The Venerable 4.108

Anna's Perkins 4.108 diesel engine
 visits the shop for a new, rear oil seal.

THE TIME HAD COME to resolve the rear oil seal leak, in our twenty-seven year old Perkins 4.108 diesel. Our friend. Through thick and thin. The Perkins has proved itself over and over again, a trusty workhorse. Happy to push Anna along when need be, through calms, heavy opposing currents, or simply to get from point A to point B, when timing is critical and sailing conditions, marginal.

The rear oil seal on a Perkins 4.108 is old technology. Basically, a two-part piece of asbestos-impregnated rope, stuffed into two separate, grooved slots which, when joined together, form a sealed ring around the drive shaft. And it is this primitive rope seal that is responsible for keeping the engine oil in the crankcase, and not allowing it to leak out into the bilge, where it does absolutely nothing useful. The Perkins series of diesel engines were developed, in England, back in the sixties. By today's standards they are dated and crude. But these tough, old workhorses were wildly popular, worldwide, for decades, serving the agricultural, mining and heavy-machinery industries. Later, in the seventies and eighties, the Perkins 4.108 was adopted by the marine industry. And they remained popular, with a well-established dealer and parts distribution network around the globe. Commercial fishermen relied on these workhorses until the early nineties, when Perkins quit production on the 4.108 line. Today, more sophisticated, cleaner diesel-engine technology has taken the place of the older diesels, like the 4.108. Never the less, the Perkins engines were very forgiving, nearly indestructible machines; as long as they were topped off with oil. They love their oil. I don't think that the construction of today's, cleaner, more efficient engines, are as rugged as the old diesel technology. And in the harsh realm of the marine environment, rugged and forgiving are true virtues. And so we hesitate to make the transition to the 21st century, and re-power with a Yanmar, or some other such beast, as long as we can keep finding the critical spare parts for our venerable Perkins 4.108. It has the chops to take us anywhere we need to go. So why mess with proven technology?

The weak point of the 4.108 is the design of the rear oil seal. It is fine for the first few thousand hours of engine time but gradually, slowly, it would begin to leak oil. And after a while, the leak would get worse and it would eventually leak so much oil that it was like changing the oil twice every hundred hours of engine time. We were losing one quart of oil, through the rear oil seal, and into the bilge, every eighteen hours.  Ideally you shouldn't need to add more than, say, a half quart between oil changes, that is, every hundred hours or so. So we were due. It was time to replace the rear oil seal. Again. On an old Perkins, it's simply something that needs attention about every 3,000 engine hours, give or take. Or so it seems, at least to us. This is our second time doing this - both times after 3,000 engine hours. And while the Perkins is nearly indestructible, if it loses all its oil, while underway, it's going to quit. And of course, if it's going to quit, it will inevitably do so at the worst possible time. So just change the seal - not as easy as it sounds.

The rear oil seal is still available from Perkins, even though they stopped production of the 4.108 about twenty years ago. It's a five dollar part, and that's the good news. The bad news is that to get to where the part resides, the engine must be pulled. And to pull the engine on a small sailboat, without a dedicated engine room...well, let's just say that it gets involved.

The usual things must be done, in any engine removal: the electrical connections and plumbing fittings must be disconnected, and a hoist is rigged for lifting the engine. And that is where the similarity ends, in the world of engine removal. 

On a small boat, like Anna, without a ballroom in which to work, and, while moored away from the convenience of a stationary dock, things are different. First of all, getting the engine out requires dismantling parts of the engine before it is even pulled, parts that wouldn't clear the companionway opening; parts such as the transmission, starter motor, and heat exchanger. Some of which are heavy, awkward objects with less than ideal access. After these parts are removed (with a lot of sweat and cursing) the job of rigging a come-along or chain hoisting block, to the mainsail boom comes next. This required unfastening and removing our recently installed hard, aluminum dodger, which sits directly over the companionway and therefore, directly over the location of the engine that must be pulled straight up, and swung, very carefully into the cockpit. To make matters somewhat worse, this maneuver must be carried out between wave sets and wake, which tend to roll or rock the boat, generating a pendulum effect. A pendulum with a four-hundred pound weight, swinging freely within a tight space, without wrecking the interior of the boat, or losing a finger in the process, is something to behold.

Anna is moored off of the western entrance (Pacific Ocean side)
to the Panama Canal, while her engine is pulled. Vessel traffic
through the Canal can kick up a wake at times and make
hoisting the engine a matter of good timing.

