Exhaust manifolds & risers replacement- saltwater use and kept on trailer

Discussion in 'Sport Boats' started by GoFastr, Aug 28, 2017.

  1. GoFastr

    GoFastr Cool Runnings GOLD Sponsor

    145
    Jan 20, 2016
    Cayman Islands
    2003 Sea Ray 270 SunDeck MX 6.2L MPI w/Bravo III
    Tow: 2012 Ford F150 Raptor SVT
    Mercruiser MX 6.2L MPI w/Bravo III
    Well upon thinking I only had a leaking hose on the port side, and when I went to change it the leak didn't go away.

    I ran the engine on the muffs on the trailer and for the first 5 mins all looked good. After about 15-20 mins I noticed that along with the water coming from the exhaust that was warm, I also had some water dripping from the drain plug which felt cool and didn't feel as warm as the exhaust water.

    Off came the port exhaust manifold and by tapping it with a small hammer to get the rust off I see a crack between the 2 center bolt holes.

    Bummer....but at least I now know the issue of why it seemed to run well when first going out and harder to plane off when coming back in. Dang boat was full of water!

    As the engine ran longer and got warmer over time I guess the metal expanded and leaked water into the bilge and the pump couldn't keep up with it.

    Looking for more parts again!

    https://goo.gl/photos/zLB8xw8a9N7kauEL8
    [​IMG]
     
  2. scoflaw

    scoflaw Well-Known Member SILVER Sponsor

    Aug 10, 2011
    cape cod mass
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    Your joking right ? You never noticed all that rust till now ?
     
  3. GoFastr

    GoFastr Cool Runnings GOLD Sponsor

    145
    Jan 20, 2016
    Cayman Islands
    2003 Sea Ray 270 SunDeck MX 6.2L MPI w/Bravo III
    Tow: 2012 Ford F150 Raptor SVT
    Mercruiser MX 6.2L MPI w/Bravo III
    The manifolds were all painted black until I started to wire brush them to clean them up. Then I took the hammer and was tapping them all over to hear the difference in sound while trying to find if there could be a crack in them. In the engine compartment of a 210 Sundeck you can only see the top of the manifolds anyway. It's a reach and feel process to do anything else! I know they are terrible and need replacing. I doubt if the previous owners ever changed them so 18 years is pretty good use! I was hoping to get away with just a hose change and not have to go through this expense with a boat for sale!
     
  4. GoFastr

    GoFastr Cool Runnings GOLD Sponsor

    145
    Jan 20, 2016
    Cayman Islands
    2003 Sea Ray 270 SunDeck MX 6.2L MPI w/Bravo III
    Tow: 2012 Ford F150 Raptor SVT
    Mercruiser MX 6.2L MPI w/Bravo III
    So....from what I have been reading and researching it seems that aluminum exhaust manifolds are probably only better to use on engines with similar metals like aluminum heads and FWC.

    Stainless Steel exhaust manifolds seem to be for open air engines to show off the bling like jet boats and other people with a lot of money.

    I'm thinking of getting a new set of manifolds, spacers & risers, dry joint, cast iron E-coated type for my 270 Sun Deck with the 6.2L. This way I'll have new ones on the boat that I plan to keep and taking the 1 year old dry joint manifolds off of the 6.2L (Reman'd engine in 2016) and putting them on the 210 Sun Deck with the 5.0L boat that I need to sell....which would be a sort of upgrade from wet joint types.

    Is the concensus that cast iron manifolds with the E-coating would be the best alternative and the most durable...especially for salt water use, standard raw water cooling and not slipped but kept on a trailer?

    https://www.perfprotech.com/mercrui...t-riser-kit-ek-merc-v8-c-ns-dj/product/478952
     
  5. scoflaw

    scoflaw Well-Known Member SILVER Sponsor

    Aug 10, 2011
    cape cod mass
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    If the 5.0 isn't dry-joint now, you'll need some hoses as well
     
  6. KevinC

    KevinC Active Member

    918
    Feb 25, 2011
    Long Island, NY
    2004 340 Sundancer
    1988 Proline Center Console - 90hp Mariner/Mercury
    1969 Boston Whaler
    Twin 8.1 V-drives
    If you are selling the boat and want to cut your expenses a little you might be able to find a kit from Barr. I have used them in the past and they were quite nice. Also, when ordering your risers make sure you get the proper exhaust angle.

    I am not sure what is entailed with the dry joint conversion but it is the preferred method since the water passages in the spacers were thin walled and tended to fail early and without warning.

    On a side note - all else equal this work should be an asset when selling. Make sure prospective buyers know that it was just done and educate them about the costs involved if they had to take it to a dealer or mechanic. This will definitely make your boat more appealing to an educated buyer.

    -Kevin
     

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