Announcement

Collapse
No announcement yet.

Manicooler Maintenance

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Manicooler Maintenance

    How often are you removing manicooler for inspection and cleaning of heat exchanger and manicooler?

    What is average life of manicooler?

    How much does "ceramic" coating or plating extend life?

    I am sure "it depends" but sharing real life experience and conditions would be enlightening.

    #2
    Very general questions with no specific data on the boat or engines past life - so here is a post written 10 years back that still applies.
    Hope it helps....


    Hino Manicoolers


    There have been numerous posts about the Hino manicoolers as of late and it appears that more information would assist owners of what to expect with these assemblies. Although the Hino engines have a unique part number for their assemblies these principles do apply to a range of similar marine manicooler engines other the Hino. In the presentation of some of these thoughts some minor liberties are being taken in analogies as well as some exaggerations in order to make a point clearer - the intention is not to mislead. Please accept this information for any value as it was intended.

    Enhancing Manicooler life - Well this is always a great idea with any mechanical device and can be especially valuable in the area of heavily loaded and expensive marine parts. While it is both admirable and prudent to take steps such as ‘ceramic coating’ of manicoolers this is to be considered ‘extra credit’ in the manicooler book of maintenance. Extra credit is the + 5 to 10 points you can get on a test after the basic 100 point score is added up. So of course this is a great thing to do but only if you have already taken care of the core maintenance items for your engines which constitute the base of your extra work.

    A place to start - Often people ask ‘how long will these manicoolers last’ and then we get a bunch of replies most of which are correct to a certain degree but lack information most often due to the way the question is asked. So let’s answer this question based upon a different set of given parameters as a starting point for comparison - ‘How long will a manicooler last if it is filled with a perfect mix of antifreeze and DI water, subjected to a constant room temperature of 65 Degrees F only, and sealed inside box?
    Well that answer would likely be something like this - “in the range of millions of years”.
    But this answer has no real value to us as we utilize our boats in varied ways and in wildly varying environments. We could begin to then discuss each and every one of these variations as a method to determine a lifespan - but that would also be very specific to each variable chosen and have limited use for us. Alternately one of the soft ‘tools’ we used to use when engineering new systems was an analysis tool that would basically ask “ how can we most easily make this part fail?”. That tool was called a force field analysis and after it was reasonably completed by the team we could gather up the best methods to force the part to fail, prioritize them, and then figure out the best ways to combat those failure mechanisms.

    How to force a manicooler failure - Although manicoolers are more robust than any of us normally would give them credit for there are a number of ways in which we can force these parts to fail prematurely. These methods can be grouped into a few categories but fortunately we are not interested in most of these categories such as hitting them with a 12# sledge hammer. Similarly we do not often talk about ignoring obvious external leaks or running the engines without the raw water valves open as we all can clearly understand those types of cause and effect failures. The area that this topic almost always intends to address are those failures which occur internal to the manicooler assembly and are directly or indirectly related to erosion. Internal erosion occurs on the manicooler when a ‘boiling’ takes place on the inside of the aluminum runners as supported by enough heat as well as a specific spot for the boiling to originate from. Now we can focus only on this particular failure mechanism of manicooler erosion and what is the best method to generate it.


    class=WordSection2>Easiest way to force a new manicooler to fail from internal erosion - We have a brand new boat that is waiting for us to force a manicooler failure but it has to be this exact failure and cannot be a previously discussed obvious ‘trick’(IE -we cannot just close the raw water valve).
    The best way to generate this erosion failure in the manicooler is to elevate the temperature as high as possible as well as limit the ability of the coolant to accept and spread out the heat. So on a new engine the easiest ways to do these two things will be the following:

    1. Overprop the boat so as to allow it to get fully on plane and to accept a full throttle of fuel load but only allow it to achieve about 90% of max rpms’s. This will allow almost a full load of fuel but not allow the engine to realize its full cooling capability from either air, water, or the oil heat transfer. Additionally items such as the engines fuel timing will be off since they are mapped to be correct only for a specific load at a specific rpm - later relative fuel timing and less air turbulence will just add more relative heat.
    2. Open the radiator cap and dilute the neutral antifreeze mixture, also add some contaminants in there (such as salt) which will further degrade the heat extraction capability as well as supply a needed point for the erosion to work from.

