Volvo RWD 120-130 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 5/2001 120-130 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

SU dimensions? 120-130

posted by  Bones 122 on  Wed May 15 06:08 CST 2013
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Wed Dec 4 10:39 CST 2013
[RELATED]

....so playing with my SU's Im finally getting 'it' in terms of how they work and they are working quite nicely at this point. My question is related to the dimension of 1 3/4" I see often when people discuss the SU's. I surmise this to be the bore of the intake and wonder what other sizes are there and how do we determine what we have? I measured my bore where the filter mounts too and it measures closer to 1 5/8" than it does 1 3/4" which is why Im asking this question.
Im also using KN needles, not knowing much about needle sizing pertaining to CI on the motor Im curious what you guys think the proper needle for a B20 is.








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    SU dimensions? 120-130

    posted by  Volvo From Heck on  Wed May 15 08:07 CST 2013
    Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
    last visit: Mon Oct 13 20:56 CST 2014
    [RELATED]

    The 1 and 3/4 measurement refers to the throttle diameter. There are SU carbs made for smaller engines--I think 1 and 1/4 inch (MG Midgets, AH Sprites) and 2 inch for larger engines (Jaguar, Rolls Royce) and bigger still I think on classic 1930's cars, but not positive.
    Regarding the question about the KN needles--if your car is in proper tune--how does it perform for you? Driveability?, gas mileage? etc. If you have reservations about the performance maybe there's something to be gained by experimenting with other needles. -- Dave








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      SU dimensions? 120-130

      posted by  Bones 122 on  Wed May 15 10:24 CST 2013
      Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
      last visit: Wed Dec 4 10:39 CST 2013
      [RELATED]

      The car performs fine, Im enjoying it considerably. I definitely have the 1 3/4 carbs. Ill look into the different size needles, Im sure the KN's are fine for me but am curious to see what differences there might be in others, thanks.








      •   REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

        SU dimensions? 120-130

        posted by  walrus3 on  Thu May 16 16:15 CST 2013
        Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
        last visit: Mon Dec 2 14:20 CST 2013
        [RELATED]

        I imagine others will suggest their favorite needles.
        The fact that the carb is identified as an HS6 means that the main barrel is 1 3/4". There are HD8s at 2", HD4s at 1 1/2", etc.
        Now: Some of the HS6 carbs mounted the air cleaner with 2 bolts and an adapter for the
        PCV hose, while others used 3 bolts and the front filter had the hose adaptor built
        into it. I believe the 3-bolt filter mount carbs have a little bigger intake barrel
        than the 2-bolt versions and thus MIGHT be able to give a little more power.
        If I were going "all out" that is what I would want to do. But I think the
        difference, IF ANY, is pretty small,
        --
        George Downs Bartlesville, Oklahoma








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    SU dimensions? 120-130

    posted by  Phil S. on  Wed May 15 07:58 CST 2013
    Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
    last visit: Fri Oct 24 13:18 CST 2014
    [RELATED]

    The size is the diameter of the throttle butterfly.








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      SU dimensions? 120-130

      posted by  gert 444 on  Thu May 16 03:26 CST 2013
      Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
      last visit: Wed Oct 22 04:11 CST 2014
      [RELATED]

      The KN needles are for use with a standard unmodified B20 engine.
      As I understood from your other posts, your engine is considerably modified.
      If you don't have problems re driveability while still using the KN needles, I think that's just luck. But you can be sure that they are not the ideal needles anymore for a correct mixture under all circumstances. Finding the best needle can only be established at a rolling road, which I would strongly advise if you want your engine to have a long life.







<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.