Register now to get rid of these ads!

Technical Tech Week "Scratch" Built Dual Cowl Vents for a '32 Roadster

Discussion in 'The Hokey Ass Message Board' started by ziffer, Oct 13, 2015.

  1. ziffer
    Joined: May 4, 2005
    Posts: 151

    from michigan

    If you drive an early 30's Ford you know how hot it gets under the cowl, especially if you don't have a cowl vent. With a Duvall windshield you can't run a stock vent. Your only option is dual vents. Since this car is being built as a mid-fifties hot rod I am making all the parts out of existing stuff like a guy working in his own shop would have at that time.

    I had these from a swap meet in Auburn but the rectangular shape did not fit the angular lines of the Duvall. I want them to follow the profile like the card-stock cut outs in the first picture. 05-DSC00327.JPG
    First step is to get a true line across the cowl. This will ensure the vents are parallel to the cowl face. Using a rounded eraser on a compass allows you to trace right along the concave part of the body line and maintain a consistent distance.
    Before starting to cut into the cowl make an accurate template of the curvature of the cowl. After you weld everything you are going to get warping that needs to be hammered and dollied out to return the cowl to it's original shape. Without this you will never get the Duvall to sit correctly again.
    Next step is to find something to make the vents out of just like a guy would have in the mid 50's. A '48 Ford vent will make both of my vents. (Had to get 5 vents and housing before I had usable parts.)
    Look carefully at the beading 1/4 of an inch from the edge. It goes around the perimeter and creates a seal against the gasket. This will be a challenge to make a few pics down.

    Below is what the one vent cut into two yields.
    Using section of the original surrounds I started making surrounds for the new vents.
    The challenge comes as you try to make the vent fit into the surround you are making.
    Once you have the surround and vent mating nicely, it is time to get serious and cut into the cowl. Start with the hole undersized and make it bigger to fit. 1-DSC05217.JPG
    Next use clecos or screws to hold the assembly to the cowl and continue fitment.

  2. ziffer
    Joined: May 4, 2005
    Posts: 151

    from michigan

    A look at the underside that will need to be built out to fit into the opening. Additionally, that rounded bead seal needs to be recreated. In all, you have to block the end of the opening vertically, make a flat return to go to the edge, extend the bead, and then recreate the fold-over and edge weld it to the outer skin. It ended up being hours and hours.
    (The small hole in the corner is so I can pour POR-15 and coat the interior once assembled and stave off the rust.)

    Next, step is to use parts of the original air dam to make one for the new vent. Take a close look at the right end fully built out. Can't tell it's not factory.
    Sectioning the original vent pivot for the new vent. Modify (yellow marks) a '32 ratchet bar to hold the vent open. Brackets to hold the spring and made to use an original handle.
    Back to the car. Final butt fitting in preparation for welding.
    The view from below. You can see how the trough recess below the cowl. Also visible are dash supports and reinforcement plates I installed to secure the Duvall.

    Cool settings Low, Medium, and High 3-DSC07654.JPG 4-DSC07655.JPG
    Looking into gaping maw of the vent reveals it's ugly innards so making screens will keep bugs out and improve aesthetics. Using 24ga stainless I made a folded perimeter frame for around the stainless screen. The corners had mortise tabs to fit into each other so the mounting screws would hold the entire assembly together. (I tried to TIG the frame but the 24ga was beyond me.)
    Detail of the screen mounted and also note the right end where the bead, inner skin, fold over, etc.... were recreated.

    Vent in the car. 1-DSC00335.JPG

    Shot of the mechanicals from below.
    This is an overview, and I am not trying to make this seem overly simple. Making the vents open and then close to fit into the surround was a bitch. The vent swings on two curved arms that act much like a cam. It is not a simple radius sweep. Some Trig. and trial and error were used to get the precise fitment. Lastly, thank you to my friend Paul for consultations on this "Five minute job".
  3. choptop4
    Joined: Feb 3, 2007
    Posts: 656


    I did some on the lower cowl years a go. I think they came from a model A. yours look great.
  4. ziffer
    Joined: May 4, 2005
    Posts: 151

    from michigan

  5. Pewsplace
    Joined: Feb 10, 2007
    Posts: 2,792


    Very nice — I love the DuVall windshield.
    volvobrynk likes this.
  6. Hnstray
    Joined: Aug 23, 2009
    Posts: 11,901

    from Quincy, IL

    Very well done!

  7. DeucePhaeton
    Joined: Sep 10, 2003
    Posts: 999


    Much more impressive in person I may add.
  8. Rich B.
    Joined: Jan 23, 2008
    Posts: 761

    Rich B.
    Member Emeritus
    from Portage,IN

    Great fab work!
    lothiandon1940 likes this.
  9. That's really nice work!
    lothiandon1940 likes this.
  10. gnichols
    Joined: Mar 6, 2008
    Posts: 10,936

    from Tampa, FL

    Those look great. Nice job. Gary
  11. thommoina33
    Joined: Jun 27, 2008
    Posts: 1,048

    Alliance Member
    from australia
    Staff Member

  12. Excellent work and the dual vent's are aesthetically pleasing with the Duvall windshield,the screens are icing on the cake!

    Did you add a drain to the channels? HRP
    volvobrynk and lothiandon1940 like this.
  13. Great tech thread and beautiful work.
    volvobrynk and HOTRODPRIMER like this.
  14. Yep. Awesome. ^^
    volvobrynk and lothiandon1940 like this.
  15. Russ Tee
    Joined: Sep 2, 2012
    Posts: 106

    Russ Tee
    from Florida

    Very nice work.
  16. Great tech! No surprise "you need this $2,000 tool I happen to have" Just great hand work and great thought out process.
  17. 117harv
    Joined: Nov 12, 2009
    Posts: 6,590


    Great tech. very nice final product/s, thanks for sharing.
    lothiandon1940 likes this.
  18. Great vision
    Great idea
    Great execution.

    What's not to like ? :)
  19. czuch
    Joined: Sep 23, 2008
    Posts: 2,688

    from vail az

    Those are just bitchen. You're a metal magician.
  20. This is VERY cool!
  21. sloppy jalopies
    Joined: Jun 29, 2015
    Posts: 4,596

    sloppy jalopies

    Mikie likes it ! ... alot

Share This Page

Register now to get rid of these ads!


Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.