    These two will work pretty well together as the engine will put tremendous amounts of heat into the manicooler runners and the contaminated coolant will offer less ability to pull heat away - while at the same time the contaminants from small local spots which support the boiling inside the manicooler which generates the erosion we are looking for. All we have to do now is maintain this exact environment long enough for the erosion to work its way all the way through the manicooler. For many of us that have witnessed this treatment it will still take hundreds of hours to work its way through the aluminum runner right adjacent to the exhaust ports.

    Other methods to force this failure - By this time any seasoned boat owner is likely anxious to add all of the ‘other’ and ‘better’ ways to either add heat into the runners or limit the ability to pull the heat away. There is no doubt that you will all be correct in that there are limitless methods to add to these two areas of destruction. It is also a good time to point out that by working more than one of these methods at the same time the ability to force a local failure becomes easier. A decent example of this would be to add a single partial injector failure to our test case above which will put an even greater heat load into one runner of the manicooler. So it is also good to note how interactive all of these failure mechanisms (or maintenance items if you will) are related to one another.

    Let’s list a few ways to add combustion heat in the runner - Not intended to be all inclusive here are a few examples:
    • [*=1]Partially blocked air flow[*=1]Low turbo output[*=1]Valve adjustment[*=1]Fuel timing[*=1]Nozzle spay pattern[*=1]Head torque[*=1]Partially restricted exhaust

    And a few ways to defeat the heats escape -
    • Partially blocked strainer or raw water valve
    • Partially collapsed raw water inlet hoses
    • Raw water pump partial failure
    • ‘Mud’ buildup in coolant bundles
    • Coolant pump belts
    • Coolant pump vanes
    • Thermostat
    • Poor or old lube oil

    How about detection? - Well there is some good news here because besides the fact that you will know you are not up to date on the maintenance items there are few obvious ways to detect this coming on. They kinda fit into groups which are relatively easy to review each time out and they include baseline gage readings, exterior engine signs, combustion symptoms, and added gage protection.
    -Gage readings would suggest you take a digital picture at varied rpm’s of all of the standard gages to use as a comparison. This can then be used to see if you are drifting towards signs of extra heat in the engine. Engine temps, oil pressure, speed at a given rpm can all be indicators over time.

    -Exterior engine signs will be things like how far the removed paint extends along the manicooler runner where it meets the head, how much mud is in the bottom of overflow bottles, how much mud can we wiped off of the bundle under the rad cap, and how far the rust extends from the turbo base where it attaches at the manicooler.
    -Combustion symptoms would be smoke that is black in nature at cruise and or increased accumulated soot on the transom.
    - The best real time indicators are adding gages that read boost and exhaust gas temperatures (EGT) known as pyrometers. Both of these gages can be installed for less than a few hundred bucks and tell you much better what the engine is doing internally.

    Anything that can be done to prevent these basic causes of failures will add a good deal to the life of your engines and also allow any ‘extra credit’ you do to be worth that much more. So please prop the boat correctly and stay on top of your maintenance schedule so your manicoolers will outlive all of us.

    Hope this helps,
    Ron and Karen
    “No Worries”

    Northport NY

    Comment


      #3
      If I understand your post (which I read also in another thread), you are saying manicoolers fail PRIMARILY due to local overheating that results in "boiling" and hence erosion? I understand the "symptoms" pointing toward poor maintenance, and removed paint near the head. Great info.

      I still wonder how often people are removing the manicooler to service the heat exchanger (to find and/or eliminate "mud" buildup).

      Or, are we to assume that a very well maintained coolant system, with the right prop and engine operation allows near infinite life (6000 hours, 40 plus years) of the manicooler, without removing it to service the heat exhanger?

      Comment


        #4
        "I still wonder how often people are removing the manicooler to service the heat exchanger (to find and/or eliminate "mud" buildup)."
        Are you asking whther folks do the required standard services on these manicoolers?
        If that is the question the answer is most folks never service the manicoolers...I have seen most of these manicoolers ignored for 10+ years with littel or no attention and they still did/do OK (not great).
        If the question is what would happen if they followed the manual .... then the answer would be that they would have no problems.
        "Or, are we to assume that a very well maintained coolant system, with the right prop and engine operation allows near infinite life (6000 hours, 40 plus years) of the manicooler, without removing it to service the heat exhanger?"
        In general if you performed antifreee changes/flushes on standard intervals and also avoid purposely overloading engines the manicoolers will likely go 10-15+ years between removal for full servicing due to "O" ring degradation.
        It does depend greatly on how they have been treated already and how the engines are set up and run.

