Saturday, May 21, 2016

Engine repair

The first engine repair has on  our Deere 6068TFM main engine has reared it's ugly head. Basically, the repair revolves around a fuel leak at injector number five, and after a bit of work, I think I've resolved the leak.

The way a diesel engine creates power is through high compression, which ignites fuel in the cylinder, causing the pistons to move up and down thus powering the engine. This happens via fuel being pumped at high pressure into a device called an injector, which precisely sprays fuel into the cylinder ( at crazy high pressure ). Once the fuel has been sprayed in the cylinder,  valves close, and the piston comes up compressing the fuel/ air mix so greatly that an explosion occurs. The piston is forced back down from the explosion, an exhaust valve opens pushing out the now heated air while another valve opens pulling fresh air into the cylinder. Now, the piston comes back up, and the process is repeated. Whatever fuel is not used by the injector is returned to the fuel tank at minimal pressure. Each cylinder has an injector which sit on top of the engine's cylinder head. To a person who is familiar with gasoline engines, injectors look similar to a spark plugs.

When I was in the in the Gulf inter coastal water way around Panama City with my two older kids, one of our engine room checks  found fuel leaking from the high pressure fuel line where it connects to the injector ( there's a nut on the high pressure fuel line, and another nut on the low pressure return line). Loosening and re tightening the line did not fix the leak, so a crack in the line or nut was my diagnosis of the problem, and a new high pressure line was ordered and installed.

With the new line installed and tested dock side we saw no sign of a leak so off we headed on a 230 mile passage across the Gulf of Mexico towards Venice Florida. Running the engine at a steady 1500 rpm for 35 or so hours showed no leak, and all seemed good. During the next day or so while making way to Ft. Myers at a higher RPM, a slight amount of fuel showed up around the nut causing me to loosen and re tighten the nut again thinking a slight burr or some other issue caused the seep to re appear.

All was well over the next couple of months using the boat lightly for a few day trips with no leak detected. On our 350 mile round trip to Key West, while running the RPM's up over 1700, the leak at number five showed back up. Loosening and re tightening the nut seemed to adjust the leak, but it now was obvious at this point that a bigger issue was causing this.

Back at our home port, and wanting to get this issued resolved before we head back to Key West this summer, I concluded the injector had to be bad. My thought was there must be a crack  in the pressure line on the injector itself, and for some reason, the higher rpm was causing the leak to show up. My real fear, was that if I continued to run the engine with this problem, I could cause a catastrophic failure in the cylinder wall due to improper metering of fuel. It was time to order a new injector and a seal kit.

A few days later, the new injector showed up, so here's how the install went, and what I found: The style of injector on our engine is what's called a pencil injector. The injector has an upper and lower seal on it, and is housed in a very precise bore in the cylinder head. It is held in place by a bolt that compresses some clamps that are on the injector. To remove the injector, one removes the two fuel return lines and fuel supply line. Once  the fuel return lines are removed, the fuel return "T" on top of the injector can now be rotated so you can get a socket on the retainer bolt and remove that. With the retainer bolt removed, you then can use a small lady finger type pry bar to most carefully get under the high pressure line of the injector and ever so easily break the injector loose. Once the compressed seal is loose and unseated in the bore, you can grab the injector with your hand and pull it out of the bore. The key words here are "gentle", "finesse", "easy", "slow" get the idea.

With the injector out and on my work bench, I was now able to remove the compression nut that held the return "T" in place. As I pulled the "T" off of the top of the injector , a small part of the injector fell out of the nut. With the new injector laying alongside the old one for comparison,  it was obvious that the return part of the old injector was broken which was the likely cause of this leak issue.

The new injector was easily installed in the reverse order as the removal. After warming up the engine, and running it at a higher rpm for ten minutes or so, no leak showed up.  As soon as I get some time, I'll take her out and put a heavy load on the engine to see if this was the problem.

Given the part that was broken off on the  injector, I can only conclude that the return circuit of the fuel was intermittently being messed with and this was forcing the leak to develop. All parts of the injector are accounted for, so I'm confident no pieces are in the return line. Before replacing this injector, the engine ran fine, with no hint of a miss. I say this because when I was dealing with loosening and re tightening the offending pressure line, the engine would miss, as one would expect, when the fuel line was broken free. Occasionally, I post on the trawler forum, and the other day I was up on the boat roof with a sound meter observing decibel's for a thread I was participating in, when I noticed a slight puff of black smoke coming from the dry exhaust stack while running her at 1500.  When a diesel engine is running correctly, all one should see coming from the exhaust pipe is heat. Black smoke coming out the exhaust pipe is fuel that has not been burned, and is a tell tale sign of restricted air, or an issue with how much fuel is being metered by the  injector. The amount of black smoke I saw was indeed  minuscule, but was enough to make me pause and think about it for the lasts few days. The exhaust color I was witnessing now makes sense due to the broken injector. Now, with the new injector installed, and me sitting on the roof watching the exhaust pipe while running the engine at 1500, I'm happy to report that the exhaust looks pristine.

Writing this post took longer than replacing this injector. While I hate to see a failure with only 400 hours on the engine, one has to be a realist with the fact that things due indeed break. It is a little comforting that the failure was so evident and that I was indeed replacing a part that obviously needed replacing. I'm going to order another injector so we have a spare on board as this is a not so expensive part that could literally leave you dead in the water.



