
    Marshall, Minnesota
    I have flow bench tested stock 1g head and also again after I ported, polished and went to 1mm oversized valves. I have the numbers at home if anyone is interested in seeing them I can post them tonight. However, I have not tested a 2g head. I have always had 1g heads at my disposal so that is what I have used. I have always seen nice gains in porting a 1g head but it all depends on if you want velocity or volume.
     

    250  0

    1990 Mitsubishi Eclipse GSX
    manual · 1G DSM
    Loading...
  14. turbo tim1

    turbo tim1 Proven Member

    145
    1
    Joined Sep 16, 2010
    blackfalds, AB, Canada
    Please post the numbers I would like to see the difference in flow from stock to ported.

    Hopefully some one has done the same with a 2g head, I would like to see and compare numbers rather than basing a decision on hear says and speculation.
     

    234  0

    1992 Eagle Talon TSi AWD
    · 1G DSM
    Loading...
  15. 99gst_racer

    99gst_racer Moderator

    9,037
    755
    Joined Apr 5, 2003
    Coloma, Michigan
    The whole idea behind the design of the 2G head, is that it's a "raised port" design. This helps with air velocity, which can improve low-end HP and torque. Potential benefits include:

    * The higher the air flow speed, the better the air/fuel mixture is atomized. This improve the combustion process.
    * The higher velocity improves the combustion chamber 'swirl'. The 'swirl' distributes the air/fuel mixture in the combustion chamber, improving the combustion process.
    * The higher the velocity, the greater the inertia of the air flow. This helps fill the cylinder to its maximum, improving the VE (volumetric efficiency).

    The vantage point the incoming air has to the back of the intake valve is sometimes referred to as the angle of attack. Due to its added height, a raised-runner head simply has a better angle of attack or vantage point for a straighter shot to the back of the valve. The added height also reduces the angle of the turn that the incoming charge must negotiate. The geometry of a raised-runner port is superior to a similar nonraised runner design, since it allows additional airflow and a higher terminal velocity before it stalls or backs up.

    That depends on how it was ported. Any decent cylinder head porter will tell you that it's not a matter of just hogging the port out larger. It's performance greatly depends on where the material is removed and the overall shape of the port. Without getting into details about the port shape, the proper way to port a 2G head runner it to remove material on the ceiling of the port and leave the floor alone for the most part.
     

    Street Build 5K  67

    1999 Mitsubishi Eclipse GST
    609.8 whp · 541.2 lb/ft · 2G DSM
    Loading...
    DogWhistle likes this.
  16. 99gst_racer

    99gst_racer Moderator

    9,037
    755
    Joined Apr 5, 2003
    Coloma, Michigan
    A good friend of mine has a performance shop about an hour away. He's a DSMer and is very good with head work (he does my head work on my 2G). He's in the process of building a 1G head that has a different scenario for each bank. It ranges from stock, to mild and aggressive porting, to oversized valves and bowl work. He's going to flow bench each bank and see where and how much the improvements are. And as soon as he can locate a junk core 2G head, he's going to do the same with that. So, be on the lookout for test results to be posted here sometime this spring. :)

    Once and for all, we'll know how each compares to the other.
     

    Street Build 5K  67

    1999 Mitsubishi Eclipse GST
    609.8 whp · 541.2 lb/ft · 2G DSM
    Loading...
  17. 2slow4now

    2slow4now Proven Member

    914
    37
    Joined Nov 20, 2008
    otwell, Indiana
    If you don't have a flow bench to test what grinding/hogging out needs to be done then the best you can do is just do a mild cleaning up of the ports and port match everything. Just make clean smooth transfers for the air to follow from the intake thru the head and out the exhaust.
    So 1g or 2g head? Either cleaned up a bit will do fine. If you want anything more than smooth flow then you have to get serious. Flow bench, a test head or two to experiment on, make sheet metal templates when you get the flow numbers, lots of grinding and matching each port with the template you made. Or take it to a shop that does our heads and fork out the cash.
    +1 on 99gst racer and every body else LOL
     

    802  11

    1995 Eagle Talon TSi
    awd · manual · 2G DSM
    Loading...
  18. VETTE_50_TH

    VETTE_50_TH Proven Member

    1,994
    20
    Joined Jun 24, 2004
    Columbus, Ohio
    Ive got one if you want to pay to ship it. :thumb:
     

    701  0

    1998 Mitsubishi Eclipse GSX
    manual · 2G DSM
    Loading...
  19. knochgoon24

    knochgoon24 DSM Wiseman

    4,753
    64
    Joined Jan 29, 2008
    Troy, Michigan
    Maybe he could throw info on the Hyundai head in there too. He probably doesn't need to flow test it, but just having all the head info in one place would be nice.
     