        FWIW - we have owned 4 boats with Hino engines (8 Hinos) over 30 plus seasons plus we had also worked along with many other Hino owners over the years. The HIno is quite robust compared to most other moderate sized diesels in boats ..... any engine requires standard maintenance the HIno will still 'live' with minimal/poor maintenance unlike others but it will only go on for so long.
        Hope this helps
        Northport NY

        Comment


          #5
          Thank you smitty---perfect--very helpful!

          Comment


            #6
            Often, and Smitty477 can correct me, the mud is largely the casting sand from the various parts, something that should be pretty well done by now. However, many of the manicoolers haven’t had that mud cleaned out. There’s a row of access plates on the bottom side that can be removed, drain the coolant first, and the mud rinsed out with some creative rinsing. There are no gaskets on those plates, just a good helping of RTV.
            All things being equal, think of the bundle, the heat exchanger tubes, there’s no reason it shouldn’t last. How often do you service your radiator on you car? Big rig trucks go a quarter million miles before there’s a beginning of a thought of servicing the radiator.
            I’m not saying I wouldn’t be concerned, just aware. In the case of my boat, the risers and one manicooler had failed and been replaced just prior to my buying it. Why had they failed? Lack of use and maintenance. The PO two back owned it for fifteen years and took great care of it until his admiral passed. After that he lost all interest and put the boat on the market. He didn’t keep it clean and operational and it cost him an engine rebuild. The PO right before me bought it as it was and did some of the work needed to make the boat salable.
            You can create a plan to self insure yourself for catastrophic failure, though few of us do. Create a separate savings account and put $1000-1500 in it, then add $30-50 for every hour of operation. You should be able to pay for most of your engine maintenance parts from that account. With experience, you will be able to adjust your contribution.

            plus one on smitty477’s post #4
            P/C Pete
            Edmonds Yacht Club (Commodore 1993)
            1988 3818 "GLAUBEN”
            Hino EH700 175 Onan MDKD Genset
            MMSI 367770440

            Comment


              #7
              Originally posted by Pcpete View Post
              Often, and Smitty477 can correct me, the mud is largely the casting sand from the various parts, something that should be pretty well done by now. However, many of the manicoolers haven’t had that mud cleaned out. There’s a row of access plates on the bottom side that can be removed, drain the coolant first, and the mud rinsed out with some creative rinsing. There are no gaskets on those plates, just a good helping of RTV.
              All things being equal, think of the bundle, the heat exchanger tubes, there’s no reason it shouldn’t last. How often do you service your radiator on you car? Big rig trucks go a quarter million miles before there’s a beginning of a thought of servicing the radiator.
              I’m not saying I wouldn’t be concerned, just aware. In the case of my boat, the risers and one manicooler had failed and been replaced just prior to my buying it. Why had they failed? Lack of use and maintenance. The PO two back owned it for fifteen years and took great care of it until his admiral passed. After that he lost all interest and put the boat on the market. He didn’t keep it clean and operational and it cost him an engine rebuild. The PO right before me bought it as it was and did some of the work needed to make the boat salable.
              You can create a plan to self insure yourself for catastrophic failure, though few of us do. Create a separate savings account and put $1000-1500 in it, then add $30-50 for every hour of operation. You should be able to pay for most of your engine maintenance parts from that account. With experience, you will be able to adjust your contribution.

              plus one on smitty477’s post #4
              You are right the mud can start by sand caused by the castings - the mud is a collecting of 'things' that needs a point to 'collect' on and grow into a problem.
              The TSB on flushing these engines is fairly much the same as flushing any or light truck engine with aluminum safe flushing agents (I will see if I have a copy to post)
              There are a few common ways that I have seen to get the 'mud' sooner and quicker causing overheating conditions (mud is often collated silicates):
              - old coolant collecting contaminants over time due to air exchange (replace on schedule/use overflow bottles)
              - contamination from salt/fresh water on the raw water side due to failing "O" rings (check for unknown added or low coolant levels)
              - improper coolant used containing high silicates (use low or no silicate coolant)
              - mixing incompatible coolants on changes or top-ups (use correct and compatible coolants - never mix types of coolant)
              Northport NY

              Comment


                #8
                TSB Hino cooling system flush....
                Attached Files
                Northport NY

                Comment

                Working...
                X