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Volvo D-12 engines

Discussion in 'Engines' started by Terriseefeldt, Jun 14, 2022.

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  1. Terriseefeldt

    Terriseefeldt New Member

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    what is the proper operating temps for twin 715 hp Volvo D-12. Engines?
  2. Fishtigua

    Fishtigua Senior Member

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    Water in, water out. Why are you asking?

    Ex-Volvo guy here.
  3. Terriseefeldt

    Terriseefeldt New Member

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    When we are running around 20 knots the engines are getting up around 197-198. We had the heat exchanger acid washed, but it’s still hot. Impeller is okay too
  4. mapism

    mapism Senior Member

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    Speed as such doesn't tell much.
    Depending on the boat, you might be either at max rpm and full load, or at a relatively low rpm/load, or anywhere in between.
    Anyway, full rpm/load aside, coolant should be about 10 deg lower than that, by and large.
    Beware of acid washing heat exchangers, that only cleans the raw water side but the fresh water side might still be dirty.
    It takes a full removal for a proper job, the rest is just corner cutting.
  5. Sea Gull

    Sea Gull Member

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    I run D13-1000s. Since new they run at 189-190 at cruise speed. Never seen them higher than 190, even at WOT.
  6. Fishtigua

    Fishtigua Senior Member

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    And the water inlet is how big while up on the plane?
  7. DOCKMASTER

    DOCKMASTER Senior Member

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    is this a new issue? When did it start? Any changes other than acid wash of the H/E’s? What temps did they run previously? What load % are you at when seeing these elevated temps? Do temps climb further with more throttle?
  8. mapism

    mapism Senior Member

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    It's fair to expect that the builder fitted a large enough inlet, I reckon...
    ...and I can't think of any reason why that should have been changed/restricted afterwards.

    OTOH, it would be interested to hear the answers to Dockmaster's questions.
  9. gr8trn

    gr8trn Senior Member

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  10. Fishtigua

    Fishtigua Senior Member

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    The inlet and outlet of cooling water is a pretty basic plan for most of us.
  11. Scott M

    Scott M Member

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    I ran a pair of D-12 800's for many years and they always ran 183-85 at 80% load. At WOT, I would see 190, but nothing as high as you are seeing.
  12. Fiammetta42

    Fiammetta42 Member

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    Use a hand held infra red gauge on the thermostat house or HE body to determine if the sensors / dash instruments are accurate .