Rib / motor combos

Ribdude · 05 October 2015, 20:19

What RIB and motor combos are you guys running on your 15-19ft range?
What is your top speed?

jonp · 05 October 2015, 21:16

Ive got one of the latest Zodiac 550 pro tour with a 70 yam 4 stroke. This hull is quite light so the 70 is enough for this hull in my area where we rarely get days without winds below 20 knots.

I have mine with a low pitch prop (13x13) for pushing heavier loads in rough water (5 people with dive gear). Cruise speeds are 38km/h (18-19) at 4500 rpm and 57km/h (28-29 knots) at full rpm 6200.

I also dive with a mate who runs twin 150 4 strokes, his extra power only comes into play on rare calm days otherwise he is no quicker running out to the offshore island we dive around,

I get very good economy from the 70 (my second boat with one) which gives me around 3.5 km per litre. I also just sold my other boat which had the latest Suzuki 90 which was also a top performer.

JonD

Being fro the US you may find these performance figure of interest, just select the power and boats you like the look of http://yamahaoutboards.com/owner-res...ance-bulletins

TorontoDiver · 06 October 2015, 05:03

I've got a 2015 Highfield OceanMaster 590 with Yamaha 115 4 stroke on it.

General caveat: this is my first boat!

Top speed so far with four people in it has been 65 km/h at 5500 rpm.

Max load with three divers and tech gear (doubles plus two deco bottles) was in the 50 km/h range with choppy water.

Not certain what propeller I have on it and suspect somebody with better driving skills might get more top end

Cheers,
Neil

jyasaki · 06 October 2015, 15:11

I've got a Polaris Neptune 17.5' Aluminum hull RIB with an F115. One up with a light fuel load, it'll run a tad over 40 mph (boat was built pretty wide to get deck space.) With a few passengers it tops out in the 35 to 32 mph range depending on load. Running in the Pacific Ocean (or associated bays) I rarely get to run flat out, so the power goes mostly towards staying on plane and mitigating shock from swell.

jky

MatFromPoland · 06 October 2015, 18:09

HIGHFIELD OM540DL (5,4m ALU RIB)
EVINRUDE 115 HO, prop VIPER 14 3/4x19"

850-900 kg full setup (boat, enginem, 100l fuel, 30 liters spare fuel, 1 Gal spare oil XD100, two batteries, 2 anchors, el. pump, ...). Checked weight of boat on trailer so I'm really sure of this weight.

My family plus snorkel equipment (me 90 kg, 3 kids and wife 4 x 54 kg) I think total 350 kg ( crew + equipment )

Top speed - 69 km/h (calm Sea in Greece)

Polish lake (windy day), 9 persons on board (4 adults and 5 kids - about 600 kg)
Speed was 62 km/h (I was sure that it was 65 but when dump data from Garmin top registered speed was 62)

https://www.youtube.com/watch?t=1&v=oIMYgx8Mrk4

Ribdude · 08 October 2015, 00:18

thanks guys for the info

is anyone running a 150-200hp motor in that boat size range?

MatFromPoland · 08 October 2015, 05:44

Quote:

Originally Posted by jonp

I get very good economy from the 70 (my second boat with one) which gives me around 3.5 km per litre. I also just sold my other boat which had the latest Suzuki 90 which was also a top performer.

I'm jealous

I have never checked fuel economy when was alone on boat. Always with family. So my fuel economy is 1.8 - 2 km per 1 liter (2 adults - 3 kids about 300 kg in total), but speed always near 50 km/h (if Sea conditions allows that).

@RibDude - only people with smaller RIBs have reported here.
ZODIAC 550 max is 120, max for mine is 115. Nobody uses bigger than MAX on plate I suppose. I saw in Greece small local made RIBs (5,5m) heavy, solid with EVINRUDE 150.

jyasaki · 08 October 2015, 22:35

I'd expect that as Mat says, the manufacturer limits will come into play. I flirted with the idea of a 150 on mine, but realistically would rarely have the chance to use at the top end (though the additional grunt at the low end would be nice when needed.)

Given the litigious nature of the US (where idiots always try to get someone else to foot the bill for their own stupidity), I doubt you'll find many RIBs that size that would "legally" be allowed that much power.

jky

headdamage · 10 October 2015, 05:08

My 440 Hurricane has a Johnson 60hp 2 stroke and will just hit 58kph.