    1K  1

    1997 Mitsubishi Eclipse Spyder GST
    fwd · manual · 2G DSM

    1K  0

    1991 Eagle Talon N/T
    manual · 1G DSM

    2K  0

    1996 Mitsubishi Eclipse GST
    automatic · 2G DSM

    2K  0

    1997 Eagle Talon TSi AWD
    13.869 @ 95.090 · 2G DSM
    Loading...
  20. turbo23

    turbo23 Proven Member

    233
    10
    Joined Oct 25, 2005
    Shelbyville, Michigan
    I accually thought i had my hands on a hyundai head, but that fell through.. Since i havent done the testing yet, I'm not sure which head will flow better.. There are tons of variables to consider with choosing a cylinder head. So much so, that covering all the bases would just lead to more questions. Like for instance:

    - Engine volume
    - Engine rpm
    - Camshaft lift
    - Camshaft duration
    - Pistons speed at crank angle and valve lift
    - Rod ratio

    All these should be considered, and much more. its all about the combo.

    For what most people are doing, I would agree that the runner volume of the 2g head is better suited..
     

    2K  0

    1993 Eagle Talon TSi AWD
    9.630 @ 145.080 · 1G DSM
    Loading...
  21. VETTE_50_TH

    VETTE_50_TH Proven Member

    1,994
    20
    Joined Jun 24, 2004
    Columbus, Ohio
    Can you tell me which i need then if i tell you all the answers to your questions?

    Also, turbo23 now has his 2g head for the flow tests.
     

    701  0

    1998 Mitsubishi Eclipse GSX
    manual · 2G DSM
    Loading...
  22. turbo23

    turbo23 Proven Member

    233
    10
    Joined Oct 25, 2005
    Shelbyville, Michigan
    If you give me stroke and bore, valve lift, cam duration @ .050 and advertised (@ .020). i'll be able to tell what target rpm is, also what intake and turbo. IMO the 2g head will be better suited for 99% of the combos i've seen.

    I'd like to do a back to back test on a 1g head and a 2g head, and look at the power band and total output differences. I still wonder how much of an affect air density has on cylinder head choices, and also back preassure as well. Like I said, its all about the combo. Just because a head flows better, doesn't mean it'll make more power.
     
    Last edited by a moderator: Jul 10, 2014

    2K  0

    1993 Eagle Talon TSi AWD
    9.630 @ 145.080 · 1G DSM
    Loading...
  23. hurricanecris24

    hurricanecris24 Proven Member

    809
    8
    Joined Jul 14, 2009
    NORCAL, California
    Just that I would throw out there that I'm getting my 2g head port match on the intake side with a aftermarket intake manifold so would my head be the same as a 1g head?
     
    hurricanecris24

    409  0

    1995 Mitsubishi Eclipse GSX
    · 2G DSM
    Loading...
  24. turbo23

    turbo23 Proven Member

    233
    10
    Joined Oct 25, 2005
    Shelbyville, Michigan
    I'm assuming its a 1g manifold, better idea would be to fill the intake to match the head.. imo anyway
     

    2K  0

    1993 Eagle Talon TSi AWD
    9.630 @ 145.080 · 1G DSM
    Loading...
  25. ramsack

    ramsack Proven Member

    2,195
    14
    Joined Dec 27, 2007
    West Lawn, Pennsylvania
    An even better idea would be to just sell that intake manifold and get the 2g version of it. Most companies that make them have 1g and 2g manifolds available.
     

Share This Page

Support Vendors who Support the DSM Community
Archer Fabrication ECM Tuning ExtremePSI Feal Suspension Fuel Injector Clinic Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications OHM Racing RockAuto SouthBay Fuel Injectors STM Tuned VR Speed Factory White Shed Speed