speed with diesel?

[joakimhansson]

How fast is a diesel compare to a outboard? If you take mercrusier 1,7 and a outboard with around 115-125 hp.

And the bigger yanmar/volvo...

Can you get close to 50 knop with a 315 yanmar, on a revenger 27-29 (or simular boat).

For me diesel is slow....but you can change me...??? or..

And offcause fuelconsumtion?

[Mollers]

Speed with diesel?! Not tried it, sounds far out man! Tried Coke and Asprin once, that was crap. Got rid of my head-ache though

[codprawn]

Have a look at the EPS Tigershark - a Mark Pascoe design -

http://www.epsmarine.com/html/frames/fr_1.html

Don't know top speed but would guess maybe 65mph??? It has a surface drive!!!

[Mike C]

Originally Posted by joakimhansson

How fast is a diesel compare to a outboard? If you take mercrusier 1,7 and a outboard with around 115-125 hp.

For me diesel is slow....but you can change me...??? or..

And offcause fuelconsumtion?

You will probably go faster with the 115 o/b in this comparison. I think I am right in saying though that the Merc 1.7 is 120hp 'at the engine'.... so by the time you reach the prop it is probably nearer to 100hp. The outboards will be rated 'at the prop'. My Humber Ocean Pro with the Merc 1.7 has a top speed of around 30 knots and cruses nicely at about 23 knots. (GPS readings) Not a race winner but a good cruiser.

Outboards are lighter than diesels so they will always have more 'go' than a similar powered diesel but that doesn't mean you can't get a fast diesel set-up. You'll just need a bit more horsepower I presume! (No doubt some engine expert can give us some comparison figures on that)

However, don't cast aside the thought of diesel. There are 3 very good reasons for considering it. (Even without the current price difference in the UK)

1) Fuel economy. I recently did 2 days cruising around the Scottish Islands, logging up 130 miles on the GPS. I refuelled to a full tank with 95 litres of diesel. That’s 0.73 of a litre per mile!

2) Fuel Availability. Diesel is far more easily available at the dock than petrol, (in the UK anyway).

3) You are not sitting on a bomb! If your boat catches fire, at least you have a chance of putting it out with diesel!

Always diesel for me from now on! The Merc 1.7 is a nice little engine but there are now similar sized, more powerful engines available.

Mike C

[DGR]

My Ribcraft 7.8 has got the 315HP Yanmar engine with a Bravo 2 leg, and can just about get to 40 kts (GPS) on a flat day. It is a heavy boat though, so something lighter might go a bit quicker.

Over the summer (250 hours) I've got through between 10 and 20 litres of diesel per hour - depending on what we are doing. The 20 litre days are the ones where I spend most of my time at max continuous revs (3600 rpm) .

Hope this helps!!

D...

[simmons0]

With our Merc 1.7 we get 40 knots flat out and cruise it around 28knots, Mike, its 116hp at the prop and a bit over 120 at the crank.

[Alan Priddy]

You should have a look at the new Yamaha 315 plus Twin Rotating Prop system. Engineering excellence. All new and will proberbly be the world leader within two years. But then what do I know? Alan P

[codprawn]

Of course you are not biased

Taken from the Yamaha website

"The 2005 Southampton International Boat Show has been chosen to host the world launch of the new Stern Drives range, which just goes to show how important the UK market is for this type of engine...
Or perhaps its because we Brits know a thing or two about good engineering, just ask Alan Priddy, he successfully took his single engined Yamaha ME420 powered Spirit of Cardiff rib for a record breaking circumnavigation of the globe..."

It does look like a a very interesting package though - wonder what the weight will be like???

[Jonny Fuller]

Originally Posted by Alan Priddy

But then what do I know? Alan P

How to blow your own trumpet?

[The Garfish]

Originally Posted by simmons0

With our Merc 1.7 we get 40 knots flat out

Originally Posted by simmons0

we hit 43knots

Originally Posted by simmons0

I get 45knots

Originally Posted by simmons0

we hit 47.7knots

fuk mee simmuns1 i fink yew mus av a derty bottum de waiy yorr bote iz lewzin spead

gArf