But we wrangled our friend up through the companionway and into the cockpit without incident. The next step was to get towed over to the commercial dock where we would then lift the engine, chain-block still rigged and attached to the boom, up and over the rail of the boat and set it down onto the dock, at high tide, when the gangway was level, for the four very strong dock men who would then lift the engine onto a cart, and wheel it slightly uphill, to the parking lot where a jeep was waiting to haul the engine to a shop, for disassembly and replacement of the five dollar seal. Anna would then get a tow back out to the anchorage and remain there until the engine was ready to be reinstalled. Then the whole process would then be reversed, about a week later, if all went reasonably well. 

And this is why the rear oil seal, on the Perkins 4.108, is a bear. But other than that, the engine is a marvel of low tech. A reliable, forgiving, smooth, oil-loving beast. A machine that boldly lives up to it's rugged reputation, and to its appetite for oil. A good friend that you can count on when you need it. A diesel machine that loves to keep humming under a load. Seemingly, the harder you push it, the more it likes it - albeit, today, with the aid of a few additives to keep its joints lubed. Older, heavy-duty diesel motors were built in a time when fuel with a high content of sulphur (used for lubrication of internal engine parts) could be found in diesel fuels at the pumps. Not anymore. Today's modern diesel motors use fuel which is rated for the way engines are now built - that is, designed to tolerate the low-sulphur content of today's fuels. We use a sulphur additive now, to simulate the days when diesel engines were built with high sulphur content in mind, to lubricate the internal parts of the motor and diesel injectors. 

The venerable Perkins 4.108. A part of history, and an engine worthy of rebuilding.

Panama Canal locks gates, installed
 in 1914 and still in operation today.

And while speaking of old, rugged technology...we had been moored - while the engine work was underway - at the west entrance to the Panama Canal, off of red buoy 14B, just to the west of the Bridge of the Americas, and the entrance to the Miraflores Locks on the Pacific side. Which, by the way, was completed in 1914. The original, enormous flood gates were operated by hydraulic arms. And ninety-nine years later, these same gates are still in operation. Another world-class example of low tech that works. In 2014, on the 100-year anniversary of the opening of the Canal a new, third set of locks will be completed, allowing for the transit of longer, wider ships. 

The Miraflores Locks, Panama Canal, circa 1914.

The use of more efficient rolling gates will facilitate the maintenance. The newer technology will utilize water neutralization basins requiring less water than the current locks system, thus saving 60% of the water actually used. It is said, that if the rains stopped in Panama, the Canal would be non functional. That every ship that transits the Canal uses over a million gallons of water. So, new technology is essential to handle the capacity, which is expected to double, to handle the increasing demand of worldwide trade. The new Panama Canal locks, which will run parallel to the original locks will be 427 meters long and 55 meters wide, the size of four football fields, to accommodate the new class of ginormous ocean-going vessels: 1,200 feet in length overall, with a beam of 160 feet. 

Cargo ship Bellavia anchored near Anna,
awaiting transit through the Canal.

A conservative estimate would have one of these floating behemoths carrying upward of 2,000 containers. One ship's worth of containers, if you can imagine a train made up of all 2,000 containers, would stretch for sixteen miles. That's a lot of stuff. And annually, the Panama Canal is transited by more than 14,000 vessels. The new, third set of mega-locks will effectively double the current cargo capacity - it will radically alter world trade.

The entrance to the Panama Canal is an incredibly interesting place to remove your engine, by the way. For the time that it took us to complete the project we were just a few feet away from the buoyed channel leading into the Miraflores Locks. Every sort of enormous vessel passed by us, either en route eastbound, or westbound, moving from the Atlantic to the Pacific, or vice versa. 

Warships have transited the Canal since the early 1900's.

Warships, cargo container ships, grain ships, LPG and oil tankers, coast guard vessels from around the world. The Canal is open for business twenty-four hours a day, all year. Amazingly, we could hardly feel the wake or hear the big guys as they slipped by, just a few boat lengths away. The loud, unmufflered vessels that kicked up the wake, as they flew past us, were the pilot boats and launches and tugs, all of which provide support for Canal vessel traffic.

Japanese destroyer slips past Anna,
on its way through the locks, eastbound.

In two-and-a-half weeks, the engine was back in. The remarkable disarray, of a small boat with its interior and exterior in complete disharmony, while the work proceeded, is now over with. And happily, after our initial sea trials, there appear to be no significant oil leaks, just the typical, infamous Perkins splatter - its character, so to speak. We've put on thirty engine hours now, since the engine was perched back atop its motor mounts, and it runs smoothly, reliably, and for now, even cleanly. In essence, better than ever. Not something we're quite used to yet. 

