Welcome to the Hatteras Owners Forum & Gallery. Sign Up or Login

Enter partial or full part description to search the Hatteras/Cabo parts catalog (for example: breaker or gauge)
+ Reply to Thread
Results 1 to 5 of 5
  1. #1

    426 chrysler termostat

    Has anyone converted the thermostat housing on their Chrysler 426 engines to the following product?
    http://www.marineparts.com/p-79962-c...1968-1974.aspx
    THe issue is: My engines are running very cold.
    I put a temp gun on either hose coming from thermostat housing, and both hoses are running around 90 degrees.
    The outside water temp is 55 degrees. This is a fresh water, Raw water cooled engine.
    The thermostat is in closed position yet the hose going into the engine block is pushing through a lot of water.
    It seems like the water is somehow not getting restricted by the thermostat. I put the thermostat in hot water and it opens properly. I am assuming that there is something going on that is allowing the water to go around the thermostat.
    Any suggestions?
    PS: I first thought maybe I mistakenly put the hose that needs to go to exhaust risers to the engine intake, but then that cant be the issue as both hoses coming out of the thermostat housing is running around 90 degrees.
    Akin Tosyali
    Hatteras 41 -Barbaros

    Chicago

    Barbaros, Hatteras 41' Before and after restoration

  2. #2

    Re: 426 chrysler termostat

    They have to bypass a certain amount of water to cool the manifold and risers until the thermostat opens.

  3. #3

    Re: 426 chrysler termostat

    Dock side, at idle, in cold water,, the engines will not get up to temperature.
    As dsharp stated, some water does go thru to cool the manifolds and risers.

    Get out and put a load on them, temps should come up.

  4. #4

    Re: 426 chrysler termostat

    Thanks guys, I will take the boat out and see what happens to the temps.

    I do have a question: How much water should be flowing through to the engine when the thermostat is closed/ engine is cold?
    a-garden hose wide open (current status)
    b-garden hose half open
    c-garden hose quarter open?

    PS: I have been thinking on how this thermostat housing is designed. The thermostat itself is shaped like a cylinder sitting on a disk plate. When cold, these pieces are together. When open, the cylinder rises and a gap happens between the two pieces.
    The thermostat housing has two holes, an upper one and a lower one.
    When the thermostat is closed, water should flow only through the upper side to exhaust risers, and when it's open, it should start to flow from the lower side, to the engine.
    Inside of the thermostat housing, there is a rubber o ring that has a square wall. In theory, this o ring should prevent the water on the upper side from flowing down to the 2nd, engine intake.

    My assumption is that over time, this o ring wore out, so half the water meant for the exhaust is passing by the oring to the engine.
    So now I will measure the width of the thermostat and see if mcmaster has something I should try.
    Akin Tosyali
    Hatteras 41 -Barbaros

    Chicago

    Barbaros, Hatteras 41' Before and after restoration

  5. #5

    Re: 426 chrysler termostat

    See picture of the thermostat housing below
    Attached Images
    Akin Tosyali
    Hatteras 41 -Barbaros

    Chicago

    Barbaros, Hatteras 41' Before and after restoration

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts