Results 1 to 14 of 14

Thread: bigport vs smallport identifcation

  1. #1
    Forum Member 1st year Apprentice
    Join Date
    Apr 2006
    Location
    vic
    Posts
    29

    Default bigport vs smallport identifcation

    im new to the 4age game and have purchased a 4agte setup
    i would like to find out what exactly i have and the model/year if possible
    it is aparnelty based on a 4agze
    it has a cas running 4 coil packs with a microtech so no factory afm or map sensor
    the problem is it has a custom plenum and the head has (apparently) been ported
    the exhaust ports are round and smallish looking,not sure about the intake thou by goin off the runners they are larger than exhausts and kinda oval
    thanks for any help!
    Ryan

  2. #2
    back into it Chief Engine Builder
    Join Date
    Mar 2006
    Location
    nsw
    Posts
    3,991

    Default Re: bigport vs smallport identifcation

    one has bigports and the other dosnt! lol

    without the airflow meter on the bigport gze's or the factory 8 runner inlet manifold the best way is to look at the ports! bigport has 65mm wide ports and no oil return to the block unless it has been tapped in like i did. lol then the easy way is the oil return which comes out from the head on the left side of the engine{looking at the engine from the timing belt end} at the rear of the head.

  3. #3
    AVGAS DRINKING Carport Converter 30psi 4agte's Avatar
    Join Date
    Feb 2006
    Location
    S.A
    Posts
    1,457

    Default Re: bigport vs smallport identifcation

    What colour is the writing on the cam covers?



    off subject slightly but mick did you tap the big port head for the oil return?

  4. #4
    back into it Chief Engine Builder
    Join Date
    Mar 2006
    Location
    nsw
    Posts
    3,991

    Default Re: bigport vs smallport identifcation

    yes tapped to take the small port fitting, but i use braided so have a alloy one in there. there is just the right amount of meat to tap it.

  5. #5
    back into it Chief Engine Builder
    Join Date
    Mar 2006
    Location
    nsw
    Posts
    3,991

    Default Re: bigport vs smallport identifcation

    there you go!


  6. #6
    Forum Member 1st year Apprentice
    Join Date
    Apr 2006
    Location
    vic
    Posts
    29

    Default Re: bigport vs smallport identifcation

    ok from that i take it it is a smallport,it has an oil return to the block
    the cam cover has been polished so no help there
    i guess to prove weather it has been ported i can measure the ports,do people normally port the smallport out to the bigport runner size or only play with the shape and radius
    thanks for your help
    Ryan

  7. #7
    back into it Chief Engine Builder
    Join Date
    Mar 2006
    Location
    nsw
    Posts
    3,991

    Default Re: bigport vs smallport identifcation

    soon tell if its been touched in the ports without measuring! it will be shiney and smooth were a stock one is like the outside of the head, smooth but not polished smooth

  8. #8
    AVGAS DRINKING Carport Converter 30psi 4agte's Avatar
    Join Date
    Feb 2006
    Location
    S.A
    Posts
    1,457

    Default Re: bigport vs smallport identifcation

    cant quite make it out but have you blocked that coolant gallery off completely??????

  9. #9
    back into it Chief Engine Builder
    Join Date
    Mar 2006
    Location
    nsw
    Posts
    3,991

    Default Re: bigport vs smallport identifcation

    no, not at all! you can see the weldon and plug hanging on the front of the engine. need the oil return.

  10. #10
    AVGAS DRINKING Carport Converter 30psi 4agte's Avatar
    Join Date
    Feb 2006
    Location
    S.A
    Posts
    1,457

    Default Re: bigport vs smallport identifcation

    ah im talking about the plate on the back of the head.

  11. #11
    :( Backyard Mechanic stahlz_ae86's Avatar
    Join Date
    Feb 2006
    Location
    Victoria
    Posts
    274

    Default Re: bigport vs smallport identifcation

    http://www.billzilla.org/4agstock.htm

    Have a solid look through this website. I learnt heaps in doing so.

  12. #12
    back into it Chief Engine Builder
    Join Date
    Mar 2006
    Location
    nsw
    Posts
    3,991

    Default Re: bigport vs smallport identifcation

    Quote Originally Posted by 30psi 4agte
    ah im talking about the plate on the back of the head.
    yes blocked off but it has a sensor to go in and a bleed.

  13. #13
    MR 18RG Chief Engine Builder The Witzl's Avatar
    Join Date
    Jul 2005
    Location
    NSW
    Posts
    3,164

    Default Re: bigport vs smallport identifcation

    Quote Originally Posted by kingmick
    yes blocked off but it has a sensor to go in and a bleed.
    That outlet only feeds the heater anyway, so no massive drama if you blocked it off i wouldve thought?
    ...... butt scratcher?!


  14. #14
    :( Backyard Mechanic stahlz_ae86's Avatar
    Join Date
    Feb 2006
    Location
    Victoria
    Posts
    274

    Default Re: bigport vs smallport identifcation

    Quote Originally Posted by bigstickerperformance
    ok from that i take it it is a smallport,it has an oil return to the block
    the cam cover has been polished so no help there
    i guess to prove weather it has been ported i can measure the ports,do people normally port the smallport out to the bigport runner size or only play with the shape and radius
    thanks for your help
    Ryan
    Missed this question earlier, but from what I remember reading the optimum port size is somewhere between small and bigport sizes. As smallport is considered too small and bigport too big. So I guess people do increase the port size of the smallport heads, not sure how though.

    But check out the above mentioned site

Similar Threads

  1. Smallport head on bigport block(3 Rib)
    By Cuzzo in forum Tech and Conversions
    Replies: 5
    Last Post: 27-03-2006, 04:23 PM
  2. SmallPort vs Bigport HEAD 4AGZ/TE power figures
    By nick.parker in forum Tech and Conversions
    Replies: 27
    Last Post: 18-02-2006, 01:15 PM
  3. bigport smallport. What are the differences?
    By benjamin in forum Tech and Conversions
    Replies: 4
    Last Post: 06-02-2006, 11:17 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •