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Caterpillar C-18 Acert 1150 Operating Temperature

Discussion in 'Engines' started by intouch1, Oct 3, 2014.

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  1. intouch1

    intouch1 New Member

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    Caterpillar C-18 Acert 1150 hp

    Am having a question concerning my engines. Kindly bear in mind boat is located in Red Sea, with elevated ambient and sea water temperatures.

    In winter, both engines would run at 90 degrees centigrade at any rpm. Beginning of summer I started noticing temp ranges in the 95 degree range. Both engines exhibit same behaviour with a nominal difference of maybe 1 degree.
    On my last cruise a few days ago, the engines would sit at 95 degress at 1750 rpm. Opening her up to 1800 would evelvate temps to 97. Upon reaching 98 degrees at 1830 rpm and reduced throttle to get temp down.

    If idled, temperature goes down to 81 degress in a matter of a few minutes.

    Boat has only 100 hours and the impellers look fine so does the discharged cooling water.

    The Manual of my Engines states the coolant temperature warning at 103 degrees centigrade but states no operating range.

    I spoke to CAT Concierge, and they said if no alarms it is fine to operate the engine at whatever Speeds that do not set off the alarms.

    Today I asked my captain to do a Trial while keeping the engine hatch open from start. Maximumtemp reachet at 1800 rpm was 93 on one engine and 96 on the other. Upon idling both engines quickly settled at 81 again.

    My gut Feeling tells me engines should be running in 90-92 degree range at all rpm ranges. 96-98 seems very high to me. However, i would then assume that Alarm would be programmed to set off lower too ??

    All Input greatly appreciated.
  2. K1W1

    K1W1 Senior Member

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    Hi,

    You might find that you have some biological fouling ( growth) on the plates of the Heat Exchangers even after 100 hrs if the boat has sat things can and will grow.

    This growth will have a detrimental effect on the ability of heat to be transferred from the Coolant that circulates in the engine to the Sea Water and will lead to elevated temps in the coolant.

    Do you happen to know how your fuel temps are now compared to how they were before? I am assuming you have the standard Fuel Cooler arrgt in the front of the Plate Cooler.
  3. Marmot

    Marmot Senior Member

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    CAT told you when to start worrying ... listen to them.

    What is your engine room ambient temperature? If the air temperature in the engine room is also quite high, you will not have the benefit of radiation cooling which means the liquid coolant heat load is proportionally greater as is clearly demonstrated by the information you provided.

    What is the lube oil temperature? You didn't mention it so may we assume it has not reached a temperature that makes you nervous?
  4. K1W1

    K1W1 Senior Member

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    Good Point, Charge Air Temp is also a good indicator of a higher ambient temp which in turn will show up in elevated exhaust temps.
  5. intouch1

    intouch1 New Member

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    thank you for the inut gents.

    exhaust temps are stable at 41 degrees on both engines.

    i did not check fuel temps but will do so.

    i doubt i would have too much growth, as engines cool down rather quick when not loaded and as both engines are behaving very much alike. i believe if there was an issue, the discrepancies would be larger ?

    strainers look perfectly clean as if filled with bottled water. no growth and no sediments.
  6. intouch1

    intouch1 New Member

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    i am only seeing elevated coolant temp. all else sems to be fine. engines run smooth.
    ambient temp in engine room will be rather high with 35 degrees weather.
    boat is a V62 sportscruise. so engine room is not the largest.

    i have tried running with hatch open, which brought down the temps by 3 degrees.
  7. intouch1

    intouch1 New Member

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    my main concern is how safe it is to run the engine at 98 for Extended periods.

    CAT says not to worry or if i cant reach max rpm with normal temps, larger heat exchangers would have to be considered. boat is still under warranty.
  8. karo1776

    karo1776 Senior Member

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    I would guess considering conditions in the Red Sea you are normal. I would keep the heat exchangers checked more regularly. Those engines are sprinters and at high power they have some limits... with high ambient and sea temps and high power expect to run close to the max. Even if you go over 100 degrees C but don't hit the limit you should be OK. The worst thing is not to run them regularly and then just do sprints... that can get expensive! Warm them up to operating temps oil, and water before sprinting... and be sure to run once a week or so.

    If you keep them operating regularly, maintenance up they will do well but do expect if you run at high power a lot it will show up in the valves and seats first. Same if you don't keep them up to snuff but you may burn a valve... with the associated problems... also you will also get some cylinder scuffing at top of the stroke if you don't run them regularly and overdo the throttles!

    The below are all the same engine...
    Been awhile since I posted this but this is what happens... Here are engine like yours... set around then sprint..

    Looking inside investigation...
    https://www.youtube.com/watch?v=9EWzakPhUu8&list=PL80AA604FE59D8D36&index=4

    what happens to a cylinder after a valve goes...
    https://www.youtube.com/watch?v=9EWzakPhUu8&list=PL80AA604FE59D8D36&index=4

    Rebuilding but shows the parts surface rust from sitting around... those get replaced... expensive

    https://www.youtube.com/watch?v=zUjGeLRt7Zc&list=PL80AA604FE59D8D36

    Offshore has a couple other videos of these high output c18s on there you tube account
  9. K1W1

    K1W1 Senior Member

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    If CAT says you can run it at the temps you are getting go for it. CAT will be able to interrogate the engine via ET to see how long it has been run at what load condition. Your engine output leads me to believe these are E Rated.

    Plate coolers can be extended in size by adding plates, it is not as big a job as changing shell and tube coolers.
  10. intouch1

    intouch1 New Member

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    thank you for the valuable Information.

    i run my engines about 2-4 hours a week....for a total of maybe 150-200 per year.

    i am easy on the throttles and always make sure temps are set before going above 1300 rpm.

    i hardly ever go up to 1850 or 1900....usual cruising is at the 1800 mark.

    at 1750 the engines sit at 95 degrees exactly....it was at 1850 that i saw 98 and eased off not to run into overheat Alarm. at that stage i was not Aware that the Alarm will only set off at 103.

    ambient temperatures are slowly on the decline now, so i will know the effect of that within the next couple of weeks. sea water will remain elevated for another 6-8 weeks i believe.

    as said earlier.....in the beginning when i tested the boat i had her up to 2100 rpm and all was fine. iirc temp sat it the 90-92 range.

    i am just surprised that the difference in ambient conditions would result in such high fluctuations between summer and winter. i would have imagined the colling System to cope better.
  11. K1W1

    K1W1 Senior Member

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    When I spec an engine I ask for it to be 25% oversize as a minimum and with twin sea inlets the whole system must run on one only, this enables a sea water inlet to be kept isolated and clean in the event of sucking krill etc into the working one, I also like to carry spare clean baskets so a change can be made in minutes
  12. karo1776

    karo1776 Senior Member

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    Well... sounds all good and K1W1 advice is better than I could do... !

    I don't think you are really taxing them... 1800-1900 rpm... they go to 2300 WOT.
  13. K1W1

    K1W1 Senior Member

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    Karo, Thanks for the endorsement.