Wednesday, August 8, 2007

Work of a Craftsman

Before I went away on my motorcycle trip and returned to break my Albin engine, I was reporting on the rebuild of that engine done in the fall of 2005. I assisted my friend John Dickerson, who gratiously allowed himself to be suckered into helping me. I'm sure he realized I would soon be in over my head and was curious to play with the funky old Albin.

The other day I reviewed the serial number history of the engine and the first one really was built in 1925. Mine was built in 1967 and production ceased in 1976.

Although it is a Swedish engine, a few key components were sourced elsewhere. The Stromberg carburetor and the Bosch starter-generator came from Germany. The SEM magneto is French.

The carburetor was no longer able to provide a reliable fuel-air mixture and a replacement was not available. After a lot of searching for an alternative, I settled on the only obvious choice--a new Zenith carburetor made for the Universal Atomic 4 engine. It was even possible to buy an adjustable main jet and needle so that I could tune the Zenith to match the Albin's needs.

The only problem was that it didn't quite fit the Albin manifold. John built the two necessary adapters, one to bolt to the engine manifold and the other to attach the Stromberg's flame arrestor to the Zenith. The Zenith was designed for the Atomic 4's flame arrestor, which could not be installed in the space available on the Albin.

The manifold adapter was fairly straight-forward. Two flanges were cut, one matched the bolt pattern of the Zenith and the other matched the manifold. A short length of tubing was welded between them.

The flame arrestor adapter was less obvious, at least to me. He made it from oversized stainless tubing that he cut into three sections and then sliced lengthwise. Each section was then re-rolled to create three concentric tubes that brought the outside diameter of the Zenith's opening down to the inside diameter of the Stromberg's flame arrestor. A little TIG welding, followed by the polishing wheel, yielded an object of beauty in my eyes. (The length of the adapter was necessary to clear a bulge in the cylinder block.)

The completed unit bolted into place perfectly. In fact, one night some months later, when I was boarded by the Coast Guard while single-handing back down the Alamitos Bay channel (a story for another time), I was complimented on my flame arrestor. Had it not been there I would have been cited.

Mostly the new carburetor worked well, except...

The first problem came at the end of a test run powering to Avalon. I did initially test the reinstalled engine with some fairly short inner harbor runs. But what I wanted was a boat that would take me to Avalon, so that's what I tested for.

I reached Avalon under power with no problem at all. But as I was idling while doing the necessary mooring transaction with the harbor patrol boat, the Albin died. It started up again okay, and with throttle advanced it ran. But it died once more as I idled down the narrow passage between rows of moorings to my assigned can. I ended up making a dead-stick landing, single-handed. And got away with it!

What followed were several months of motoring tests which ended with the engine dying when I throttled back from full speed to idle, but only after a prolonged run at full speed.

Eventually I discovered that the engine was flooding at idle under those cirumstances. The reason was that the fuel pump was putting out too much fuel pressure. I had replaced the old pump, which worked, with a new one without realizing that pumps came with different pressure settings. The bodies were identical. I was only trying to forestall a future pump failure, but I violated the cardinal rule, if it ain't broke...

Somewhere along the way, I inspected my aluminum gas tank and saw that it was pitted inside and the bottom appeared dirty. So I had my fuel polished and my tank cleaned. Another rule violation.

The result thereafter was that everytime I ran the engine, the fuel pickup tube would eventually clog with debris. Old fuel tanks don't clean very well, especially if you can't open one side to clean inside around the baffles and in all the corners. But what cleaning through the filler neck does do well is loosen the gunk that it doesn't remove, so that the fuel system can suck it up.

That led to having a custom fuel tank built because no standard sized tank would fit. Actually, that was a good thing and only cost $423 at Pipeworks Fabrication, Inc., in Long Beach. The new tank is 3/16 inch 5086 aluminum, thicker and stronger than the original, and came with a fuel level sender installed and calibrated. I also was able to make it an inch taller, adding two gallons of capacity. And I had the fill neck moved the quarter-inch forward needed to correct the misalignment of the original with the cockpit sole fill plate.

It took me a number of hours running time to create and then solve the fuel problems. But the eventual result was an engine that started and ran reliably. Until last Saturday that is.

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