|
|
22-12-2008, 12:50
|
#46
|
Moderator
Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 21,458
|
Quote:
Originally Posted by NealS
A diesel engine is subject to "wet stacking" or over fueling if run for long periods of time with ultra light loads (less than 40% of the rated output). "Wet Stacking" causes the engine to smoke and run rough because the injectors become carbonized. Running a heavy load will usually clean up the over-fuel condition and allow the engine to perform properly. Diesel engines operate better and more fuel efficient when loaded (70-80% of the rated output is optimum).
|
Thanks to Neal and David for the explanation.
I'm left with the impression that nearly every recent production yacht is doomed to this condition and the early demise of their diesels. The combination of fairly easily driven hulls and big engines means that very little of the engine's life will be running at anywhere near 75% of max, or 30-40% either. A typical 40' boat these days has a 50-70 hp engine, and requires maybe 12-15 hp to drive it to cruising speeds in calm conditions, let alone idling around in anchorages looking for a good spot, etc. Daily hours of reefer and battery charging don't help either!
The idea of routinely giving the engine a period of high load/speed to blow out the accumulated carbon seems a reasonable practice, though.
Of course, on our previous boat the engine (BMW D-35) had over 6k hours on it when we sold her, and was running well, despite this abusive life of lightly loaded motoring. Maybe it isn't too much of a problem after all!
Cheers,
Jim
|
|
|
22-12-2008, 13:56
|
#47
|
Registered User
Join Date: Apr 2006
Posts: 4,413
|
Jim,
How does one actually determine the percentage of load on the diesel? I assume that if you go full throttle in gear that is 100% load. But considering that you (I) can reach hull speed below full throttle all I am doing is burying the transom and making a steeper bow wave to climb and wasting fuel.
If hull speed in flat water is 100% and my rev is say 2000 for the sake of argument and idle is 1000 for the sake of argument can I assume each 100 revs is 10% of the load?
What is the load of a 100amp alternator and a 3 amp copmpressor at 1200 rpm or 1500 rpm?
How do you figure out the load?
And what IS a acceptable time frame to run a diesel unloaded? Or lightly loaded? If this is followed by normal loading and the carbon is burned off is there no harm?
My engine only smoke when it is cold started and it stops when it reaches operating temp range. Should I let it warm up or just "go?" when it's real cold?
You tell me.
|
|
|
22-12-2008, 14:54
|
#48
|
Registered User
Join Date: May 2006
Location: Slidell, Louisiana, USA
Boat: William Atkin Cutter, 35'
Posts: 150
|
Has anyone read BY THE WIND, by Richard Baum. My wife gave it to me 30 years ago and I am just reading it now. How enlightening for me. Really has re-aligned my priorities.
It is truly amazing to read a story such as this. No engine, no outboard, no fridge, no Epirb, no VHF, no radar, no AIS, no liferaft, no autopilot, no wind vane, hank on sails, no preassure water, no computer, no hot water heater, only paper charts, rowing hard dingy, oil driven lights (apparently), compass and RDF only.
Imagine that! How refreshing! (We do have many of those items.)
Two wonderful trips around the caribbean to the Virgins and Bahamas to Bermuda also, from the North East and no disasters or even accidents.
"Much of Seamenship is being destroyed by mechanism". He concludes that much of the truly quite and valuable peacefulness is consumed by repairing, maintaining, or worrying about questionable or unnecessary cruising items, along with all of the extra parts required, even if one has the ability to repair them.
We allow no gas on board below decks, no propane below decks either. A Honda is a neat tool, but I would need to store it on deck, that is not an option, for several reasons. Too much gas would be needed and would also require deck storage in cans, not an option.
We like to stay out, on the hook, for a month or so, from anchorage to anchorage, not in marinas, we try not to go in at all if possible. We row our Montgomery 6.8, have solar and wind power, an invertor, use oil lamps for cabin light, (even in summer), and some heat. Our solid fuel heater works well too. Awnings and wind scoops work well for cooling and ventilation.
At the dock we do have A/C and 110 heat though.
__________________
"Love My Country, Fear My Government"
|
|
|
22-12-2008, 15:04
|
#49
|
Registered User
Join Date: Jan 2006
Location: Ft. Pierce, FL
Posts: 647
|
I never meant to disparage the Honda gen as an addition to other methods, I meant this mainly for those who use and advocate it as the SOLE method of charging other than the main engine's alternator. I refer to the guys who haul it out and run it every day, or every other day.
