Page 1 of 2 12 LastLast
Results 1 to 15 of 23

Thread: Carby Tuning 18rc

  1. #1
    Junior Member Grease Monkey toylica's Avatar
    Join Date
    Oct 2008
    Location
    QLD
    Posts
    70

    Default Carby Tuning 18rc

    Hello Guys...

    This isn't a really .... 100% answerable or mechanical question....

    I have a 18rc.... i know i know... And i have looked around at many different sources... and they all seem to contradict.... anyway.... I have been told & know that my Lica' is running rich...... but How do i learn how to tune my carby? ... I have already had some experience with engines & carbys and have researched the mechanics.... but still i have no idea where to start?

    I don't know if anyone could type out a step by step general guide?... with just general needle names.... (i have had a look at the thread on here about them but mine.... you guessed it... are different ....)

    thanks in advance..


    Dave

  2. #2
    Hopefully soon a 5S-GTE Chief Engine Builder MWP's Avatar
    Join Date
    Dec 2005
    Location
    South Australia
    Posts
    4,565

    Default Re: Carby Tuning 18rc

    You cant. The main jet isnt adjustable from memory.

    You can only set the idle speed and the idle jet.

  3. #3
    Junior Member Backyard Mechanic maurice c's Avatar
    Join Date
    Feb 2006
    Location
    Yes we Canberra
    Posts
    208

    Default Re: Carby Tuning 18rc

    is it still the original carby, i think that its an aisin POS.
    Getting your missus to help bleed the brakes isn't everybody's idea of quality time.

  4. #4
    Backyard Engineer Domestic Engineer airfireman1's Avatar
    Join Date
    Apr 2006
    Location
    WA
    Posts
    749

    Default Re: Carby Tuning 18rc

    Best you can do is go and buy a carby overhaul kit, make sure it is the one to suit your carby as there are a couple of types. strip the carby down and replace all the parts with the new ones that come in the kit.
    The main reasons for it running rich are 1- high float level, 2- worn main jet,3-secondary throat opening too early.
    The kit will come with a diagram and tell you the float level you need to set.
    Cheers Dave
    Cheers Dave


    1977 RA28
    1972 TA22
    1984 Supra

  5. #5
    Junior Member Grease Monkey toylica's Avatar
    Join Date
    Oct 2008
    Location
    QLD
    Posts
    70

    Default Re: Carby Tuning 18rc

    ook - thanks. Yeh secondry isn't even working lol ... Float is about ... 2mil from the top... does look a bit high really,,,,,

    Ill have a look around.


    Thanks


    Dave

  6. #6
    Junior Member Grease Monkey toylica's Avatar
    Join Date
    Oct 2008
    Location
    QLD
    Posts
    70

    Default Re: Carby Tuning 18rc

    Quote Originally Posted by maurice c
    is it still the original carby, i think that its an aisin POS.
    Yep.... that be the one....

    my friend has a weber hes not using..... *Shifty Eyes*

  7. #7
    Junior Member Too Much Toyota
    Join Date
    Sep 2005
    Location
    Qld
    Posts
    5,590

    Default Re: Carby Tuning 18rc

    replace it with a 2bbl webber from a TC or similar 2 litre Cortina - try to do this cheaply or for no money as spending money on an 18RC is a pointless exercise.
    ------------------------------
    ST185 road barge / MZ11 forest barge / RA65 garage barge

  8. #8
    Hopefully soon a 5S-GTE Chief Engine Builder MWP's Avatar
    Join Date
    Dec 2005
    Location
    South Australia
    Posts
    4,565

    Default Re: Carby Tuning 18rc

    Quote Originally Posted by thechuckster
    replace it with a 2bbl webber from a TC or similar 2 litre Cortina - try to do this cheaply or for no money as spending money on an 18RC is a pointless exercise.
    Not true.

    I installed a Webber 34ADM on my 18R-C. It brought new life to the engine.
    For ~$50, it was the best $$s i ever spent on the car.

  9. #9
    Been there.. Done That Backyard Mechanic Cob604's Avatar
    Join Date
    Aug 2007
    Location
    NSW
    Posts
    246

    Default Re: Carby Tuning 18rc

    Quote Originally Posted by toylica
    ook - thanks. Yeh secondry isn't even working lol
    Dave
    how did u test this theory?

    thx
    Quote Originally Posted by roadkill
    When you get reaction like that it makes it all worthwhile.
    Bat mobil + 4age.. Engine painted, Fitting up now. Not long...
    Live life on the edge.