MatFromPoland · 10 October 2015, 11:10

Quote:

Originally Posted by headdamage

My 440 Hurricane has a Johnson 60hp 2 stroke and will just hit 58kph.

WOW !!! Fantastic results. 2T rules

What prop do you use ?

Technically/theoretically speaking mine VIPER 19" can not go faster than 72 km/h (gear ratio is 2,28; RPM is 5600 so as results this PROP can not give more at this RPM than 72. So 69 km/h is really good results - slip is between 5-3%.

Someone told me that VIPER blades are curved and as a results you can count this prop as more than 20" prop really.

Of course different prop you will select for race on flat lake, different for real Sea conditions.

Pikey Dave · 10 October 2015, 14:03

Matt, if you get the chance, try a Mercury Rev4 prop. Drop an inch off the pitch from your normal 3 blader.

.....sh1t happens.......

MatFromPoland · 10 October 2015, 17:45

EVINRUDE dealer from Chania (Greece, Krete Island) has advised me to try EVIN REBEL 19".

I have good experience with 4 blades also. My spare is Korean ALU 4 blade:

14x20

The same top speed than VIPER, not so perfect acceleration and go to plane like VIPER but better fuel consumption on 3800 - 4200 RPM. Everything with Family on board (5 persons).

Full load (9 persons) - VIPER does better (speed and fuel economy)

I think that I have maximum possible engine for this boat. 115 HO is downgrade 135 if I remember. So my set accept even so big props without any problem.

Now I have problem - which one test next ? Merc Rev4 or REBEL 15 1/4 x 19"
Some dealer told me that REBEL is for V6 only but the same has been mentioned about VIPER 14 3/4 x 19.

115 HO has bigger gear-case than normal 115 I think.

Chris · 11 October 2015, 07:00

Why are you changing the prop...? 69kph from with your rib/engine combination seems fine. What are you RPMs at full 69kph ?

MatFromPoland · 11 October 2015, 07:53

I'm happy about top speed and performance.
Someone told me that maybe on REBEL I will have better fuel economy and the same performance. Now it is 1.8-2 km per liter.
I'm only curious.
I'm aware of "do not correct things if they works fine ..." also

Chris · 11 October 2015, 08:43

Quote:

Originally Posted by MatFromPoland

Now it is 1.8-2 km per liter.

I'm aware of "do not correct things if they works fine ..." also

That's good fuel consumption as well. What RPM are you getting at full speed ?

Pikey Dave · 11 October 2015, 09:43

4 blade props are generally thirstier than 3 bladers. If you are looking for economy, stick to the 3 blade prop. A 4 blader will give better handling in the rough & can run higher.

.....sh1t happens.......

MatFromPoland · 11 October 2015, 13:43

5600 RPM I suppose.
Boat reach 69 km/h really fast.

Person who set-up boat in Poland want to lift engine up.
It is deep V boat and now anti-ventilation plate is on the same surface than keel. Manual states that:

Quote:

conventional v-hulls often perform well with the anti-ventilation plate approx. 1 in above the bottom of the hull

The question is "is my RIB conventional V-hull"

Chris · 11 October 2015, 14:38

The anti vent plate should skim the top of the water when you are planing and trimmed out. If it is under water then it is too low and should be raised.

5600 RPM is good.

MatFromPoland · 11 October 2015, 18:50

We will raise it next year and check results. He prepared transom for such need when set-up engine. There is -5 C around my house every morning since more than week.

So boat went to winter sleep:

I did WINTERIZATION and get out batteries.

headdamage · 13 October 2015, 22:26

Quote:

Originally Posted by MatFromPoland

WOW !!! Fantastic results. 2T rules

What prop do you use ?

Technically/theoretically speaking mine VIPER 19" can not go faster than 72 km/h (gear ratio is 2,28; RPM is 5600 so as results this PROP can not give more at this RPM than 72. So 69 km/h is really good results - slip is between 5-3%.

Someone told me that VIPER blades are curved and as a results you can count this prop as more than 20" prop really.

Of course different prop you will select for race on flat lake, different for real Sea conditions.

I'm using a Turning Point Hustler 13.25" x 17" three blade Prop.