During the inspection of the engine, and its component parts, we discovered a small fracture in the wet exhaust elbow. It was leaking saltwater. We stripped it apart and had it sandblasted and found a very small hairline crack near a weld. And so we had it cleaned up and re-welded at a machine shop that has been doing business in Panama for close to 80 years. Once again, old machines were at work, machines that had been there from day one were snipping and heating and grinding and bending and drilling and welding. The business was probably started after the Canal put Panama on the map. The owner was about eighty years old and still working, hands-on. Both machining and overseeing all of the shop projects. The business passed down from one generation to the next. He carefully inspected our little project, nodded his head, smiled, and said bueno.

Bringing up the rear, this Japanese warship flies
 its traditional maritime flag - the rising sun with rays.

We also took the opportunity, while the engine was out, to clean and repaint the bilge area beneath where the engine sits. Impossible to get to otherwise. We also had the starter motor refurbished. Nothing was wrong with it, but since it was out anyway... preventative maintenance. The saltwater heat exchanger, which we expected to be corroded and clogged was mysteriously, perfectly clean, so we left it alone. We took the four diesel injectors, which once again, had given us no problems, to a diesel injector shop in Panama City for cleaning and inspection. All four injectors sprayed a perfectly normal pattern and confirmed that they were in perfect condition. The Perkins shop manual recommends inspecting the injectors after every 400 engine hours. This, in retrospect, seemed excessive. We had removed them after 2,950 engine hours, and no problems were found. There was a small vibration that got our attention, during the last couple months or so - subtle changes in the sound and vibration of the drive train and engine are easy to hear and feel. As it turned out, the bolts on the drive shaft coupler were loose - one had actually fallen off, and three were able to be removed by hand with no wrench. Not what you want to see. Basically, the coupler was hanging on by a thread. When we reinstalled the coupler, we swapped out the coarse-threaded bolts (previously installed without lock washers) with fine-threaded bolts and lock washers, in hopes of eliminating, or at least minimizing the negative effects of vibration at sea. A working engine without a coupled drive train will get you nowhere fast. Our future scheduled maintenance will include checking all the key nuts and bolts and torquing them, if needed.

All in all we're very happy with the way the engine work turned out, despite the challenge of removal and re-installation, while at anchor. We are currently finishing up some other long overdue boat projects: sail repair and some canvas replacement work here, in Panama City, and then get underway, once again, to spend some time out at the Perlas Islands. The clean, crystal clear waters around the archipelago will give us a good excuse to swim around the hull, scrub the bottom and scrape the barnacles off the prop; more enjoyable than it actually sounds.

With engine work completed, Anna is on her way, once again,
heading westbound, out of the Canal entrance channel,
 exchanging greetings with the passing Japanese fleet.

Two days ago, we were anchored out adjacent to the ever-dynamic Panama City skyline. The dramatic thunder clouds rolled in from the coastal mountain ranges and the sky quickly darkened, charcoal gray. Underneath the clouds, the light-colored buildings glowed and shimmered, and the glass facades of the waterfront office towers reflected the nuances of the towering, threatening cumulonimbus. And as dusk approached, a spectrum of scintillating neon flickered to life and illuminated the tall silhouettes of the modern cityscape, while lightning flashed and illuminated the sky aloft. On the water, large ships twinkled while anchored out in the bay, awaiting their turn to enter the locks. They surrounded Anna and provided a modicum of protection against the southwest swell, which rolls in from the open ocean, one hundred nautical miles to the south. 

It blew 35 knots in the anchorage, overnight, but quickly gave way to dead calm, full stop. You just never really know how the weather will play out here. The forecasts are extraordinarily unreliable. We prepare for the worst and hope for the best. And you take what you're dealt.

The next day we picked up the anchor and sailed to the south and east, for Islas Las Perlas, forty nautical miles distant. The day began calm and sunny. Then the skies revealed building, dark-bottomed cumulus. Ten miles from the Perlas the waves began to grow as the wind off the starboard bow picked up and the rain squalls approached from the east. Tremendous thundering and rapid lightning flashes told us that we were close to the convection zone. It poured for a few minutes and then quickly settled down. The seas flattened out and the sky cleared as we made our final approach to the pass that would lead us into the protection of the archipelago, and our next anchorage off of Mogo Mogo.