Results 1 to 5 of 5

Thread: Carb Bonnet

  1. #1
    Might as well be part of the furniture.
    Join Date
    Jun 2013
    Location
    welwyn
    Posts
    2,246

    Carb Bonnet

    I'm looking into maybe fitting LPG to the Vette I will need either a very thin air filter or preferably a carb bonnet that allows a remote filter to be connected to the carb, the sort of thing that you would probably use if turboing a carb'd engine. Prefer aluminium but plastic would work I think.

  2. #2
    Carburetion 'sucks' !
    Join Date
    Jun 2013
    Location
    Driving 'round the M25 so fast the centrifugal force is forcing my face against the side window!
    Posts
    719
    To get more clearance under the hood, replace the drop down OEM filter base with a shallower unit.


    Replace the OEM 2.5" filter with a thinner element (1.5", 1.750")



    Use a K & N filter 'top'


    The stock GM drop down filter base will prevent the use of thin filter elements and destroy internal air flow to carb.
    Last edited by roscobbc; 01-06-21 at 01:57 AM.

  3. #3
    Might as well be part of the furniture.
    Join Date
    Jun 2013
    Location
    welwyn
    Posts
    2,246
    I already have an after market dropped air filter base, it's just over 1.5" drop but the filter element is 3" plus the aluminium top is 1/2" thick.

    I have been having a look today and the mixer needs to sit directly on top of the carb with the filter base on that, however, I now don't know what engine this was fitted to as the mixer is unable to fit flush on the Quadrajet due to the choke and the vent pipe. With this in mind I thought I would look at the old Holley again but the same case, the mixer can't fit flush unless I remove the Choke flaf and remove the choke horn.

    I'm tempted to cut the Holley up and get a better rebuild kit and do another rebuild on it and see if I can get closer to fitting everything using a thinner filter as you suggest and see if the top filter is required or not.

    Thanks for the info.

  4. #4
    Carburetion 'sucks' !
    Join Date
    Jun 2013
    Location
    Driving 'round the M25 so fast the centrifugal force is forcing my face against the side window!
    Posts
    719
    I couldn't use the GM Vette drop base as it fouled the billet throttle bracket I needed to use. The initially idea of using a 'thin' air filter element seemed a bad move considering that a 950 cfm carb is sitting up top. Surprisingly the K & N filter 'top' flows really well. Having said all that I wonder if far too much is made of carb air flow requirements - yeah, OK 950 cfm carb initially on a 489 cu in engine perhaps wouldn't seem like overkill but when you read the engine dyno figures, even at 500+ hp the calculated engine airflow usage is only around 650 cfm!

  5. #5
    Might as well be part of the furniture.
    Join Date
    Jun 2013
    Location
    welwyn
    Posts
    2,246
    Better to have the option of more rather than just sufficient

    The more I look into this I'm definitely leaning towards the Holley option as is way simpler and looks like I can keep my existing air filter element and have enough clearance above the mixer to allow for air flow. I'll show the workings in the workshop posts as and when.

    The original request for a bonnet arrangement was based on the assumption that the mixer fitted without modifying the carbs which this particular mixer will not allow. Cheers for you input.

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
  •