Custom Divorced Intake Manifold

Discussion in 'Flat Fender Tech' started by jeep2003, Feb 12, 2018.

  1. Feb 12, 2018
    jeep2003

    jeep2003 Active Member

    vestal ny
    Joined:
    May 30, 2006
    Messages:
    1,317
    Iv been reading David Vizard's book on modifying A-series engines and they have an integrated manifold like the L head. He determines this is a bad thing for making power. The heat it makes goes past the point of being beneficial causing much too much gas expansion in the intake. Also makes it makes it much more susceptable to detonation which isnt a problem that iv had but the fact remains. So I thought it would be a good project to make my own intake. I settled on building the intake rather than the exhaust because it was easier, still provides access to the valve cover, and less likely to leak. The tubing is the same size as the original but the hot spot is now removed and it works as it should. I think it will help alot on hot days climbing hills especially the engine seems to loose power when being worked hard.
     

    Attached Files:

    Rich M. likes this.
  2. Feb 12, 2018
    Rich M.

    Rich M. Member

    Maryland
    Joined:
    Mar 23, 2008
    Messages:
    273
    Nice job!
     
  3. Feb 12, 2018
    PeteL

    PeteL Member Sponsor

    Joined:
    Aug 3, 2003
    Messages:
    5,349
    Cool air always helps, that's for sure.

    But I'm having trouble imagining detonation in a four cylinder flatty!
     
  4. Feb 12, 2018
    garage gnome

    garage gnome Rust polisher Sponsor

    Western MA
    Joined:
    Jun 19, 2009
    Messages:
    1,584
    I’ve been running this for 5 years or so. If you use and fhead manifold, you’ll get a little better flow.

    [​IMG]
     
    melvinm and 73 cj5 like this.
  5. Feb 12, 2018
    jeep2003

    jeep2003 Active Member

    vestal ny
    Joined:
    May 30, 2006
    Messages:
    1,317
    Nice ! I do have an extra W-O that I could have run duals but I dont know if the added complexity would be worth it. Certainly looks great though. Ill have to keep an eye out for an F head manifold at the junk yard
     
  6. Feb 12, 2018
    garage gnome

    garage gnome Rust polisher Sponsor

    Western MA
    Joined:
    Jun 19, 2009
    Messages:
    1,584
    I tried dual WOs and they didn’t work when I tried them on Ted. The dual YFs seem to work. The fhead exhaust manifold needs a slight modification to work. Two ears need to be cut off where studs are shared between the two manifolds. Everything else lines up.

    I’ve always thought the L head, if hopped up, wouldnt be a bad little engine.
     
  7. Feb 13, 2018
    Mark Wahlster

    Mark Wahlster Member

    Silverton, OR
    Joined:
    Dec 17, 2015
    Messages:
    358
    I have modified a Pierce cast aluminum manifold for a 1500cc MG engine and a Weber DGV progressive two barrel for my intake. I'm also working on a Tri Y header design for it.
     
  8. Feb 13, 2018
    ITLKSEZ

    ITLKSEZ Volvophilic

    Post Falls, ID
    Joined:
    Aug 13, 2015
    Messages:
    1,873
    Nice!!!!

    Hey, I think it's time for some new gloves. :rofl:
     
  9. Feb 14, 2018
    garage gnome

    garage gnome Rust polisher Sponsor

    Western MA
    Joined:
    Jun 19, 2009
    Messages:
    1,584
    You should be able to find one fairly easily. I got mine by posting a WTB ad.
     

Share This Page

New Posts