"Over the hump"

[scorch]

\"Over the hump\"

Can you guys (or gals) out there help please? I have an Osborne Kingswift 27ft still on its original 4/107s with enfield outdrives. The problem is that being very stern heavy as I increase speed the bow lifts very high but cant make it over the hump to come onto the plane. With the stern digging in as much as it does, this limits me to about 11kn and the engines can only push up to about 2300 r.p.m. I have been told that trim tabs, unless v.large. will not lift stern enough. Question; will balast in the stem help bring it down? If so, how much? (boat weighs about 3 1/2 ton). Or will I need trim tabs as well or instead? many thanks in advance, Scorch.

<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by scorch on 15/02/2004 12:34 (server time).</FONT></P>

 

[hardy]

Re: \"Over the hump\"

Have similar problems with Hardy Boats, many people put weight up forward with good results. see hardy boat owners web site
good luck

<hr width=100% size=1>KISMET HARDY

 

[robind]

Re: "Over the hump"

Stick a number of plastic 5 Gallon drums in the bow and fill them progressivly untill you obtain the result you want and then install a water or fuel tank under the berths permanently?
Rob

<hr width=100% size=1><A target="_blank" HREF=http://www.rejuvanu.com>RejuVanu</A>

 

[Talon]

Re: \"Over the hump\"

I think the last place you will want balast is in the stern, you really need that up the front if anywhere. Easiest way to sort that out is to get friends to sit up the front, you will soon know how much you will need.

Trim tabs help a lot.

Can you angle your outdrives so the props are tucked under the boat a little more, this way you will have a bit of downward thrust to help lift the back up.

When we put our boat on the plane, we tuck the legs under, around -4, trim tabs all the way down, once up over the hump, we move the legs out and lift the tabs and set her up. Without doing this she will get there eventually, it is all just a lot slower.

/forums/images/icons/smile.gif



<hr width=100% size=1>Alex

<A target="_blank" HREF=http://www.mad-als.com>http://www.mad-als.com</A><P ID="edit"><FONT SIZE=-1>Edited by Talon on 15/02/2004 17:11 (server time).</FONT></P>

 

[sailorman]

Re: \"Over the hump\"

i think if u re-read it he states "stem" old term for front

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[Talon]

Re: \"Over the hump\"

Does that mean that Port is the old term for right?? /forums/images/icons/wink.gif

<hr width=100% size=1>Alex

<A target="_blank" HREF=http://www.mad-als.com>http://www.mad-als.com</A>

 

[sailorman]

Re: \"Over the hump\"

wot about larboard then

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[longjohnsilver]

Re: \"Over the hump\"

Suspect that with those engines and outdrives you'll have real problems planing.

As others have suggested try getting a bit of mobile weight (ie people) forard and see what happens. More weight at the stern I suspect will only make matters worse.

Good luck, they're a good boat, but to get planing performance you'll probably need new engines and outdrives!

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[ccscott49]

Re: \"Over the hump\"

Port, right, I hope not!

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[Talon]

Re: \"Over the hump\"

I hope not as well, I prefer a brandy myself....

<hr width=100% size=1>Alex

<A target="_blank" HREF=http://www.mad-als.com>http://www.mad-als.com</A>

 

[ccscott49]

Re: \"Over the hump\"

Nice vintage port! Mmmmmmmm

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[ccscott49]

Re: \"Over the hump\"

Nice vintage port! Mmmmmmmm Gout injection!!

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[Talon]

Re: \"Over the hump\"

Naaah, well yeah it is nice, but give me a glass of Remi XO any day!!

Is it me or is the forum slow tonight?

<hr width=100% size=1>Alex

<A target="_blank" HREF=http://www.mad-als.com>http://www.mad-als.com</A>

 

[starboard]

Re: \"Over the hump\"

Get a few of your mates to move onto the bow as she approaches the hump....see if that helps, if so it will give you an idea as to weight distribution and trim. That is easilly demonstrated by weight shift in an inflateable dinghy...only a small movement forward will put the beast on the plane.

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[ccscott49]

Re: \"Over the hump\"

Forum is very slow!!

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[sailorman]

Re: \"Over the hump\"

just looked "whos on line"
if u got us lot on the "sharp-end" u would have an egg whisk x 2
gues thats why the forum is vvvvvvvvvvvvvvvvvvvery ssslo

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[truebrit]

Re: \"Over the hump\"

I would have thought that there would be no chance of planing a boat weighing three plus tonnes with 70-80 bhp.trim tabs or bow ballast would increase speed,but only by keeping the bow down and hence maximum waterline length,and then only by perhaps a knot or so.

<hr width=100% size=1>Mike....... V8s are sweet music

 

[aztec]

Re: \"Over the hump\"

iv'e got a kingswift, so's a mate of mine...

mines on 1600 petrols, my mate's on 4107's..

forget it, she won't plane... or at least ours won't .. not enough power...

originally the "boat show" one (kingfisher) had 115 volvo's running VP legs, she could plane... but at a cost. expect at best 14Knots from yours with the right props.

you don't say but is yours a Mk 1 or 2?

mine's a heap that is in need of a thourough refit.. so if you have any photo's???...

let me know, cheers, steve.

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[itsonlymoney]

Re: \"Over the hump\"

So does that meen that "No you can't have it" is old term for
"of course you can buy that new boat darling you know you dont need to ask" ?

Regards-Ian

<hr width=100% size=1>Play the best game you can with the cards you've been dealt ! ! !

 

[brianrunyard]

Re: \"Over the hump\"

3.5 Tons with at the most 100hp, gives a max speed of approx 14 knots with about 10" pitch props.
As the 4107s are probably only producing 40 hp each (if you're lucky) 13 Knots would be absolute maximum.
What props have you got?
Regards,
Brian

<hr width=100% size=1>Brian
http://homepage.ntlworld.com/brunyard