Friday, April 29, 2016

Steps for the roof

Ever since we launched the boat, we've been using a short fiberglass ladder to gain access to the roof. Along with being too short, the ladder was never secured properly, and it was a matter of time before something bad was going to happen, and someone would end up hurt.

Most, if not all, of my decent tools are stored in Ohio. While I do not yet have a working shop in Florida, I do have some basic tools that I store in a shipping container, and for the time being, that shipping container is my "shop".  My multi process inverter welder along with some basic welding tools made the boat trip to Florida with me, and that's what I used to fabricate these steps. The Everlast inverter welder I have is actually a pretty nice machine being able to stick weld, TIG weld, and plasma cut. This welder is compact only weighing 60 LBS, and is easily small enough to fit in the engine room of the boat if I ever want to bring it with me on a trip. The boat is wired for 120 volt AC, and our on board, 10 KW generator is capable of producing 240 volt AC. When I want to have 240 volt AC on board, such as needing to run the welder, I simply have to change two wires in the generator and install a 50 amp pigtail to plug a 240 volt device into. When I do this re-wire, I'm disconnecting the 120 volt feed from the generator to the distribution panel, and temporarily installing a 240 volt circuit.

Working on a boat in a harbor is a tough, and there's now way around it. Things just go slower in the harbor. Our harbor has wide, fixed concrete decks, and that makes a large project like this a little more easy to get finished. The back deck of the boat became my weld shop while the concrete deck of the harbor was my cut shop. TIG welding aluminum is as finicky process and having the sheltered aft deck helped control the breeze that messed with shielding gas of  the weld process. I greatly miss my shop in Ohio, and one of the things I miss most of having a large, well equipped shop, is that when I had enough of working on something, I'd just put my stuff down and pick up where I'd left off in a day or three. Here, working on the boat in a harbor, I have to clean up everything every time I leave the boat for the day. It's a great thing keeping my work area clean, but it does add time to a project.

Like I said above, the steps are made of 6" aluminum channel, which is way over kill for this application. I could have gotten by with 4", but I wanted wide treads, and I didn't want to have to get into a much more tricky fabricating job of having to get the same wide tread using lighter material. When I built the salon and wheel house, I knew there were going to be steps of some sorts leading to the roof, I just didn't know what they'd look like. I took a guess, and welded brackets to the salon wall, and this is what I used to pin the steps to the bulkhead with. Back then, I did some guessing at future needs, and have fixtures and brackets in a few other spots on the boat.  While the steps are not the most elegant and svelte design, I can honestly say they're robust and rock solid.

Our grill is on the roof, our kayaks are on the roof, and our dinghy will reside on the roof. The roof is a place we go to often, and having a functional, solid set of steps is a huge improvement. The one compromise is the steps block easy access to our mid ship cleat which we spring off of. I have two choices regarding this cleat. When underway, I like to have all the lines off of the cleats and stowed on the fore deck rail, but the new stairs are going to alter how we treat one line. I can stow the mid ship line on the rail above the mid ship cleat, adjacent to the steps,  and not worry about it, or weld a hook to the back side of the stair tread to stow the line under the steps. Either way, with the steps pinned in place, the line will have to remain on the mid ship cleat. Or, we can stow the steps on the front of the wheel house and have easy access to the mid ship cleat. Either way, it will still be an easy deal to throw line to a line handler, and that's  not changed, it's just that we've been doing it a certain way for a couple of years now, and the new steps have changed that.

As I've said many times before, I'm glad I didn't have to give someone a price to build these steps, since they took a lot longer than what I would have guessed. While they're not ideal, I'm totally happy with how good they feel, and how much safer getting to the roof has become. With the outboard pipe rail and the trim detail of the wheel house roof, one has dual grab rails while using the steps.


Saturday, April 16, 2016

I'm back

Well, truth be told, we never left...just relocated.

My last post was regarding me working on the handrails for the lid deck. That was an important detail as it makes spending time up on the roof much safer, and makes the boat that much larger. The handrail was finished, the boat went back in the water for the season, and boat building ceased.

Boat building had pretty much ceased for the winter of 14/15, and my focus shifted to working on our house getting it ready to list for sale. Shannon was still in school finishing up her respiratory degree so I began pecking away at  a long to do list on the house. Some projects were substantial, some were not. The bottom line was I devoted about five months of steady work, and sometime about the end of May, 2015, we listed the house on one of those online " for sale by owner sites ". Three weeks after listing the house, we had an offer, and a week after that we had a deposit with a move out date agreed upon a week or so later. Fast forward a fuzz and we ended up in Cape Coral, Florida

Moving the boat to Florida began in late October of 2015, and was done by me and a friend Pat. The route to Cape Coral was as follows: The Ohio River, to the Cumberland River, to the Tennessee River, to the Tennessee Tom Bigbee River, to the Black Warrior River, to the Mobile River in to Mobile Bay, East on Gulf Coast Inter coastal water way, cross the Gulf of Mexico from Panama City to Ft. Myers Florida where we now harbor the boat at the Ft. Myers Yacht basin. The trip was about 2000 miles, and took a couple of months as we left the boat a few times to return to family.

So here I sit in Cape Coral, Florida typing this blog update and I'm still working on finishing the boat. There are a few big projects that need to be finished, and I plan on documenting these projects on the old boat build blog.