fuel burn rate Perkins 4108

[robert c young]

I historically planned at 1 GPH, but even with a freshly scrubbed bottom I
recently noticed it was closer to 1.2 or even 1.4GPH when I was in a rush
over the course of 31 hrs. of running. I found a couple hundred RPM makes a
big difference in consumption but only +0.2 KPH in speed. Moreover, the
engine ran hotter too.

Regards
Bob


-----Original Message-----
From: passpor...@googlegroups.com
[mailto:passpor...@googlegroups.com] On Behalf Of P. Sherwood
Sent: Friday, August 24, 2012 11:27 AM
To: Passpor...@googlegroups.com
Subject: [Passport] fuel burn rate [was: Holding tank replacement]

With a 4.108: I plan for a burn rate of a gallon an hour but barring
especially difficult circumstances usually burn around two-thirds to
three-quarters gph, as nearly as I can figure.

Phil
s/v Cynosure

On 8/24/2012 05:50, Brian Moloney wrote:
> ... what sort of mileage do people get (esp.
> the Nanni owners)?
>
> Brian
>

--
Passport Owners Association http://passportyachts.org To post to the group,
use "reply all" or send email to Passpor...@googlegroups.com To reply to
just the author, just use "reply:
For more options, go to
http://groups.google.com/group/PassportOwners?hl=en

[Bill Casnovsky]

I get 0.8 GPH at 2300 rpm on my 4108.

Bill Caz.

s/v P40, Beau Navire

[robert c young]

Hi Guys,

 

I am finding this data interesting and I think we as a group may be curious to know the following:

 

 

If you want to send me the data, I would be happy to volunteer to put it all into a spread sheet and send the summary around to the group in an effort to see what are the “normal” ranges for boats assuming a clean bottom. I guess refrigeration on or off may slightly influence this too, but I think most would have the frig on if the engine is operating. I do not remember the prop pitch on my Maxprop so I would just put N/A in such cases.

 

rcy...@optonline.net

 

Regards

Bob

[jo...@ets247.com]

I get .75 gall per hour at about 2350. Speed usually about 5.5 to 6.O KTS. 3 blade fixed.
John

Sent from my Verizon Wireless BlackBerry

---

From: robert c young <rcy...@optonline.net>

Sender: passpor...@googlegroups.com

Date: Fri, 24 Aug 2012 12:57:20 -0400

To: 'Bill Casnovsky'<bcasn...@gmail.com>

Cc: <p...@witanco.com>; <Passpor...@googlegroups.com>

Subject: RE: [Passport] fuel burn rate Perkins 4108

[Larry Byers]

I use about .7/hr @2200rpm and go 6 to 7 knots depending on how my three-blade Gori prop is engaged. My engine is a Yanmar 4JH4E with I think 55 HP.

 

Lare

S/V Rocinante

Panama Cell: 507 6157 8322

US: 425-381-3974

www.voyageofrocinante.com

Skype: LarryB262

[jean nicca]

I sailed/motored up the Red Sea on my circumnavigation.  I have Peregrine, a Passport 42 (30,000 lbs loaded) with a Perkins 4-108 with over 3,000 hours at that time.  I filled the tanks to the brim in Salalah, Oman and carried 30 gallons in jerry jugs.  I arrived in Port Suakin, Sudan and again filled my tanks to the brim from the jerry jugs.  I don't have the numbers, but remember the consumption rate, using the gallons used and the hour meter reading, was 0.85 gals/hour.  I'd say that the engine ran at an average of 2,000 rpm.  I repeated this when I arrived in Safaga, Egypt and got results that were very close.  As for speed over the bottom, at times I was making 1.5 knots some of the time in the Red Sea.   

Jean  

---

Subject: Re: [Passport] fuel burn rate Perkins 4108

To: rcy...@optonline.net; passpor...@googlegroups.com; bcasn...@gmail.com
CC: p...@witanco.com
From: jo...@ets247.com
Date: Sat, 25 Aug 2012 00:58:42 +0000

[ChinaDoll]

Watch out for % power when watching your fuel burn. Running the engine without a load at 2200 RPM will burn little fuel as the engine is running at a low % power.

Diesel contains between 18 to 20 HP per gallon; if you cruise at 2200 RPM on one day burning 0.75 GPH on a 50 HP engine, you are running with only 15 HP out of a 50 HP engine. Considering typical 80% burn efficiency, 50HP x .80 x 1/15HP x 100% = 38% power, at 5 KT over the ground speed.

On another day, shoving a 12 foot head sea and 30 KT head winds, just to hold 2200 RPM and maybe 4.5 KT, your engine is now consuming 2 gallons per hour. Before you could have made 400 KM out of 60 gallons of fuel, but now you'll be lucky to make 135 KM.

Here's a funny thing I have posted before: most European diesel contains nearly 33 HP per gallon. You'll get more bang for your buck on say German diesel. If you live in one of the Midwest states and have E85 gasoline, the low cost for this type of fuel is quickly lost in the lack of fuel mileage, as each gallon has less horsepower than regular gas.

-Rob.