| Author | Post |
|---|
randypike
Member
| Joined: | Sat Mar 14th, 2009 |
| Location: | Houston, Texas USA |
| Posts: | 18 |
| Model: | IP440 | | Hull #: | 35 | | DSC ID: | |
|
Posted: Sat Mar 6th, 2010 05:54 pm |
|
I have started planning the delivery of my IP440 from Bradenton, FL to her new home on Galveston Bay, TX. I have a couple of questions that I would appreciate your wisdom on.
1. What is the average fuel consumption for a 440 at your preferred rpms?
2. Who is the best life raft manufacturer?
Thanks,
Randy Pike
S/V Moondance
IP 440, Hull #35
____________________
Randy
S/V Moondance
IP 440 #35
Houston, TX
|
djmarchand
Member
| Joined: | Tue May 27th, 2008 |
| Location: | |
| Posts: | 167 |
| Model: | | | Hull #: | | | DSC ID: | |
|
Posted: Sun Mar 7th, 2010 05:41 pm |
|
Randy:
I don't have an IP 440, but I think I can answer your question about fuel consumption. Most long didtance trawlers use about 20 horsepower per 10,000 lbs of displacement to achieve hull speed. Sailboats should do about the same, maybe better.
Your 440 is listed at 32,000 lbs but will be 36,000 or greater full loaded. So it will take 72 horsepower to hit hull speed. That is consistent with your 75 hp engine.
But hull speed is not where most long distance cruisers operate. Most cruise at probably 20% less where horsepower is significantly reduced. Looking at Robert Beebe's book (ediited by Leishman) shows how this horsepower is reduced by approximately half.
So lets say that you cruise at a 1.1 speed to length ratio which is 1.1*sqrt (lwl). Your 440's lwl is about 40' so that is 7 kts. This will take 36 horsepower. Thirty six horsepower will require abut .06 * 36 = 2.2 gallons per hour. So you will get 7/2.2= 3.2 NM/gal. Sorry to be so technical, but you can work out your own fuel consumption with your own paramaters. These numbers are conservative and an efficient hull with a modern diesel will probably do better.
Bradenton to Galveston is about 650 NM. Your 160 gallons of fuel capacity will get you more than half way. Check Jimmy Cornell's book to see about winds during that period. But you can probably expect mostly southerly winds in late March. Any front that pushes through should only give you a day of westerly or northwesterly winds. You should be sailing above the gulf stream, so currents won't be an issue.
For liferafts, I don't think there is any real difference as long as you are comparing apples to apples. That is the bigger question. Real size, not stated passenger capacity, two versus three tubes, emergency food, water and medical supplies packed aboard, etc. Winslow, Avon, Zodiac are all good.
David
|
dick
Member
|
Posted: Sun Mar 7th, 2010 07:17 pm |
|
I have a 420 which should be similar to the 440. My experience is that at about 2500 rpm (around 5.5-6 knts) it burns about a gallon an hour. That gives a range of about 1000 miles depending on circumstances.
Fortunately, I have never needed to use my liferaft, but I chose Winslow, because of the manageable size and weight, and for the reputation.
Best of luck with your delivery!
Dick
|
ipsailor
Member
| Joined: | Wed Aug 6th, 2008 |
| Location: | Plano, Texas USA |
| Posts: | 23 |
| Model: | 380 ... | | Hull #: | 133 ... | | DSC ID: | |
|
Posted: Mon Mar 8th, 2010 06:31 pm |
|
I purchased a Winslow 6 person standard offshore for my 380 because of the light weight and size. I strap it to the fromt of the binacle while underway offshore. Winslow has a discount for Island Packet owners. I think I got $1300 off the list price.
Jeff
IP380-133
"Xperience"
Currently lying Clearwater, FL.
Homeport Plano, Tx.
