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Thread: Water in the oil

  1. #1
    Mel
    Any ideas on what is happening we are running a 454 BBC which gave us this problem last year with water in the oil. This winter we installed a new T valve had heads checked for cracks had block magnifluxed and pressure tested all came back ok..Its a brand new motor again all new parts.. Took her out for her first trip this summer and pulled her out of the lake after one trip arround suspected something and found water in the oil again.. Sugestions, ideas, help! Really getting tired of this

  2. #2
    Racing Ray
    I would check over the intake fit and also check it for leaks

  3. #3
    MoJetBoPar
    Hi Mel
    The first thing I would do is pull each spark plug and check it to see if one is really clean from that cylinder pulling water or possibly oil fouled.
    If they check out OK then I would suspect an intake leak as mentioned above.
    I'm new to Jet boats but if the gate valve is open too much maybe there is too much pressure in the cooling system for which ever gasket that gave in. And the motor would run too cool too I would suspect.

  4. #4
    froggystyle
    Two things you should ensure when building a motor, both I learned by being ignorant and doing it again. When you put on your intake, noone uses the front and rear cork gaskets. Use a bead of clear silicone well mated up to the gaskets on the sides. All they do is try to force the aluminum manifold off the gaskets. Next, use what is commonly in the industry termed "gorilla snot" (3m Weatherstrip adhesive) around your water ports on the intake. Use some on the bottom, and some on the top before you apply the manifold. The next item is that your head bolts need to be sealed as well, as they go right into water passages. Use a permatex "Aviation form-a-gasket" it comes in a small can, with a brush lid. This stuff gets very stiff, but does not harden. Use it on all of your head bolt threads. The same should be used on your intake bolts that empty into water jackets. If everything else works, this should stop all of your leaks.

  5. #5
    rstover1
    I agree with every one I just want to add a couple of things exaust logs could be cracked if you have them. Also if you took alot of water on it will get in through the front and rear oil seals. My dad had this problem on a sleekcraft.

  6. #6
    jaqquuuz
    I might also add that if you have an aluminum intake it might not be seating correctly. Sometimes once they get out of shape its hard to get it to seat right after awile,also like froogy said use silicon and get rid of the cork.

  7. #7
    Mel
    The intake on the 454 is cast iron I sealed the head bolts when I put the motor together I sealed the intake manifold the only thing I didnt do was put the sealer arround the water port on each side of the gaskets. I am running my side that pulls the water in open and the outside about half to 3/4 open is this right? Would not sealing the water port be where I am having the problem of water in oil.? We only ran the boat for about 15 minutes never took her above 3500 rpms and the temp never got above 120 when I decided to pull her out and check.. ended up with about a half a quart of water in the oil.

  8. #8
    froggystyle
    My guess is yes. Or a warped surface on the head/block surface.

  9. #9
    Senior Member
    Join Date
    Feb 2009
    Posts
    2,626
    I had this problem years ago on my Olds. Changed intake and head gaskets and haven't had any problem since. There was nothing visibly wrong with gaskets, manifold, heads or block. There has been considerable discussion of this problem on the Real Jet Boat forum(http://disc.server.com/Indices/152642.html).
    Even if you started out with flat, clean sealing surfaces and assembled with good gaskets and sealants, running the inlet water valve wide open could easily cause you trouble. Typical car installation might see 15-18 psi. Your pump can make a couple hundred psi,if i'm not mistaken. Many people are now using regulators between pump and engine to control this. Another area to consider would be the water injection to your headers. If you have too much water going to headers at idle and low rpms, some can actually get drawn back into the cylinders and be pushed down past the rings into crankcase. I run logs, so haven't had to worry. Again, check the RJB forum or post up your question there. You will get lots of helpful info.

  10. #10
    froggystyle
    Common concensus from the guys I asked about this is that you probably have a stuck T valve. If you pull apart your "T" valve and find that the marble is puched down into your spring, that is bad ju ju. More than likely the cause of your watering. Rewarders I guess are bad design on the valve, as very little is keeping the marble from moving into the spring, where the Bassett valve has a "triple wrap" on the top, and does a great job of preventing this.

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