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  1. #51
    Join Date
    Dec 2005
    Location
    Live London
    Posts
    3,840

    Default Re: Fairline Squadron 58, Volvo D12-715 evc- experiences?

    An cam is vital ! So much simpler and no shouting to explain what the anchor is up to especially if it gets stuck !

    Consumption 18kts 1600 rpm 130 lph

    The boat had just been relaunched which was the last photo I took of the plotter showing consumption.

    8 kts. 30 lph. Bear in mind planning boats roll when going slow unless sea is flat

    Consumption rises signfiantly when props fouled. Hull impacts of course but props really kick it in the teeth and are well worth 30 mins with your snorkel. An earlier pic showed 160 lph at 18 kts with dirty hull etc and it only got worse from then on. Temps rise also.

    Cost benefit is marginal as in Mallorca lift and foul is about e3500 !

  2. #52
    Join Date
    Mar 2002
    Posts
    17,639

    Default Re: Fairline Squadron 58, Volvo D12-715 evc- experiences?

    Quote Originally Posted by jrudge View Post
    Consumption rises signfiantly when props fouled. Hull impacts of course but props really kick it in the teeth and are well worth 30 mins with your snorkel. An earlier pic showed 160 lph at 18 kts with dirty hull etc and it only got worse from then on. Temps rise also.
    Beware of rising temps J, because that shouldn't happen, theoretically.
    I mean, it makes perfect sense that with fouled props the engines must run harder (=higher load and hp output) at any given rpm, burning more fuel.
    And that means more heat to dissipate.
    But the heat exchangers should be man enough to cope with the max heat that the engines can generate, which is at full load and max rpm.
    Below that, they should never struggle to do their job.
    In other words, the closed cooling liquid should stay constant, courtesy of the thermostat opening and closing as required.
    So, if you see the temps rising while cruising at 18kts, I would suspect that the heat exchangers might be clogged, at least to some extent...

  3. #53
    Join Date
    Aug 2016
    Location
    Bergen, Norway
    Posts
    51

    Default Re: Fairline Squadron 58, Volvo D12-715 evc- experiences?

    Thank you, for the consumption numbers, jrudge.
    As MapisM said, the temperature shouldn't increase, even with dirty props or hull.
    Long time since you checked/ cleaned the heat exchangers, or maybe the check the impellers? Sounds like you might not get the normal water flow.

  4. #54
    Join Date
    Dec 2005
    Location
    Live London
    Posts
    3,840

    Default Re: Fairline Squadron 58, Volvo D12-715 evc- experiences?

    Quote Originally Posted by MapisM View Post
    Beware of rising temps J, because that shouldn't happen, theoretically.
    I mean, it makes perfect sense that with fouled props the engines must run harder (=higher load and hp output) at any given rpm, burning more fuel.
    And that means more heat to dissipate.
    But the heat exchangers should be man enough to cope with the max heat that the engines can generate, which is at full load and max rpm.
    Below that, they should never struggle to do their job.
    In other words, the closed cooling liquid should stay constant, courtesy of the thermostat opening and closing as required.
    So, if you see the temps rising while cruising at 18kts, I would suspect that the heat exchangers might be clogged, at least to some extent...
    Exchangers are now clean. The main rise was saw was on a trip to ibiza at about 24/5 knots On the way back having cleaned props temps down and consumption down by 350 l one way

  5. #55
    Join Date
    Aug 2016
    Location
    Bergen, Norway
    Posts
    51

    Default Re: Fairline Squadron 58, Volvo D12-715 evc- experiences?

    Could the sea water intake and/or hoses be partly clogged, limiting sea water flow through the heat exchangers?

  6. #56
    Join Date
    Dec 2005
    Location
    Live London
    Posts
    3,840

    Default Re: Fairline Squadron 58, Volvo D12-715 evc- experiences?

    No it is all fine.

    The exhangers were slightly clogged which is now done.

    Regardless fouling = lots more fuel = more heat due to loading. If all boats can get rid of the excess or not I donít know.

  7. #57
    Join Date
    Apr 2011
    Location
    Boat- Western Med
    Posts
    5,345

    Default Re: Fairline Squadron 58, Volvo D12-715 evc- experiences?

    Quote Originally Posted by jrudge View Post
    No it is all fine.

    The exhangers were slightly clogged which is now done.

    Regardless fouling = lots more fuel = more heat due to loading. If all boats can get rid of the excess or not I don’t know.
    Picking up on the heat point ^^^^^ .
    Mine ( 13 L straight 6 MANs of 700 Hp ) are similar size and configuration as the popular D12 ,
    I ve mentioned this before they run on the plane @ 85 in the summer even near WOT , which like Jrudge I don’t go there hardly .Infact 1800 rpm is about the most I go as it’s fast enough around 30 knots .
    But when off the plane they cool so D speed 8 knots 82 and tick over marina movements even are at 79 by the time I,am ready to switch off after sorting the lines etc .

    So there’s obviously some head room on the cooling system or it’s configured for 1600-2150 rpm .
    Below theses rpms it’s always lower the jacket temp .
    Fortunately I have EGTs the real indicator of heat build up .
    Tend to run mid 500 degrees so 560 to 580 if fouled at under 1800 rpm .
    Although seen 630 at WOT on a fresh hull that’s 2150 .

    Each engines a bit different different regarding EGT ,s but reading around the subject it’s considered best in terms of longevity to stay under 600 .

    I ve always said optimum cruise in the real world should be 6/8 knots off WOT often quoted speed or lower .when planing .

    I ,am wary of boats that need to go north of 2000 rpm with cylinder sizes of 2 L and above to attain any reasonable planing speed .
    Ideally for a 2L + per pot under 1900 or better around 1800 .Talking 4 T engines here btw .So disregarding 2T , DD

    Just a thought.
    So at the sea trail set them at 1800 / 1900 and that’s your max cruise really .
    Last edited by Portofino; 20-09-19 at 11:32.

  8. #58
    Join Date
    Aug 2016
    Location
    Bergen, Norway
    Posts
    51

    Default Re: Fairline Squadron 58, Volvo D12-715 evc- experiences?

    Good to hear all is working as it should.
    Yes, fouling is a serious speed brake.

    Anyway, seems like my Fairline dream/project died before it started today. Norwegian banks for some reason don't give loans to boats older than 10 years, even though I could easily have handled the loan. Bummer!
    A few banks even confirmed that I could easily get a loan for a 9,9 year old "wreck," but not for a 10,1 (or 13 year old in my case) boat in mint condition. Logic??

    But thanks to all of you for all the valuable feedback and information you provided. Much appreciated!

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