____________________
Jeff
IP380-133
S/V Xperience
|
randypike
Member
| Joined: | Sat Mar 14th, 2009 |
| Location: | Houston, Texas USA |
| Posts: | 18 |
| Model: | IP440 | | Hull #: | 35 | | DSC ID: | |
|
Posted: Mon Mar 8th, 2010 06:41 pm |
|
Thanks. That's one hell of a discount!
Randy Pike
S/V Moondance
IP 440
____________________
Randy
S/V Moondance
IP 440 #35
Houston, TX
|
modestmeans
Member
| Joined: | Wed May 25th, 2005 |
| Location: | Missouri USA |
| Posts: | 455 |
| Model: | IP38 | | Hull #: | | | DSC ID: | |
|
Posted: Tue Mar 9th, 2010 03:28 am |
|
| While I generally agree with the fuel consumption posts I do warn you that running your engine at 2500 RPM for extended periods is not suggested by Yanmar. This low RPM will cause a diesel to suffer carbon fouling and severely shorten the life of the engine. You need to run the engine at a minimum of 70-75% of the rated RPM if you are motoring long distances. Throttling back for fuel savings is harmful on a long cruise. On my 38 this worked out to a suggested RPM of 3200. I would talk to the factory and to Yanmar before I motored that kind of distance with a new engine. Diesels need to be under load to perform well without adverse effects.
____________________
Winston
|
djmarchand
Member
| Joined: | Tue May 27th, 2008 |
| Location: | |
| Posts: | 167 |
| Model: | | | Hull #: | | | DSC ID: | |
|
Posted: Tue Mar 9th, 2010 03:51 am |
|
Winston:
Your position is a bit inconsistent. The 4JH4-TE is rated at 75 hp at 3200 rpm. 75% of 3200 is 2400 rpm which is where I would expect an IP440 to cruise efficiently.
Do a search on loading a diesel engine over on boatdiesel and see what you get. The idea that marine diesels must work hard to last is an old wives tale, probably rooted in the fact that they can work hard, but they sure don't need to. To paraphrase Tony Athens, the Yanmar guru over at boatdiesel "I have never seen a marine diesel engine damaged by running too slow."
FWIW a modern Ford F250 diesel pickup truck/Dodge Cummins/Chevy Izuzu is operating at a lower rpm and power consumption at 70 mph than the equivalent of 2,500 rpm on a 3,600 rpm Yanmar. It will take about 70 hp or less than 1/4 of its rated horsepower for an F250 to go 70 mph. If a pickup truck can do it, a marine diesel can as well.
So if an automotive diesel can survive while putting out 70 hp or about 12 hp per liter, then the 2 liter 4JH4-TE can survive long term putting out 24 horsepower. That would occur at about 2,200 rpm.
I just put 500 hours last year running two Yanmar 3gm30f diesels at 2,500 rpm which is about the same loading ratio to displacement as discussed above. Once every 100 hours or so I run it hard at 3,300 rpm for an hour or so to clean up the injectors and "blow out" any carbon. They are still going strong after 3,000 hours.
David
Last edited on Tue Mar 9th, 2010 03:48 pm by djmarchand
|
svseasons
Member
| Joined: | Fri Oct 31st, 2008 |
| Location: | |
| Posts: | 2 |
| Model: | | | Hull #: | | | DSC ID: | |
|
Posted: Sun Mar 14th, 2010 03:29 am |
|
We made the trip from Bradenton to Galveston two years ago in our IP45. If you haven't make the trip before, I can help with trip planning. Lots of oil rigs, most are lit up like New York City, but some are not.
Scott Harris
flyboy67b@gmail.com
|
modestmeans
Member
| Joined: | Wed May 25th, 2005 |
| Location: | Missouri USA |
| Posts: | 455 |
| Model: | IP38 | | Hull #: | | | DSC ID: | |
|
Posted: Tue Mar 16th, 2010 04:07 am |
|
I appreciate your reply but know at least three boaters who have damaged a new Yanmar running "slow". If you have to "blow out the carbon" then you are making my case.