  10. #10
    Junior Member Grease Monkey toylica's Avatar
    Join Date
    Oct 2008
    Location
    QLD
    Posts
    70

    Default Re: Carby Tuning 18rc

    Quote Originally Posted by Cob604
    how did u test this theory?

    thx
    well.... i guess you know something i dont.


    the throat isn't wet.....someone said that the diaphragm dies.....?

    thnx

  11. #11
    Junior Member Grease Monkey toylica's Avatar
    Join Date
    Oct 2008
    Location
    QLD
    Posts
    70

    Default Re: Carby Tuning 18rc

    Quote Originally Posted by MWP
    Not true.

    I installed a Webber 34ADM on my 18R-C. It brought new life to the engine.
    For ~$50, it was the best $$s i ever spent on the car.
    wow... are they that cheap? where from? or just.... snipe one on ebay?


    thnx


    dave

  12. #12
    Been there.. Done That Backyard Mechanic Cob604's Avatar
    Join Date
    Aug 2007
    Location
    NSW
    Posts
    246

    Default Re: Carby Tuning 18rc

    hey

    i had mine die a few weeks ago, the diaphragm opens it therefor u wont see it open if u push the throttle, it only opens under load. so i put a new one on & just cruising down a road if u push ur foot to the floor at a point the intake noise gets deeper & madder

    with car off when i opened the secondaries by hand i could hear the air coming out of the diaphragm

    just from memory

    thx
    Quote Originally Posted by roadkill
    When you get reaction like that it makes it all worthwhile.
    Bat mobil + 4age.. Engine painted, Fitting up now. Not long...
    Live life on the edge.

  13. #13
    Hopefully soon a 5S-GTE Chief Engine Builder MWP's Avatar
    Join Date
    Dec 2005
    Location
    South Australia
    Posts
    4,565

    Default Re: Carby Tuning 18rc

    It was from a u-pull-it off a Falcon XE/XF.
    The 34ADM isnt the ideal carb (it is too large) so it took a decent amount of work to get it tuned properly.

    Quote Originally Posted by toylica
    the throat isn't wet.....someone said that the diaphragm dies.....?
    Yup, they do.
    I fixed this on my original 18R carb which made a huge difference.
    I fixed it by using a simple wire link to make the second butterfly open after ~75% throttle (bypassing the diaphragm).

    Its still worth looking at a Weber carb anyway, the 34ADM made a big difference even after the original carb fix.

  14. #14
    Junior Member Grease Monkey toylica's Avatar
    Join Date
    Oct 2008
    Location
    QLD
    Posts
    70

    Default Re: Carby Tuning 18rc

    Quote Originally Posted by MWP
    I fixed it by using a simple wire link to make the second butterfly open after ~75% throttle (bypassing the diaphragm).
    Interesting.... so if i wanted to test the diaphragm.... how would i go about it.... and... is it just the diaphragm that is nearest the front of the car...?

    When i got flat to the floor i do hear the deeper sound and such (especially with the modded intake)

    thanks


    dave

  15. #15
    Hopefully soon a 5S-GTE Chief Engine Builder MWP's Avatar
    Join Date
    Dec 2005
    Location
    South Australia
    Posts
    4,565

    Default Re: Carby Tuning 18rc

    You cant test it without pulling it apart.

    Its diaphragm actuated to stop it from opening at too low a RPM which could then stall the engine.
    If your hearing that deep sound throughout the rev range at full accel, then thats not it.
    If it is working, you should hear the note change or get louder at some point through the rev range.

Similar Threads

  1. Carby Center Stud - 18rc
    By toylica in forum Tech and Conversions
    Replies: 4
    Last Post: 05-12-2008, 06:29 PM
  2. 18rc carby rebuild
    By Big rob in forum Tech and Conversions
    Replies: 7
    Last Post: 02-03-2008, 08:16 PM
  3. 18rc carby issue
    By Hash_ra23 in forum Tech and Conversions
    Replies: 46
    Last Post: 09-05-2007, 09:28 AM
  4. 18RGU Carby and Cam Questions (long winded and a few pics)
    By floppy in forum Tech and Conversions
    Replies: 21
    Last Post: 07-01-2007, 12:25 AM

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
  •