Reassembly of reconditioned Yanmar exhaust manifold...

Discussion in 'Diesel Engines' started by Roly, Oct 20, 2010.

  1. Roly
    Joined: Jul 2005
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    Roly Senior Member

    The proximity of salt water near my diesel freaks me out........
    A coupla questions that have been bothering me, to which I have been given conflicting advice.

    Is it advisable to put in manifold bolts in with coppercoat grease to aid removal later?
    Also, on the bolts on the raw water/ fresh water heat manifold?

    A ex-marine engineer told me not to use it (coppercoat) where salt water could interact with it, yet the instruction on the jar says it prevents corrosive binding?

    I'm told Lanicoat (Lanolin based grease) is a no-no, where higher temperatures are involved, but good elsewhere on the boat.
    Very confusing.

    Last, but not least; Can the seal of the "O" rings on the end of heat exchanger be supplemented with RTV gasket silicon or silicon grease?
    Cheers guys.

    P.s. All the bolts came out pristine.Except some of the heads were knackered from a leaking mixing elbow/end cap O ring. Hence my questions.

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    FAST FRED Senior Member

    The teflon tape used in gas appliances (thick and usually yellow) works fine on bolts you wish to take apart , eventually.

  3. Petros
    Joined: Oct 2007
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    Petros Senior Member

    the new o-rings should be used clean, the RTV should not harm it but you should check compatability with the o-ring material. Some compounds attack each other and it may shorten the life of the 0-ring.

    There is an anti-seize compound used on auto engines and machinery, I would look into a similar compound for marine application. I use the stuff sold in NAPA stores in my engine overhauls all the time, particularly on the manifolds and it works well. But I do not know the suitability for exposure to sea water for this product. There should be a similar product for use in marine application I would guess.

    Does the copper coat say it is suitable for marine application? You usually can contact the manufacturer with a specific question about it if it is not clear on the label.

    It would be a good idea to use such a compound, but you need to verify that it is compatible with sea water first, or it might react with it an make it worse.

  4. dinoa
    Joined: Oct 2007
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    dinoa Senior Member

    I've been using Loctite Nickel Anti-Seize catalogue No. 76736 on marine exhaust manifold and riser bolts, two stroke exhaust ball joints and aircraft exhaust ball joints for 20 years now with good results. Expensive stuff. A little goes a long way though. The label says "effective from -180 to 1,400C....can be used on stainless stell, aluminum, copper, brass, iron, steel and titanium".

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