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View Full Version : How Fast does ya boat go ! part 2



Lucky_Phill
23-11-2004, 11:26 AM
OK, we'll try again.

Not too sure of the jist of this topic, but.

let's put up size of boat, motor hp with max revs and max speed. A lot of boat speed will depend on prop size.

Do we need speed ?

Do we need grunt ?

I believe we have to get the maximum " performance " out of a prop. Wether that be top end speed or holeshot.

There is also a big difference in GPS speed and the water wheel hanging out the back of the transom.

Go for people, and let's have a good response !

Cheers Phill ;) ;D ;D ::)

mini696
23-11-2004, 11:38 AM
OK I'll bite...

4m centre console, 25HP and I get 18 knots average, but screaming and light on it goes at 22knots.

Also have an electric 50lb Minn Kota, get about 3-4 knots on flat water. Flat out I'll get a few hours from a deep cycle battery.

I wonder if I can get 25 knots if I run them both at once.

These speeds are GPS (across the ground), I dont have a tacho, or speedo, so I cant give many more details.

I would like a bit more power all round (holeshot and top end). I think the main problem is its an old motor, so it only feels sluggish.

But give me a bigger boat and I'll be happier.

Mickk

dfox
23-11-2004, 11:41 AM
Wheres your boat phill?
Mines a 7 meter cat twin 115 yam 4stokes
max revs 5900
max speed on gps 36.5 knotts

michael_k
23-11-2004, 01:23 PM
i have a 680 haines with 200 evinrude at 5600 doing 34knts.my 4m tinny does 25knts with 40 4st yamaha.the best part though i will be demoing a new nitro 901 cdx with a 200 optimax which will do 75 mph which aint bad for a fishing boat.

pockets
23-11-2004, 03:51 PM
Posted this topic a while back but still not sure what good performance is, but

4.75 alleycraft 60 hp 4st
45 klm p/h @5100 rev

how far can you rev out a 60 4st?

Cheech
23-11-2004, 04:40 PM
Wlcome to the site Michael. Have been out on a haines 680. Great boat.

SeaSaw
23-11-2004, 05:38 PM
Welcome Michael .... 680 Haines .... Great Boat ;D ;D ;D

Mine used to get 41 knots with a 200 2 stroke evinrude with a 12.5x19 prop and 38 knots with a 13.5x19 prop.

I now have a 225 4 stroke Yamaha and still haven't had it in flat water for full speed test but in a bit of heavy chop got 6000 rpm for 36knots with a 13.5x17 prop, but the motor was trimmed in a bit because of the heavy chop so it should go better than that.

All that is fine if you are water skiing, but the really important things are getting a good low speed plane, plenty of torque for heavy swells and a good cruising speed/fuel economy mix for offshore work. Top end speed realy doesn't mean much except to know that your engine is working in the right rev range.

Cheers,

Mark

damons33
23-11-2004, 06:27 PM
mine is a 5.2 jbs 300mm half pod(2.4m wide at the transom)
17* deadrise, ae100 fourstroke yammy(4 carbs)has a 17" prop with a 19"pitch(not sure if that correct,will check it at work tomorrow)
she gets 72kms/6300revs with the wind on ure back and flatwater trimmed right out.
she planes at 18kms/3600revs and is very stable at this speed and holds her revs like a deso'
i would give nut left nut to be able to travel at 45kms everywhere(best economy).
i thinks it a great entery level offshore boat here a photo!
i feel safe as houses in this rig, i got a furuno 1650gps colour charty and l600 sounder. 60l plumbed bait tank,14ft riggers, 8 rod rack, digi troll4 down rigger and a ipcom vhs radio. ohh and a bilge pump

michael_k
24-11-2004, 03:44 AM
mark , what revs was your evinrude doing with those props michael

SeaSaw
24-11-2004, 06:19 AM
Michael, I wouldn't read too much into the top speeds as it depends on too many variables. The speeds I have quoted were in dead flat conditions in the Bribie passage, with the motor trimmed up as much as possible without ventilating, and only a little over 1/2 a tank of fuel.

The 13.5x19 prop was just right for the boat and reved out to about 5600.

The prop I called a 12.5x19 is a different story … it was really a 13.5x19 with half an inch of blade missing. ::) When I bought the boat, it came with this prop on it. The guy I bought it from lived in Noosa and spend years taking it out through the Noosa Bar which is very shallow. Churning through sand had gradually worn a full half inch off the prop. :o That prop produced a great top end speed but it did over rev (I cant remember how high). Due to the lack of blade area on the prop, the boat had real trouble holding a plane at low speeds in any decent swell. ??? Needless to say, this prop was a dud and I replaced it immediately.

Cheers

Mark

devocean
24-11-2004, 06:21 AM
Exactly the same as Mini

ken4159
24-11-2004, 06:51 AM
5.5m JBS
115hp Tohatsu 2s
max. speed 33kn @ 5700 revs.

blaze
24-11-2004, 07:48 AM
20 foot
115 merc, 62km
4.1 tinnie
4.5 merc slow (with the tide)
cheers
blaze

michael_k
24-11-2004, 09:17 AM
MARK thanks for that ,i am currently in the process of playing with props on the haines.

michael

skippa
24-11-2004, 09:54 AM
17ft Haines
115 Yammie

skippa
24-11-2004, 10:05 AM
17ft Haines
115 Yammie
80k's @ 5500

I'm more interested that she will plane @ 12mph and hold 20mph into typical Moreton Bay chop of 15nts or more without bashin' the fillings outta your teeth.