I see how it can make sense as an infrequent addition, but those who think that it is the best sole means of regular charging, and use it every day, don't know how bad they've got it. And I don't mean that in an insulting way, I mean it in the way of a poorly stowed item that you are tripping over. After a few days of tripping over the item, you learn to step over it. After a while you don't even think about when you step over it. Then one day the item is removed, and you realize how uncomfortable it really was having to step over it all the time. If you're hauling your generator out everyday and listening to it run and feeding it gas, have a ball, but you aren't saving any money or making your life any easier.
And if you're contemplating how to keep your batteries charged when you go cruising, I would recommend solar as a better alternative than a gas gen.
|
|
|
22-12-2008, 15:08
|
#50
|
Registered User
Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,619
|
Quote:
Originally Posted by orion1
Has anyone read BY THE WIND, by Richard Baum. My wife gave it to me 30 years ago and I am just reading it now. How enlightening for me. Really has re-aligned my priorities.
It is truly amazing to read a story such as this. No engine, no fridge, no Epirb, no liferaft, no autopilot, no wind vane, hank on sails, no preassure water, no computer, no hot water heater, only paper charts, rowing hard dingy, oil driven lights (apparently), compass and RDF only.
Imagine that! How refreshing!
Two wonderful trips around the caribbean to the Virgins and Bahamas to Bermuda also, from the North East and no disasters or even accidents.
"Much of Seamenship is being destroyed by mechanism". He concludes that much of the truly quite and valuable peacefulness is consumed by repairing, maintaining, or worrying about questionable or unnecessary cruising items, along with all of the extra parts required, even if one has the ability to repair them.
We allow no gas on board below decks, no propane below decks either. A Honda is a neat tool, but I would need to store it on deck, that is not an option, for several reasons. Too much gas would be needed and would also require deck storage in cans, not an option.
We like to stay out, on the hook, for a month or so, from anchorage to anchorage, not in marinas, we try not to go in at all if possible. We row our Montgomery 6.8, have solar and wind power, an invertor, use oil lamps for cabin light, (even in summer), and some heat. Our solid fuel heater works well too. Awnings and wind scoops work well for cooling and ventilation.
At the dock we do have A/C and 110 heat though.
|
How wonderful for you and I am sure you are extremely happy and content with your choices. But the reality of cruising is that 99.99999% of the other cruising boats out there in the same anchorage you are in have gone and are going the other direction. Adding more equipment integrated with computers and every system on the boat. Entertainment is priority and TVs, DVD players, stereos and much more are now on board most cruising boats. Alarms, monitoring systems and a myriad of equipment means lots of energy use and larger battery banks. These people are not going to go back, if anything they will look for more toys and that is the reality I am sorry to tell you. You are in the extereme minority and we should not try to influence you to change your choices nor should you be too concerned about ours. It is simple for us to co-exist but you will have to deal with some ever so slight noise from those generators and we sometimes do the same with those wind generators that make so much racket we sometimes can't sleep at night.
|
|
|
22-12-2008, 15:12
|
#51
|
Registered User
Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,619
|
Fish, Just curious how you might know what makes life easier for the rest of us and what Saves us money? I would like to have that ability.
|
|
|
22-12-2008, 15:17
|
#52
|
cruiser
Join Date: Sep 2007
Location: Tampa to New York
Boat: Morgan 33 OutIsland, Magic and 33' offshore scott design "Cutting Edge"
Posts: 1,594
|
Ive never been kept up at night by my wind generator, you are kept up by others? Keep your honda, it doesnt bother me, I just found out it was unnecessary and nice to be rid of when I found out I didnt need it. I have a pretty big power appetite myself and am happy that my alternative energy feeds it. What a pain it is to have to fire up a genny on a nice quiet sail when youve been hearing nothing but ocean and the power of the wind. The windgen is music to my ears then compared to an engine running
|
|
|
22-12-2008, 15:24
|
#53
|
Registered User
Join Date: Jan 2006
Location: Ft. Pierce, FL
Posts: 647
|
Quote:
Originally Posted by Chuck Baier
Fish, Just curious how you might know what makes life easier for the rest of us and what Saves us money? I would like to have that ability.
|
I've done it both ways, and I'm good at math.
I don't have a problem with people disagreeing with my opinions. I had hoped to provoke some decent argument about why honda's are better than solar, but it seems I'm just provoking hurt feelings from honda users. I guess that's the answer in itself.
|
|
|
22-12-2008, 16:00
|
#54
|
Registered User
Join Date: Oct 2008
Location: STL MO
Boat: we don't need no steenking boat-we walk on water...