Yes my numbers are wrong because in my 38 there is a 44hp Yanmar so the exact numbers are off but...the "old wives' tale" has never been updated in any of my contact with seasoned marine diesel mechanics. I take a pause and will ask around but, as I mentioned I have three confirmed cases of early rebuilds due to low loading.
Two of these experiences were credited to buying a boat on the Chesapeake and then taking the Intracoastal south. One engine packed it in by Miami. The other a few months later. Yanmar attributed the problems to "motoring the Intracoastal at 5 knots". This is from new boat owners who obviously reached out and asked Yanmar "I have a brand new boat, WTF?".
Also it is a well discussed fact in many articles and forums that idling your diesel to charge batteries is absolutely the worst thing for a marine diesel. Everything I have read (everything) has suggested loading your charging cycle with additional loads such as water making, inverter use, heavy DC loads such as SSB, TV/VCR use and the like to "load" the engine. This also applies to generator use, lightly loaded generators are heading toward eary failure.
I have an open mind but all you are telling me flies in the face of eveyone (you being the exception) I have dealt with, spoken to, and read about for the past 30 years.
Hopefully these posts will trigger a re-visitation of these issues.
____________________
Winston
|
phaiakian
Member
|
Posted: Wed Mar 17th, 2010 02:25 am |
|
just a comment on the view that "loading" an engine by reving it up is gospel good practice.
to me, load doesn't meam rpm.
i push a 14 ton boat with a 55 hp motor. at 2700 (where i run) , if that isn't enough of a load, i surrender.
the right rpm for me is the one that sounds right and moves me along at close to hull speed. when i listen to a 3200 rpm push, it just makes me uncomfortable.
i've run engines for more years and hours than i can remember. i don't blow them up, they sound great, and they last, well, forever (read: as long as me). never prolonged times at high (relative to maximum specs) rpms. am i just lucky? doubtful. am i easy on equipment? without a doubt. it works for me.
new engines blowing up in the intercoastal because they are run too slow? that's a fairy tale. cabon buildup doesn't trash an engine. shorten the life? maybe, but not from 15000 hours down to the few hundred that a boat is put through going down the coast.
so, here's a second opinion that that running an engine harder is not necessary. and running an engine at 3200 rpm instead of 2500 is harder, unless i was asleep in physics. (which is possible)
comparing generators that freewheel unless loaded, or trucks with 200 hp pushing a 2 ton chassis, doesn't jive with a displacement hull being driven by an engine that's essentially proportional to a large sewing machine.
good luck
ron hames
phaiakian 380
Last edited on Wed Mar 17th, 2010 02:45 am by phaiakian
|
GRaffa
Member
| Joined: | Mon May 5th, 2008 |
| Location: | Gulf Port, Florida USA |
| Posts: | 11 |
| Model: | IP45 | | Hull #: | 35 | | DSC ID: | |
|
Posted: Thu Mar 18th, 2010 01:35 am |
|
| I may be incorrect in my RMP setting per some of the comments. I motor-sail my IP45 at 2200 RPM and burn less than 1 gallon per hour. I find the having the main up assist up less I am directly into the wind, etc.
____________________
GRAFFA
|
Pete1Tod
Member
| Joined: | Sat Sep 6th, 2008 |
| Location: | Marine, Minnesota USA |
| Posts: | 63 |
| Model: | IP380 | | Hull #: | 12 | | DSC ID: | 338091791 ... |
|
Posted: Thu Mar 18th, 2010 01:03 pm |
|
The condition and type of prop being used is an important factor to determine efficient cruise speed and engine longevity. For example:
My 380 has a 3 blade auto prop which will cavitate at higher RPM and rougher seas, wasting fuel and placing undue stress on the engine, seals, and prop. Like Ron suggests, listening to your boat will tell you more than a calculator or engine RPM/Torque charts.
Last edited on Fri Mar 19th, 2010 01:02 pm by Pete1Tod
____________________
Loona Tech
MMSI 338091791
|
Current time is 12:52 pm | |
|
