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Thread: Antifouling!

  1. #51
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    Default Re: Antifouling!

    Quote Originally Posted by petem View Post
    I doubt that a bit of fouling on the upper section of the leg would be that critical.
    No reason to have any doubt about it.
    In outdrive (or outboard) powered boats, any fouling above the cavitation plate, no matter how bad, is irrelevant to the performance at planing speed.
    Mind, keeping the whole leg clean is a good idea anyway, if you care about its conditions.
    It's amazing how barnacles seem to be able to eat aluminum, if you give them enough time...

  2. #52
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    Default Re: Antifouling!

    Quote Originally Posted by jfm View Post
    Yup, none at all. That pic is my springtime lift out, maybe April, after a year in the water and after a winter when the boat goes to sea once a month for "exercise" when the sun is out, but doesn't do a lot of time/miles underway, so the barnacles have good opportunity to grow. The yard I use sprays hydrochloric acid and then a strong jet wash, and it all comes off easily

    BTW I also do not antifoul the inox H+B hilo platform lift mechanism
    Yup, I guessed that you didn't bother antifouling that mechanism, which btw shouldn't affect the boat performance for the same reasons of my previous reply to petem.
    Otoh, I'd expect those props to make life a fair bit harder for the engines.
    Do you have any idea about how much is the speed loss (and/or the load and egt increase, if by chance you checked that on your displays) vs. clean props?

  3. #53
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    Default Re: Antifouling!

    Quote Originally Posted by Portofino View Post
    Put Hurricanes, “ best prop seen so far “ shape on my boat correctly sized dia wise ( not the exact same ) or put suitable more performances oriented like mine ( again suitable dia ) and I think they will produce adverse results .
    Don't worry PF, the virtual cigar I awarded to hurricane props was among those "posted so far in this thread", most of which are related to somewhat similar boats, btw.
    Dismissing the props of your boat (whose shape btw I can't for the life of me remember) was not my intention by any stretch of imagination!
    Last edited by MapisM; 14-02-18 at 13:17.

  4. #54
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    Default Re: Antifouling!

    Quote Originally Posted by MapisM View Post
    Otoh, I'd expect those props to make life a fair bit harder for the engines.
    Do you have any idea about how much is the speed loss (and/or the load and egt increase, if by chance you checked that on your displays) vs. clean props?
    Oh yes, for sure. I don't run long cruises with props like that, and even after lift/antifoul in March/April I lift again in August the day before I go to Corsica etc for a long cruise. Or get a diver. The lift is e1000 and the diver e200, but the lift is better because it is nice to have a clean hilo mechanism for swimmers etc.

    In winter I just stay local, a few miles at d speed mostly, so the bad condition of the props does not hurt the engines.

    When the props are like that, top speed would be off by 5 knots and fuel burn would be something like 20 litres/mile rather than 15/16. I wouldn't run it at P speed for more than a brief moment, though of course the c32 is the strongest engine in its class and the one best able to take "abuse", having 1.5x the dimensions and displacement of the MAN/MTU 1500-1600bhp engines. But anyway it is perfectly ok and there is no "abuse" at D speed

  5. #55
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    Default Re: Antifouling!

    Aha, I see. All understood and agreed, including your last statement ref C32 vs. MAN.
    Now that I got to know MAN engines a bit better, thinking that they are now pushing up to 1900hp out of their V12 block is almost a practical joke, when compared to the C32...

  6. #56
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    Default Re: Antifouling!

    Quote Originally Posted by jfm View Post
    ——— / ——- of course the c32 is the strongest engine in its class and the one best able to take "abuse", having 1.5x the dimensions and displacement of the MAN/MTU 1500-1600bhp engines.
    Not wanting to pour ammonia on your parade
    Coments on this anybody?
    https://forums.cat.com/t5/Engine-Roo...ats/td-p/72727

  7. #57
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    Default Re: Antifouling!

    Well, I suppose the only fair comment could be "show me a man, and I’ll show you a crime"...
    It's a pity that LS1 is not around the asylum lately, because he surely could write you a book on this whole subject.
    Me, all I can say just having seen both the C32 and the MAN V12 blocks in flesh, is that the latter tuned to give the same output as the first is pushing the envelope to say the very least.

  8. #58
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    Default Re: Antifouling!

    Quote Originally Posted by MapisM View Post
    M, I meant to ask before but I forgot. Do you know who the builder of your props is?
    They get my vote for the most advanced props posted so far in this thread - and not because they are shiny in your pics!
    Don't know who the prop manufacturer is but, I agree there is lots of shape to them.

  9. #59
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    Default Re: Antifouling!

    Quote Originally Posted by MapisM View Post
    Aha, I see. All understood and agreed, including your last statement ref C32 vs. MAN.
    Now that I got to know MAN engines a bit better, thinking that they are now pushing up to 1900hp out of their V12 block is almost a practical joke, when compared to the C32...
    Agreed that seems a lot of power from a relatively small block but I guess the attraction for boat builders is that the MAN V12 is relatively lighter than the C32 (not sure whether that translates into lower cost) and of course lightness adds speed. Actually I've got to liking the MAN V12s in my boat. Touch wood I've never had a problem with them and they give smooth torquey performance. But as you commented on another thread, the thought of those 96 little valves whizzing up and down, any one of which could really ruin my day, does keep me awake at night sometimes

  10. #60
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    Apr 2011
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    Default Re: Antifouling!

    There are soooo many variables from taking a solid road / truck / locomotives block , upping the output then marinising it .

    If you read the link above , I get issues with cooling instal from Sunseeker and there a suggestion / blame handed about regarding inadequate warm up time as well .
    I don,t think there are any FL 78 , owners with the same issues , handing out “ abuse “?
    Also another bit of goss —— unlike our MAN,s which have arguably a keen cooler strip down clean regime - for ever .

    Latest CAT policy is chuck away coolers after say 5/7 years apparently one of them ,I think it’s the charge air corrodes from the inside and eventually goes .
    So they have rewritten the service book to change out - whole part

    JFM I understand s has retro fitted a freshwater flush system on his boat ,so presume that may extend the life .
    MAN coolers are happy sat in seawater — sure may salt up buts that’s taken care of in the service schedule.

    Re block size / relative weight , - jury’s still out for me —- instinctively bigger - more iron the better .
    Buy to counter that appart from the obviously extra kg,s , I,am thinking heat distribution.
    In a high stressed variant some % grater out put than was originally intended in a liesure boat then cooling is king to longevity.— that’s accurate targeted cooling by the fluids on both sides it becomes critical and hot spots can develop in the marine vs that’s not manifested on the lower powered road vs .
    The more extra iron hanging about the less control over the hot spots ,it’s the differential heat distribution that’s leads to cracking - so big is not necessary best as it’s born out ^^^ in the link
    Things are not allways what they seem

    On a different subject of the iron work / block dims —- look at the D12 - highly regarded on here — except one tiny little detail the pan leak .
    Nip up the bolts - New gasket , - new pan etc ——
    Nope what’s actually hapening is the block twists under load .
    The H shaped webbing can,t cope with the 715 / 800 or what ever it’s now asked of .

    So yup I would be a bit scarred if the new C32 with 1900hp was able to keep cool for long enough in use ,if not a new block / head s
    And if the latest MAN 24 L V12 pushing 1900 Hp was using the same block as the 1390 , 1550 Hp variants .

    Around 2000 Hp I would be looking at MTU V 16 ,s ——— even more valves to loose sleep about
    Last edited by Portofino; 14-02-18 at 15:05.

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