Fuel Consumption 75hp engine..

[goboatingnow]

Mind what blows out of the gulf of Lyon. Nasty

[boatman61]

Originally Posted by goboatingnow

Mind what blows out of the gulf of Lyon. Nasty

Yup.. experienced it a few times, mind there's some nasties blowing outa NE Africa from Monday onwards..

[boatman61]

Well that was a long conversation that led to nothing.
I rejected the delivery after arrival in Cartagena and am now back home in Portugal.
Thanks to all who responded.

[Pizzazz]

Originally Posted by PineyWoodsPete

No way would running @ 1800 under way and charging at this more efficient RPM be anywhere near 1.3 gal/hr if you can believe the Yanmar-75 factory charts above. 1800 gives you ~10 kW/13.3 HP prop power, so charging ~1kW/1.3HP @ 80A 12V would add very little.

Not that it makes a significant difference but charging via the alternator does toke some power. 80A x 14V = 1.2kW / 55% efficiency = 2+ kW or nearly 3 hp. Adding another 2-3 hp just to turn the engine, you can assume that charging takes 6 hp or approximately 1/3 gph.

[Rumrace]

The 430 claimed a range of 600k miles, likely in forgiving waters. Solar panels or a Gen set would be secure additions. A panel comes apart on your aft starboard quarter transom and there is a right spot for the Onan. You can also add a second alternator, with a clutch because it gobbles up horsepower. Keep in mind running a motor runs the transmission nice and hot too.

[boatpoker]

Originally Posted by Snore

My generic SWAG is 1/4 GPH (1.2LPH) per 25hp at 1800 rpm. 90%of the time the estimate is high, except westerbekes. Those engine are 15%more.

Really ?
My Westerbeke (Mitusbishi) 55A gulps 0.75gph at 1800rpm and 7.2nmph in our 38 footer.

[StuM]

Originally Posted by boatpoker

Really ?
My Westerbeke (Mitusbishi) 55A gulps 0.75gph at 1800rpm and 7.2nmph in our 38 footer.

That consumption would be about right when under power, and driving a propellor through the water to move the boat. (But I'm a bit suspicious about your 7.2knots at 1800RPM unless you are severally over-propped. That's only about 8 Prop HP according to the Westerbeke figures for a typical prop configuration.)

But more to the point, since the main point of this thread was running the engine for battery charging, not for motoring: how much does it sip at 1800rpm in neutral with the alternator being the only load?

[boatpoker]

Originally Posted by StuM

That consumption would be about right when under power, and driving a propellor through the water to move the boat. (But I'm a bit suspicious about your 7.2knots at 1800RPM unless you are severally over-propped. That's only about 8 Prop HP according to the Westerbeke figures for a typical prop configuration.)

But more to the point, since the main point of this thread was running the engine for battery charging, not for motoring: how much does it sip at 1800rpm in neutral with the alternator being the only load?

Never measured it in neutral. Let me make the number even more doubtful it only has a w/l of 34 6" and wake is tiny and she is a little over propped, she makes 2700rpm at full throttle.


I have found over the years that for any curve you can come up with there are some boats that simply won't fit, None of the three boats I've had fit the curves but one of them is really far out...

Monday Morning 40' single 235hp Volvo TAMD 60 B, almost no bow rise at full acceleration and very difficult to tell the difference in wake at 10kts or 20.
1.8gph at 10knots
7.8gph at 21 knots
She's doing 17knts in the photo below.