FYI FORD - MustangSteve's Ford Mustang Forum
The Internet's Most Knowledgeable Classic Mustang Information
IF YOU HAVE A QUESTION ABOUT CLASSIC FORD MUSTANGS, YOU HAVE COME TO THE RIGHT PLACE!
MustangSteve has over 30 years of Mustang experience, having owned 30 of them and restored several others. With the help of other Mustangers, this site is dedicated to helping anyone wanting to restore or modify their Mustang.... THERE ARE NO DUMB QUESTIONS!!!!!
Visit MustangSteve's web site to view some of my work and find details for:
FYIFORD Contributors' PICTURES - Power Brake Retrofit Kits for 65-66 Stangs - Classic Mustang FAQ's by MustangSteve - How to wire in a Duraspark Ignition - Mustang Ride Height Pictures and Descriptions - Steel Bushings to fit Granada Spindles to Mustang Tie Rods - Visit my EBAY store MustangSteve Performance - How to Install Granada Disc Brakes MustangSteve's Disc Brake Swap Page - FYIFORD Acronyms for guide to all the acronyms used on this page - FYIFORD Important information and upcoming events

You are not logged in. Would you like to login or register?

  • Index
  •  » FYI Ford, Classic Mustang Tech Discussion
  •  » Autolite 4100 Carb.

    • 1 of 1

       

    5/15/2014 4:43 PM  #1

    wsinsle
    Senior 24-7 FYI Addict

    Offline

    From: Belle Vernon, PA
    Registered: 4/01/2013
    Posts: 1,664

    Autolite 4100 Carb.

        First a little back ground. I bought a 1.08 4100 autolite carb to put on my lightly beefed up 289. I asked a question on here about it and Boom pointed out not all 1.08's are created equal. Did a little research and this is what I found, Remember this is from the internet not a Ford Bible. Some places stated some big block 1.08's were different than small block 1.08's. One place stated some 1.08 had 4 1.44" bores. Some had 1.44 primary bore and 1.56" secondary bore. The 1.12 Carb had 4 - 1.56 bores, with 1.12 primary venturies and 1.18 secondary venturies. Although all 1.08 carbs have 1.08 primary venturies, there was not really any info stating differences in secondary venturies between big and small block carbs. (Are we confused yet) One other thing, they stated the Mustang 289 HIPO used a 1.12 4100 with (I think) 58 primary jets and 67 secondary jets.
         Now this is what I have and can state as fact. Ford autolite 4100 1.08 carb. All 4 bores are 1.44". The primary venturies are 1.08" and the secondarys are 1.18". This was from a big block Ford. The primary jets are 48 and the secondarys are 67. Boomyal I'm curious as to how this compaires to the small block 1.08's you have. Any how I rebuilt this with a kit from Mikes Carb, nice guy, and put it on my 289. Turned the adjustment screws out 1&3/8 turns, started the car and it runs great under no load in the garage. Part of this was to get feed back from others on this carb.
         NOW THE QUESTIONS
         How do I fine tune the Air / Fuel mixture screws? Are these the correct jet sizes I should be using? Any thought on this would be greatly appricated. I now offically know more about carburetors than women, but that is still very little.
     

    If this forum can't fix it, it isn't broke.
     

    5/15/2014 5:24 PM  #2

    boomyal
    Senior 24-7 FYI Addict

    Offline

    From: Vancouver, Washington
    Registered: 4/01/2013
    Posts: 1,295

    Re: Autolite 4100 Carb.

    The 65 and 66 automatics had 48 primary jets and 58 secondary jets.  Another critical part is the boosters.  It is easy enough to find which boosters were intended for a specific application but Autolite never posted any kind of listing as to the values of those boosters numbers. As these parts are no longer available, this keeps you from choosing the next best booster if you do not have the correct ones. The 65/6 Mustang used CH boosters for the primaries and A boosters for the secondaries.  Wrong boosters, for a particular motor, can cause issues.

    Also, from all I can gather, there are ports and orifices in the main body of the carb that cannot be altered.  This is one of the reasons that 1.08 big block carbs have not done well on SB motors.

    What is the number stamped into the foot of your carb?

    Also, for what ever good it will do, what are your booster numbers/letters?

    Last edited by boomyal (5/15/2014 5:33 PM)

     

    5/15/2014 8:15 PM  #3

    ponch0v
    FYI Addict

    Offline

    From: Coeur d'Alene, ID
    Registered: 4/01/2013
    Posts: 140

    Re: Autolite 4100 Carb.

    tons of Ford/Autolite carb info here:

    http://www.network54.com/Forum/88781/

     

    5/16/2014 9:24 AM  #4

    wsinsle
    Senior 24-7 FYI Addict

    Offline

    From: Belle Vernon, PA
    Registered: 4/01/2013
    Posts: 1,664

    Re: Autolite 4100 Carb.

    Ponch, sure is alot! Boom, never thought to look, I'll check this afternoon.

    If this forum can't fix it, it isn't broke.
       •Thread Starter
     

    5/21/2014 4:07 PM  #5

    wsinsle
    Senior 24-7 FYI Addict

    Offline

    From: Belle Vernon, PA
    Registered: 4/01/2013
    Posts: 1,664

    Re: Autolite 4100 Carb.

    Boom soory I didn't reply sooner. Primary boosters 2D      Secondary boosters F
                                                     Primary Jets       48       Secondary Jets       67

    Carb Base 6A F
    Tag C6AF F

    I know it is from a big block. Right now it's on the car (lightly built 289) and seems to run good. But this is in the garage under no load. I think my plan is wait till it's on the road and see how it runs. Maybe jet down the secondaries a little if needed. If it don't run good then I'll be looking. Thanks for any more infoor or thoughts.

    If this forum can't fix it, it isn't broke.
       •Thread Starter
     

    5/21/2014 6:18 PM  #6

    boomyal
    Senior 24-7 FYI Addict

    Offline

    From: Vancouver, Washington
    Registered: 4/01/2013
    Posts: 1,295

    Re: Autolite 4100 Carb.

    wsinsle wrote:

    Boom soory I didn't reply sooner. Primary boosters 2D      Secondary boosters F
                                                     Primary Jets       48       Secondary Jets       67

    Carb Base 6A F
    Tag C6AF F

    I know it is from a big block. Right now it's on the car (lightly built 289) and seems to run good. But this is in the garage under no load. I think my plan is wait till it's on the road and see how it runs. Maybe jet down the secondaries a little if needed. If it don't run good then I'll be looking. Thanks for any more infoor or thoughts.

    At least it does not appear to be a California Emissions Big Block Carb.  Those are even more problematic on SBFs.  Here is a good case where it would be nice to know the values of the boosters.  As I mentioned, Autolite never made a list and the designations seem to be totally random. Some of them are double letters, some a number and a letter and others a single letter.  If they had numbered them 1 thru say 15, it would be a lot easier to pick boosters that were close to the originals if you could not find the exact ones..

    My '65 manual tells me the proper boosters for my year, but they do not specify any values.  Jet numbers are their values so that is easy and yes, 67 secondaries will wash your cylinder walls if not make the car run crappy when they are triggered.
     

    Last edited by boomyal (5/21/2014 6:23 PM)

     

     

    1 of 1

  • Index
  •  » FYI Ford, Classic Mustang Tech Discussion
  •  »  Autolite 4100 Carb.

    • Board footera


    REMEMBER!!! When posting a question about your Mustang or other Ford on this forum, BE SURE to tell us what it is, what year, engine, etc so we have enough information to go on.