Rochester carburetors

Discussion in '1947-1954' started by LaTroca52, Jun 6, 2020.

  1. LaTroca52

    LaTroca52 Member

    Joined:
    Feb 18, 2007
    Messages:
    815
    I have 2 Rochester carburetors both have been rebuilt sometime back one is on the truck now and works great btw 235 engine
    Do I have to do anything different in order to put both of them on a Fenton duel intake manifold?
    Will I notice any improvement in performance with duel carbs ?
    I have Fenton headers and a pertronix ignition that will be installed before end of this summer.
    Thanks for any feedback
     
  2. RidesWithYah

    RidesWithYah Member

    Joined:
    Jan 10, 2011
    Messages:
    280
    Location:
    Lexington KY
    I haven't done this yet but looked into it... From what I've read, a pair of 235 carbs end up "too big". Folks recommend a pair of 216 carbs; or Tom Langdon sells a small carb that's supposed to be great for this type of setup. Whatever you decide, make sure they are jetted *exactly* alike. And I hear choke is only needed on one.
    Store - Langdon's Stovebolt
     
  3. LaTroca52

    LaTroca52 Member

    Joined:
    Feb 18, 2007
    Messages:
    815
    I do believe they are jetted the same only difference I had seen in them was when one was on the 216 engine was the base of the carburetor when I swapped to the 235 I just changed the carburetor base for a 235 base.
     
  4. LaTroca52

    LaTroca52 Member

    Joined:
    Feb 18, 2007
    Messages:
    815
  5. LaTroca52

    LaTroca52 Member

    Joined:
    Feb 18, 2007
    Messages:
    815
    Are these the only two gaskets needed for a Fenton duel carburetor intake manifold?
    Thick insulator on manifold and thin gasket between carburetor and thick insulator?
     
  6. LaTroca52

    LaTroca52 Member

    Joined:
    Feb 18, 2007
    Messages:
    815
    I’m looking for a 1 barrel Rochester carburetor base for a 235 engine
    If anyone has a core carb please let me know.
    Thanks
     
  7. vwnate1

    vwnate1 Member

    Joined:
    Jan 1, 2000
    Messages:
    11,154
    Location:
    AMERICA !
    Lotta disinformation on dual carbys .

    You need two identically jettedcarbys, 'B' series Rochesters are fine .

    You'll need to balance them, this is the tricky part ~ be sure to have a separate return spring on each one, the spring must be very gentle ~ no big beefy thing .

    Disconnect the linkage between the two carbys and warm up the engine then use a uni - syn device or other manometer to get both carbys to pull the *excact* same vacuum at idle then adjust the idle speed to 500 ~ 1,000 RPM then re attach the linkage .

    Of course, you'll need to begin by ensuring the valves are bang spot on and the ignition timing is perfectly set to ball on pointer or you'll be chasing your tail forever .

    Don't be shy to ask for help repeatedly ~ those who know this can do it fairly easily .

    I used to do it by ear before my hearing went .

    Yes, more power, and better idle along with better fuel economy *if* you can resist using all that extra power....
     

Share This Page