I thought this was interesting enough to share /manifold riser gasket

TrashmanTrashman New Jersey/ philaPosts: 272Member ✭✭✭

Marine Exhaust Turbulators


turbulator1

QUESTION: What is the purpose of the “Turbulator” used in Mercruiser Marine Exhaust Systems”.

This is a question Performance Product Technologies receives on a regular basis being the leading technical source for Marine Exhaust products and technical information.  The history of the “Turbulator” dates back to 1932 if you look at the original patent filings for such devices. However the most similar design to the way it was patented and is currently being used by Mercruiser dates back to a patent filed by Jerry Gilbreath, who at the time was the owner of Gil Marine. Gil Marine was later purchased by Corsa products and later sold to CP Performance who now produces the Gil Exhaust systems through their Hardin marine division.

turbulator2turbulator3

The basis for the “Turbulator” stems from the need to prevent condensation generated within the exhaust system from entering a Marine Engine through the exhaust manifold and riser. Through the basic process of combustion the exhaust temperature generated with the standard internal combustion marine engine reaches approximately 650F – 750F when idling. With the “Cold Manifold” type cooling systems (click on this link to read more about cold versus warm manifold cooling systems) the cooling jackets of the manifold and riser never reach much above 100F. The result of this 650F versus 100F temperature difference is much like what you will see with a cold glass of iced tea sitting outside on a hot summer day. The result: excessive moisture condensing within the inner passages of the exhaust. In some cases the amount of condensation can be enough to actually cause engine misfire if the exhaust is configured such that enough of this condensation makes its way back into the engine.

 

Without going into a full blown engineering analysis of the “Turbulator” we will provide a brief explanation of how it functions. The basic premise is based on the following design intentions;

  1. The angled section of the plate creates a small reservoir once clamped between the exhaust manifold and riser/elbow (see image directly below). This reservoir then acts as a trap to catch and contain any condensation that is collecting on the internal exhaust passages. This reservoir also collects and water that may be present in the exhaust gas originating from water reversion.
  2. The reduction in cross-sectional area as the exhaust flows through the “Turbulator” causes a low pressure area within the reservoir of the “Turbulator” itself at the very point where the condensation is collecting. As the exhaust passes through the “Turbulator” and the reduction in flow area the exhaust gas velocity increases which allows the exhaust gas to pull out any condensation collected in the reservoir, that hasn’t already been evaporated by the heat of the exhaust.

turbulator4 copy

 

Therefore in summary the “Turbulator” is an effective design at helping to reduce the effects of condensation however the best overall approach in our opinion is the “Warm Manifold” type cooling system. The “Warm Manifold” cooling system design offers other advantages such as more consistent temperatures, better results at preventing moisture from reaching the engine, etc. The following links point to the various Mercruiser product locations where you will find the “Turbulator” being used;

Comments

  • reneechris14reneechris14 Pawcatuck river CTPosts: 506Member ✭✭✭
    Thanks for sharing,good info
    2005 Rinker FV342  boat name "Ten Forty"  Pawcatuck river,Ct
  • craigswardmtbcraigswardmtb Mystic, CTPosts: 773Member ✭✭✭
    Alot of the performance guys with big blocks will remove this thing all together to get better exhaust flow and a few more ponies for their go fast boats.  For me its not worth the risk.  The taller the riser the greater the need would be for the tubulator as the water will have more surface area to condense on.
  • craigswardmtbcraigswardmtb Mystic, CTPosts: 773Member ✭✭✭
    The other thing to remember is gaskets go on top and bottom of the turbulator.  On my 496's that equals 6 gaskets per engine.
  • Cableguy GregCableguy Greg Pittsburgh, PAPosts: 2,441Member ✭✭✭✭
    The other thing to remember is gaskets go on top and bottom of the turbulator.  On my 496's that equals 6 gaskets per engine.
    Really??? The Merc parts catalog doesn't show multiple gaskets on the risers or the exhaust manifold for the 6.2's. I am getting ready to do my exhaust manifold, so I guess I will find out the hard way.
    2008 280 Express Cruiser, 6.2MPI, B3, Pittsburgh, PA
    Go Steelers!!!
  • Dream_InnDream_Inn Annapolis, MDPosts: 3,339Member, Moderator mod
    Hey, I learned something today!!  Thanks for posting!

    Dream 'Inn III -- 2008 400 Express

  • craigswardmtbcraigswardmtb Mystic, CTPosts: 773Member ✭✭✭
    edited April 19
    I can only speak for the 496's and service manual 30.  But i would assume any manifold with a riser and turbulator would be similar.  But you know what they say about assumptions....
  • craigswardmtbcraigswardmtb Mystic, CTPosts: 773Member ✭✭✭

  • AlswaggAlswagg Posts: 1,512Member ✭✭✭✭
    Big block and small blocks exhaust are completely different.  The small blocks have the tubulator built into the manifold riser gasket but if you have an extended riser you also need a gasket without the tubulator.  Plus they need to be oriented front to back. Not all are the same.  Be very careful 
  • TrashmanTrashman New Jersey/ philaPosts: 272Member ✭✭✭
    Alswagg said:
    Big block and small blocks exhaust are completely different.  The small blocks have the tubulator built into the manifold riser gasket but if you have an extended riser you also need a gasket without the tubulator.  Plus they need to be oriented front to back. Not all are the same.  Be very careful 
     Very good info, in one of your posts you mentioned this flange and sparked my curiosity in why it was there    Obviously for  trapping and creating a suction to remove condensation that forms inside the manifold 
Sign In or Register to comment.