Maris Pearl Update
This week, Old Tacoma Marine Inc finally installed the Maris Pearl’s jacket-water cooler. It wasn’t quite as smooth a process as I’d liked; after I put it in the first time, I had to pull it out and turn it around. Some of the pipe runs that I welded will need to be modified later, but it is in place and holding the jacket-water just fine.
This job is just about over, but it looks like the owner has plenty more for me to do on the Pearl before taking the boat up to Ketchikan in a few weeks.
Big Swan Drainage Problems
We got a call this week from the Big Swan Drainage & Levee District in Winchester, Illinois about their 400 horsepower Atlas-Imperial diesel. This engine is still coupled to a pump and used to move rain water from a ditch over the levee and into the river. This is one of my favorite engines because it’s still doing exactly what the district bought it to do more than fifty years ago, and they’re invested in keeping it running.
The Big Swan Drainage’s engineer called because he thinks that one of the cylinders isn’t firing, as it’s running cold, making hissing noises, and the exhaust valve cage is smoking a little. He asked me about what it would take to install a new cylinder. I said “Whoa, wait a minute!” Replacing an entire cylinder is the very last step for a problem like this – it’s a little like saying that because you have a cough and a fever you need a lung transplant. There are so many different little problems that could lead to an engine making weird noises, smoke, and giving low temperature readings that it’s best to work through symptom by symptom to fix problems and rule out causes.
The very first step is to double- and triple-check all the readings, using the built-in pyrometer and a hand-held infrared meter to determine the actual exhaust temperature. It can also be really useful to just put your hand on the exhaust manifold elbows, too. Using these different sources of information about the exhaust temperature is important to nail down exactly what the cylinder is doing.
I know of one guy who noticed a really cold temperature on the number six cylinder’s pyrometer during a routine check, so he boosted the amount of fuel going into the cylinder. It takes a while for any adjustments to make a significant change in engine temperature, so he went back up to the bridge until it was time for the next check. When he got to the engine room, number six cylinder was belching out smoke. He limped in to port and called a mechanic to come take a look at it as soon as he could. The mechanic found that the cylinder head was cracked – the increased fuel had increased the heat in the cylinder and expanded the casting enough to crack. While messing around with the cylinder head, figuring out how to fix it (it is not easy), the mechanic found the pyrometer wire laying slack behind the engine, unattached to the cylinder. The low temperature reading that led to the fuel adjustment was because the pyrometer wasn’t hooked up.
If the exhaust temperature on the Big Swan engine really is too low, then there’s still several more things to rule out before replacing a cylinder. I’ve found that it’s not very common for a cylinder to suddenly not get enough air or compression and fire incorrectly, but it’s very common for it to suddenly not get enough fuel. The next step is to check the fuel system, starting with the adjusting nut at the top of the fuel injector. This should be moved in very small increments, with the original position marked with a paint pen. If there’s still a problem, then I’d service or replace the injector. Once I was really sure that the cylinder was getting fuel and air, I might consider compression issues.
Since the Big Swan engineer also mentioned a leaky valve cage (which could be caused by a wrinkled copper gasket; easy to replace), I think that systematic testing like this will identify the problem before he gets to the “replace the cylinder” step. I hope it’s an easy fix; it’s a neat engine and I want it to keep running with minimum fuss for a long time.
Starting problems with the Oswell Foss
Later in the week, Captain Jim called us from the retired tugboat Oswell Foss about start valve problems on its G-series Enterprise diesel engine. I’m planning a trip to the San Juan Islands in a few weeks anyway, so I’ll look at the controls and air starts then. The symptoms he listed include air bleeding down fairly quickly if the handle is not in just the right spot, when earlier the handle had a little more forgiveness.
Field trip at the Northwest Marine Propulsion Museum
I finished off the week with coffee at the Northwest Marine Propulsion Museum next to Ewing Street Mooring. I thought Dan, Mike, and I would just talk shop, but it turned into an event. About eight members of the Puget Sounders chapter of the Antique Outboard Motor Club Inc showed up to take a look at old engines. Harold from the club told stories of working for Washington Iron Works for many years, which was quite a treat. We also ran the museum’s three-cylinder Atlas-Imperial diesel and talked shop for about an hour. It was a nice way to relax a little before heading back to the Pearl.
