On Mon, 06 Mar 2006 21:01:33 GMT, Lew Hodgett
wrote:

Wet stacking happens when the engine system does not come up to
operating temperatures for extended periods.

This talk about not coming up to operating temperature has me mildly
confused. Isn't that what the thermostat is for? My diesels will
come up to thermostat temperature at slow idle with no load at all.

What am I missing?

Wayne.B wrote:


This talk about not coming up to operating temperature has me mildly
confused. Isn't that what the thermostat is for? My diesels will
come up to thermostat temperature at slow idle with no load at all.

What am I missing?


Don't think you are probably missing anything.

A diesel will idle at relatively low RPM.

This low RPM may not allow the engine to come up to operating
temperature(with or without a thermostat).

Result is incomplete combustion which will allow unburned fuel to glaze
onto cylinder walls.

The result of that is a very expensive repair bill.

Lew

Have a search at www.boatdiesel.com, this has been covered many times.
There is also an article on this:
http://boatdiesel.com/Articles/Artic...ion.cfm&Y=2004

You will need to join the web site to read this one, ($25/yr, and
worth it every once and a while).

I to have a 6B in a trawler and have am OK with slow operation. My
normal cruise is 1400 rpm (6.7kn). Key here is to get the motor to
operating temperature (Idling, even at a fast idle will not do it, you
need to run the boat) and then make sure it stays at temp.

The 6B's at times have problems with their thermostats, so watch that
and if the temp falls off, then change it out 1st thing. I had to
change out mine at 400hrs, no problems after doing so.

When we run Christmas ships I spend a few hours at a time at 1100-1200
RPM, and the temp always stays up. So, again, the key here is get up
to temp (I usually run around 1700 or so to make sure I am up to temp)
and do not worry. Based on what I have seen from people who have been
around motors with high hours, I am expecting well over 10,000hrs on
my motor. Turbo included

-al-

On Sun, 05 Mar 2006 14:17:33 -0800, Tamaroak
wrote:

Let's say you just took delivery of a used 27000# trawler powered by a
single Cummins turbo-diesel 220, model 6BT5.9M. You want to get maximum
miles per gallon out of it and know the slower you go, the better, but
these motors don't like to go slow for a number of reasons. Of course,
you also want it to last forever because it might cost $10,000 to
rebuild it, not including pulling it out and putting it back in..

What would you consider a minimum cruising speed, with an occasional
shot at 2000 rpm just to clean things out?

Capt. Jeff

On Sun, 05 Mar 2006 22:59:31 -0500, Larry wrote:

Larry wrote in
:

I could see it would carbon up if you just ran the engines in an
unloaded condition in neutral for long periods of time....

Thinking about this, I cannot help but think about those engines in the
big trucks that are left idling for 8 hours, virtually unloaded, while
the driver is sleeping in his sleeper at the truck stop. I suppose he
burns off all the deposits when he drives off down the interstate in the
morning.

Obviously, 8 hours of idling while sleeping, followed by 8 hours of 80
mph under load, followed by 8 hours of idling, again, isn't hurting
Cummins engines much. Hell, they don't overhaul them in the real world
away from the service manual until the clock says 400,000 to 500,000
miles...or more.

What about my diesel cars that hardly ever leave the city? I've never
seen this phenomenon while sitting in the traffic for hours on end,
idling along to the next traffic light.....??

Maybe it isn't as serious as it's imagined.....?? My 73 220D was
overhauled at 300K after 28 years on the road. Its exhaust always
looked black and oily, especially if you brushed your pants against the
pipe getting the load out of the trunk. I saved a piston and the valves
from the overhaul junk pile. There wasn't any kind of hard coked
deposits anywhere you couldn't wipe off with a shop rag....

Automotive/truck diesels are different, designed to run at light load for
extended periods. Marine/industrial diesels are designed to run at high
load all the time, like a truck pulling a full load over an endless
mountain pass. Of course there's some crossover, but for the most part
these are different types of engines.

Matt O.

"Matt O'Toole" wrote in message
news
On Sun, 05 Mar 2006 22:59:31 -0500, Larry wrote:
Automotive/truck diesels are different, designed to run at light load for
extended periods. Marine/industrial diesels are designed to run at high
load all the time, like a truck pulling a full load over an endless
mountain pass. Of course there's some crossover, but for the most part
these are different types of engines.


I suspect that many here have visited this site; for those who haven't, take
a look at this for one person's opinions on diesel power for boats (and many
other subjects).
http://www.yachtsurvey.com/GasNdiesel.htm

That's probably why we didn't have any problem with the
route vehicles. The 5-10 minute drive to the next stop
made sure that the engine stayed up at operating temp.

Don W.

Lew Hodgett wrote:
Wayne.B wrote:


This talk about not coming up to operating temperature has me mildly
confused. Isn't that what the thermostat is for? My diesels will
come up to thermostat temperature at slow idle with no load at all.

What am I missing?


Don't think you are probably missing anything.

A diesel will idle at relatively low RPM.

This low RPM may not allow the engine to come up to operating
temperature(with or without a thermostat).

Result is incomplete combustion which will allow unburned fuel to glaze
onto cylinder walls.

The result of that is a very expensive repair bill.

Lew

On Tue, 7 Mar 2006 12:50:33 -0500, "John Wentworth"
wrote:


"Matt O'Toole" wrote in message
news
On Sun, 05 Mar 2006 22:59:31 -0500, Larry wrote:
Automotive/truck diesels are different, designed to run at light load for
extended periods. Marine/industrial diesels are designed to run at high
load all the time, like a truck pulling a full load over an endless
mountain pass. Of course there's some crossover, but for the most part
these are different types of engines.


I suspect that many here have visited this site; for those who haven't, take
a look at this for one person's opinions on diesel power for boats (and many
other subjects).
http://www.yachtsurvey.com/GasNdiesel.htm



Very informative. Thanks.
--
'Til next time,

John H

******************************************
***** Have a Spectacular Day! *****
******************************************

In article ,
Matt O'Toole wrote:

Automotive/truck diesels are different, designed to run at light load for
extended periods. Marine/industrial diesels are designed to run at high
load all the time, like a truck pulling a full load over an endless
mountain pass. Of course there's some crossover, but for the most part
these are different types of engines.

Matt O.

I really don't know where you learned your Diesel Engineering, but
a 3408 CAT is a 3408 CAT, and it really doesn't matter if it is in a
truck, boat, or Genset. The only real difference is in the governer
and not really much difference there, either.....

Me

"Al Thomason" wrote in message
...

When we run Christmas ships I spend a few hours at a time at 1100-1200
RPM, and the temp always stays up.

Al, please excuse my ignorance,

What is a "Christmas" ship?

RCE

Matt O'Toole wrote in
news
Automotive/truck diesels are different, designed to run at light load for
extended periods. Marine/industrial diesels are designed to run at high
load all the time, like a truck pulling a full load over an endless
mountain pass. Of course there's some crossover, but for the most part
these are different types of engines.

Matt O.



Hmm...that's odd. Other than the seawater pump and heat exchanger the
Perkins 4-108 in the ketch looks exactly like the Perkins 4-108 in English
tractors! The parts even fit!