How green is your engine ?

Sonar · 12 February 2010, 08:15

So what size engine on what size boat do you have ?

fuel consumption and top speed in knots.?

I have 2 x 50 hp 3 cylinder bf 50 Hondas on a 5.6 mtr 30 knots top speed using approx 10 gallons an hour .
I say approx depends on sea conditions. 2 persons on board..
The pair have done 300 plus hours.in 12 years.

willfinch36 · 12 February 2010, 08:16

Im not sure about fuel consumption.

But 5.20M Valiant 70HP 4 Stroke Suzuki

33 knots

9D280 · 12 February 2010, 08:38

Green? Mine's painted black!

No idea on fuel consumption due to itr self destructing, but there have been at least 2 previous threads already on this subject - have a sech for them.....

Nasher · 12 February 2010, 08:44

Sonar

Hi.

I’m afraid ‘Green’ and ‘The Nashers Revenge’ are a bit mutually exclusive.

In fact I’d suggest that the only ‘Green’ RIB is one made from renewable forest wood, rubber impregnated cotton tubes and a Bloody great area of sailcloth instead of an engine.

However since you ask.

6.5M Ocean
Suzuki DT200EFI, which is a two-stroke so burns oil as well.
Cruising at @25knots uses @1.25 l/mile
Flat out at @45knots uses @3.5 l/mile

However both the boat and engine were re-cycled by me, which is a damn sight better for the environment than building a new one.

Nasher.

PeterM · 12 February 2010, 08:52

1 200HP - optimax 2 stroke - V6. 52knts flat out on a flat sea - on a 7.5m .

Using about 80lph at this speed.

As for Green - not a chance !

small boat 1 50hp 4stroke - 31 knts flat out on a flat sea - on a 4m .

Using about 15lph at this speed !

Much Greener !

Sonar · 12 February 2010, 08:53

Quote:

Originally Posted by 9D280

Green? Mine's painted black!

No idea on fuel consumption due to itr self destructing, but there have been at least 2 previous threads already on this subject - have a search for them.....

New members may have an interest in the topic.

And as you say has been asked before.
And I guess so have many many other topics and will continue to be re asked over the years to come.

chewy · 12 February 2010, 09:34

Before my 60hp two stroke stopped working I got through 12 litres in half an hour, that was on and off the throttle.

ecoXR24 · 12 February 2010, 12:13

For planing boats, the all-up weight is probably the most important factor. Length, hull shape, prop and engine efficiency all play a part of course. Power: weight ratio is the main thing that affects speed, so for two similar boats using the same power, the lighter one will go faster or use less fuel. If people can have a stab at the all-up weight of their boat when they post on this thread, the answers will be more useful, e.g. my hull should be ..., carrying 100 litres of fuel, 4 people and one small dog, or whatever.

We have a graph of power versus speed for various all-up weights on our website: http://www.eco-marine.co.uk/xr-range.html The figures are from a well known text book and apply to boats in general, not just RIBs. Fuel consumption is more-or-less proportional to power, so where the graph shows a heavy boat needs twice as much power as a light one for the same speed, it will use twice as much fuel.

9D280 · 12 February 2010, 12:45

Quote:

Originally Posted by Sonar

New members may have an interest in the topic.

And as you say has been asked before.
And I guess so have many many other topics and will continue to be re asked over the years to come.

OK, so I didn't have time to search the threads out earlier, but for starters:

http://rib.net/forum/showthread.php?t=33803
http://rib.net/forum/showthread.php?t=33598
http://rib.net/forum/showthread.php?t=31168
http://rib.net/forum/showthread.php?t=20150

Sonar · 12 February 2010, 13:10

Quote:

Originally Posted by 9D280

OK, so I didn't have time to search the threads out earlier, but for starters:

http://rib.net/forum/showthread.php?t=33803
http://rib.net/forum/showthread.php?t=33598
http://rib.net/forum/showthread.php?t=31168
http://rib.net/forum/showthread.php?t=20150

Many thanks I will start going through them all.
Again many thanks for the information.

Respectfully
Robert

JSP · 12 February 2010, 13:13

5.4m Searider with 115hp 2 stroke. Most I've had out of it was 45 knots on the flat. Spent an hour at around 38-40 knots and used 50ltrs in an hour.
There was 2 people on board and 50, 49, 48,47,46,45.......3,2,1ltrs then someone shouted 'Get back into the dock quick!'

Cruising, doing around 20-25 knots, 2 people and around 100ltrs of fuel. Going from Fleetwood to peil island (around 10nm) used approx 9ltrs.

ribmad · 12 February 2010, 23:42

im new but have been reading the fourm for a couple of years always usefull info :-) .
i've got a 50HP evinrude 30Lph at 5500rpm giving a top speed of 38Kts (but that might have been the the fast fleetwood tide) 15Lph at 16-20 Kts

biffer · 13 February 2010, 06:35

keep goin lads, i'm still the greenist, i don't do fuel calc's but yamaha i think quote 17l per hour at full revs, but i am a diesel

chewy · 13 February 2010, 07:55

Quote:

Originally Posted by biffer

keep goin lads, i'm still the greenist, i don't do fuel calc's but yamaha i think quote 17l per hour at full revs, but i am a diesel

Anyone with a Volvo inboard are surely the greenest.....

biffer · 13 February 2010, 08:52

Quote:

Originally Posted by chewy

Anyone with a Volvo inboard are surely the greenest.....

only in colour, supercharged and turbo on the same engine, mmmm, be interesting to know