Cheers,
Tony 8)

Mick
24-11-2004, 10:15 AM
The HMAS Adelaide.. fully equiped with automatic side mounted 50mm machine guns, nuclear war heads, heat seeking infra-red missiles, front mounted 80mm fully automatic hollow tip machine gun, 100km radar navigation, NASA satellite GPS, underwater pressure sensored missiles, sea mine tracking detectors, surface to air missiles and a pretty good anchor.

Best lap time around Australia = 2 days, 4 hours and 17 minutes (not including Tassie)

Mick
24-11-2004, 10:16 AM
Nahhhhhhhhhhhhhhhhhh, I traded it in for a 4.3 meter quintrex, centre consol, 40 on the back

roz
24-11-2004, 10:27 AM
Nahhhhhhhhhhhhhhhhhhhhhhh Mick,

My 4.72 Seafarer VC, 70 Johnson. Just organizing a photo of my pride and joy.
Roz

roz
24-11-2004, 11:01 AM
My Pride and Joy - VC3 - Cheers Roz

Lucky_Phill
24-11-2004, 12:59 PM
OK I'll bite.

6.2mtr Sportfish Supervee, Centre Cab, with a 130Hp Honda 4 banger on her bum. " ReBait ", for those who don't know.

Revs to 5500@62kph. Using a 4 blade 13 1/4 x 15 Solas S/S Prop. Cruising rev is 4200rpm and at that rate will use .65 ltrs / klm ( loaded , )

The design here is to get a holeshot for bar work, therefore top end is reduced.

Further, my 4.1 Stessl Edge Dingy has a 40 Yam 2 stroke w/ ss prop, and will boogey to 65kph, 1 up on the river. But that is scarey. ! Usually run it trimmed in for bay and offshore work, which brings her back to 55kph ( if one can go flat out offshore ).

Cheers Phill

Spaniard_King
24-11-2004, 01:18 PM
Howdy

Haines Hunter 580 Breeze

130hp Honda 4 banger

13" x 17" 4 blade solas

It definately has hole shot ;D and I have had her to 38knts [smiley=2thumbsup.gif]

NQCairns
24-11-2004, 01:29 PM
4.2m aluminium CC (old hull) with 30hp Johnson, 42km/h GPS, 2.0 to 3km/L cruise.nq

Big_Kev
24-11-2004, 04:17 PM
Haines V16R with a 90 Mariner and 17 prop(to small)
It goes fast enough for a fishing boat and is comfortable enough for the wife to come out with me now and then.
Cheers Kev.

Heath
25-11-2004, 06:15 AM
Cruise Craft 600 Explorer
175 Yamaha
19" SS Prop

48kts with clears off, half a tank of juice

bugman
25-11-2004, 06:44 AM
Lighting 6500 6.5m plate half cab
Honda 130 4 banger
3 blade prop - unsure of pitch
5500@58km
4200@38km using around .6-.7 litre per kilometre

Bugman

Zeeke
25-11-2004, 07:27 AM
4.3m Kakadu Seahunter Sideconsole.. 40hp Yamaha 2stroke somewhat standard prop

3800 RPM - 22 knots
4500 RPM - 26 knots
5000 RPM - 28 knots
5250 RPM - 31 knots

Havent pushed it further then that..

Tim

Lucky_Phill
25-11-2004, 12:40 PM
take it out of First gear Tim !

Cheers Phill ;D ;D 8)

SCOTTYGC
25-11-2004, 02:12 PM
3.8 m blue fin , 25 hp evinrude
gose flat out everywhere
scotty

Cloud_9
25-11-2004, 03:46 PM
posted this before but!
Cloud 9 4.8m C/C 90 Merc 2's 5400 revs 20" pitch laser 2 42kns 2.8Km's/L
4000 revs 30kns 2.2Km's/L
Titanic 3.5m V punt Mariner 9.9 offshore. standard ally prop 34Kph 2 up
fuel consumption is so good im making a 5Liter tank because it took 7 weekend trips to use 1/2 a 23liter tank . 5L is good for about 80Km's

its not really an 9.9 Offshore but the guy the built it for me called it that has long shaft 20" most 9.9's are 15"shaft

Cheers Cloud 9

philip_thomson
26-11-2004, 11:51 AM
i have a hianes hunter 5.2m half cabin has a 96 model evinrude 90 on the back with a 3 blade prop. at 2000rpm it sits happily on 6knts (gps reading) at 4000rpm it sits on about 23knts (gps reading) and at 5000rpm it sits on 31knts (gps reading) i find that there is a 3-4km/h difference between gps and the boat speedo reading.

cheers phil

SeaHunt
26-11-2004, 12:55 PM
GPS is most likely correct.

Wild_Side
27-11-2004, 01:18 PM
This is my poly waffle. Up here she'ill sit on around 70mph, but when in the wet stuff she only does half of that. ;D ;D 8)

Wild Side [smiley=evil.gif]

Wild_Side
27-11-2004, 01:19 PM
DOH forgot pic

Wild_Side
27-11-2004, 01:25 PM
Hey Phllip does that really work, keeping your live baits in a bottle? :o :o ::)
What do you catah on them doggy mackerel I expect...hehe :P