I have been. While I was in Florida, I read an article in a boating magazine that discussed diesel engine loads, wet stacking and cylinder washdown. The article states that most cruising sailors are ruining their diesels because we try so hard to stretch each gallon we consume. (GUILTY as charged.) So I found a few articles that deal with diesel generators and wet stacking. A diesel generator running below design RPM is just like a marine diesel being "babied" to extend the boat's cruising range.
http://www.kraftpower.com/pdfs/KPC_IS_1 ... acking.pdf
http://www.powerscity.com/message_7.html
http://www.dieselgeneratorset.us/wetsta ... torset.htm
"Wet Stacking" happen when a diesel engine operates below the rated output level the engine starts over-fuel or "wet stack". Diesel engines are designed to operate with a load and operate more efficiently in the 70 to 80% range of rated output. When a diesel engine operates for a long period of time below 40% it begins to over fuel. This happens because the injection tips begins to carbonize and disrupt the fuel spray pattern. From http://www.dieselgeneratorset.us
Also, when engines run below the designed operational temperature, the piston rings do not expand sufficiently to adequately seal the space between the pistons and the cylinder walls. This results in unburned fuel and gases escaping into the oil pan and diluting the lubricating properties of the oil, leading to premature engine wear. From http://www.kraftpower.com
Solutions for wet stacking:
The obvious solution is to always run the generator set with an electrical load that reaches the designed operational temperature of the diesel, or approximately 75% of full load. Built-up fuel deposits and carbon can be removed by running the diesel engine at the required operational temperature for several hours if wet stacking has not yet reached the level where carbon buildup can only be removed by a major engine overhaul. From http://www.kraftpower.com My emphasis added.
So anyway, I've started running my engine harder for several hours when I run it. And we've upped our cruising speed. We used to run at 4 knots but recently we've been using 5 to 5.5 knots with some sustained 15 minute periods of 6 to 6.5 knots. And I think it's working. I have been seeing some soot coming out of the exhaust at the higher rpms. Fingers crossed that I and the previous owner haven't quite killed this engine.
http://www.kraftpower.com/pdfs/KPC_IS_1 ... acking.pdf
http://www.powerscity.com/message_7.html
http://www.dieselgeneratorset.us/wetsta ... torset.htm
"Wet Stacking" happen when a diesel engine operates below the rated output level the engine starts over-fuel or "wet stack". Diesel engines are designed to operate with a load and operate more efficiently in the 70 to 80% range of rated output. When a diesel engine operates for a long period of time below 40% it begins to over fuel. This happens because the injection tips begins to carbonize and disrupt the fuel spray pattern. From http://www.dieselgeneratorset.us
Also, when engines run below the designed operational temperature, the piston rings do not expand sufficiently to adequately seal the space between the pistons and the cylinder walls. This results in unburned fuel and gases escaping into the oil pan and diluting the lubricating properties of the oil, leading to premature engine wear. From http://www.kraftpower.com
Solutions for wet stacking:
The obvious solution is to always run the generator set with an electrical load that reaches the designed operational temperature of the diesel, or approximately 75% of full load. Built-up fuel deposits and carbon can be removed by running the diesel engine at the required operational temperature for several hours if wet stacking has not yet reached the level where carbon buildup can only be removed by a major engine overhaul. From http://www.kraftpower.com My emphasis added.
So anyway, I've started running my engine harder for several hours when I run it. And we've upped our cruising speed. We used to run at 4 knots but recently we've been using 5 to 5.5 knots with some sustained 15 minute periods of 6 to 6.5 knots. And I think it's working. I have been seeing some soot coming out of the exhaust at the higher rpms. Fingers crossed that I and the previous owner haven't quite killed this engine.