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craigtoo 03-09-2008 07:30 PM

Westerbeke 27 - Diesel Consumption Rate
 
Hello,

I'm taking my boat up the ICW in a week or so.

Sabre 34
approx. 12,000 lbs
Shoal Keel
Westerbeke 27 - 1700 hrs.

If we assume calm conditions, little or no wind - calm seas....
engine is in good working order.

She cruises between 5 and 6 knots at 2100 rpm.

Very roughly speaking...
How many Gallons per hour can I expect to burn?

Again.. I'm not looking for exact numbers.. just a rough idea.

I'm digging through old posts...and the Westerbeke website... to no avail...

Thanks,
Craig

Freesail99 03-09-2008 07:42 PM

I read something saying that a 23 to 27 hp diesel burns on average .33 to .38 gallons per hour. I can't find where I read that at the moment. I was looking at the same trip myself.

citation34 03-09-2008 07:46 PM

I have a 20 hp Yanmar three popper in a 11,500 pound Irwin Citation 34 and I'm averaging about 2.25 hours to a gallon which is really good.

tjaldur 03-09-2008 07:50 PM

As a rule of thumb, a diesel engine uses 0,2 litres of diesel pr. HP/h. That is if the engine if 100 HP then you will use 80% of the total capasity in top revolutions. Assuming that this is 2000 r/min. Then you will use 16 litres/h. If you reduce the speed to 1000 r/min, the consumption will be 4 litres/h.

(Double the speed, square the consumtion, half the speed, squareroot the consumption, interpolate for values in between)

craigtoo 03-09-2008 08:06 PM

Free, Citation thanks.. that's what I'm looking for...

tjaldur - Thanks for the information.. .Help me with my math.

27 HP @ 80% = 21.6 HP
21.6 HP x 0.2 Liters / hr = 4.32 literes / hr
3.8 litres / Gallon

= 1.13 Gallons per hr
This is way too high.. What did I do wrong?

Thanks again,
Craig

Rockter 03-09-2008 08:27 PM

Everything hinges on how fast you motor.
This is not an exact science.
Nurse the motor and budget for about 2/3 US gal per hour.

camaraderie 03-09-2008 09:13 PM

I think that 1/2 gallon/ hour would be a safe and conservative budget unless you are really pushing the engine.
Of course you will find out shortly! Fill your tank and keep track of your miles and hours till your next fill-up...then simply divide by the number of gallons you take on. It is useful to have both numbers...and on the ICW since everything is done in mile markers...it is useful to know how many miles you get per gallon.
Bring plenty of extra fuel filters and know how to use them!! Good luck with the trip!

billangiep 03-09-2008 09:23 PM

Craig, I helped deliver a 34 Gemini. At 2800 rpm. we burned roughly 3/4 gal. per hr. and a 1 gal. if we pushed it.

craigtoo 03-09-2008 10:03 PM

Thanks all..

Cam,
Fuel filters... I'm bringing three of the racor(sp).

Also a spare water pump impeller.

Any other suggestions welcome.

thanks,
craig

camaraderie 03-10-2008 12:13 AM

Alternator belts!


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