Posts: 51
|
Why use a Honda generator?
Because Chrysler, GM and Ford don't make one!
__________________
Ignorant enough to be dangerous and smart enough to know it.
|
|
|
22-12-2008, 16:00
|
#55
|
Registered User
Join Date: Apr 2006
Posts: 4,413
|
There is the possibility to have lots of electronics and communications gear, toss in entertainment electronics and you can see that one might need to generate and store some decent amount of power.
12v refer is a very power hungry creature as well, for those who need cold drinks and want to store perishables for a few days, a refer or ice is the only way to go.
Electronics, aside from back lit monitors are not very power hungry, but things with motors are, such as pressure pumps, shower pumps, bilger pumps, auto pilot drives, macerators, deck wash pumps and the very hungry windlasses.
But we are also seeing LED lighting which is very power efficient and so we need not go the route of being high power users. There is a balance to be found and you can use the engine while underway EVEN when sailing for an hour or two to juice up. The goal should be to limit the need for energy by ingenious means and conservation. And really we need to be trying to burn LESS full if we can. And we can. If you rely on a genset it's not a good place to be, I would think.
|
|
|
22-12-2008, 16:09
|
#56
|
Registered User
Join Date: May 2006
Location: Slidell, Louisiana, USA
Boat: William Atkin Cutter, 35'
Posts: 150
|
You are exactly right Chuck. We enjoy tradition in cruising and have no desire for many of the extras some call esentials. Taking along many things, which are found at home, blurs the difference between land and sea to us. Mind as well be a dirt dweller.
Of course we like tent camping and the like, so we are in the 1%, I guess. We are proud of that, and find a need to be as simple as possible, and to rely on the basics as it brings us as close to nature as possible while being as safe as possible.
The book is still a great read, it even kinda makes me feel opulent. To each his own. I bet we could still enjoy a cold one should we run across each other out there. Heres hoping we do!
Merry Christmas to all!
__________________
"Love My Country, Fear My Government"
|
|
|
22-12-2008, 16:18
|
#57
|
Registered User
Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,619
|
Looking forward to it
|
|
|
22-12-2008, 16:43
|
#58
|
Registered User
Join Date: Aug 2006
Location: Skagit City, WA
Posts: 25,744
|
DEFJEF, my experience was very similar to yours in the carribean. I had the diesel engine and a wind gen. I'm not real miserly with power, but dont use any more than I have to either. The wind gen kept fairly busy in the afternoon, but not every day, I generally ran the engine an hour a day (125Amp Alternater with 3 step charger) and just lived with the semi cold refrigerator some days. I might do a quick charge also once a day to get the first 20 min's of high rate chargeing. Especially if we just loaded the fridge.
|
|
|
22-12-2008, 17:54
|
#59
|
Registered User
Join Date: Oct 2007
Location: Lakewood Ranch, FLORIDA
Boat: Alden 50, Sarasota, Florida
Posts: 3,609
|
Quote:
Originally Posted by Fishspearit
And if you're contemplating how to keep your batteries charged when you go cruising, I would recommend solar as a better alternative than a gas gen.
|
The realities of solar power as a replacement for a H or any other genset escapes me. As you sound as though you've successfully done so, please tell me what I'm missing.
Recognizing everyone's electrical demands differ, generalizations are usually questionable so if you can base your comments on my needs, I'd appreciate it:
separate refrig and freezer, each drawing 60 amps/day avg
TV, DVD, VCR, lights, misc DC daily needs = 30 amps/day,
inverter powered AC needs incl. coffee maker, toaster, computer, etc = 40 amps/day,
non-inverter demands (those exceeding a reasonably sized inverter) incl A/C, water heater, etc.
Regardless of the last demands, I can't make the math work and when the last demands are included (we don't equate cruising with camping), I don't see how solar can be an alternative unless we drastically change our lifestyle which isn't going to happen.
|
|
|
22-12-2008, 20:28
|
#60
|
Registered User
Join Date: Oct 2007
Location: Lakewood Ranch, FLORIDA
Boat: Alden 50, Sarasota, Florida
Posts: 3,609
|
Fishspearit
when checking back to this discussion to see if you had responded to my previous post, I noticed you apparently deleted your post from which I took the above quote - shall I infer from that you recant the intent of your statement?
|
|
|
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|
|
|
|