Meet the A16, Our First Nordic-Style Stationary Engine Model. Should We Made It?

A hundred and thirty years ago, a farm in Denmark or Sweden ran on muscle. Water was pumped by hand, and grain waited to be threshed until a steam engine on wheels finally rolled up the lane. Then a small, tall engine with an open frame and a heavy flywheel changed rural life across the North.

This is the story of those Nordic farm engines: where they came from, what they did, and why collectors still start them up today. It’s also the story behind the Retrol A16, our first Nordic-style stationary engine model, now available to pre-order.

Before the Engine: Waiting for Steam

On a Nordic farm around 1890, mechanical power was something you borrowed. A portable steam engine, hauled from farm to farm and shared by the whole district, arrived for threshing after the harvest and then moved on. Owning one outright rarely made sense for a machine that stood idle most of the year, and for the rest of the year there was no machine at all.

1893: The Farm Engine Arrives in Denmark

In 1893, the first factory dedicated to these engines opened in Copenhagen. Its engines were single-cylinder, affordable and simple enough for a farmer or a smith to install and run on his own. Demand took off. Over the following decades, more than 250 engine factories sprang up across Denmark, many of them in small towns where they cast their own iron.

Makers borrowed each other’s ideas freely, so the engines of the period began to look strikingly alike: tall, brightly painted, trimmed in brass, with a heavy flywheel turning beside them. Many were built in what Danish makers called the “open type.” Instead of sealing the moving parts inside a housing, they left the crankshaft, connecting rod and valve gear in plain view, so an operator could see, oil and adjust everything by hand. A good mechanic could tell how an engine was running just by watching it.

The Workhorse of the Nordic Countryside

Once installed, these engines went to work everywhere:

• On farmsThey pumped water and drove threshing machines and grain grinders, often running for hours with little more than an oil can and a watchful eye.
• At windmillsMany millers installed an engine to keep the millstones turning when the wind was too weak.
• In smithies and workshopsAn engine of just a few horsepower could drive the machinery for a whole shop.
• At seaFishermen bolted them into their boats and stopped rowing home against the wind.

Hot Bulb Engines: Starting Was a Ritual

Many of these engines were hot bulb engines, and getting one going took patience. The operator heated a cast-iron bulb on the cylinder head with a blowlamp until it glowed, which could take five to ten minutes. That wait was the moment to top up the oilers and check the cooling water and fuel. Once the engine was running, the heat of combustion kept the bulb hot on its own.

They had another quirk: many could run in either direction, and if one started backward, an experienced operator knew how to bring it round to forward without stopping it.

The Other Branch: Spark-Ignited Petrol Engines

Not every Nordic farm engine needed a blowlamp. Alongside the hot bulb engines grew a lighter line of engines that lit their fuel with a spark. Around 1910, Danish workshops were already building petroleum engines with magneto ignition, and they started far more quickly than a hot bulb engine ever could.

One story from the 1920s sums it up. A Danish country mechanic built a big hot bulb engine of his own, found it too heavy and awkward to sell, and turned instead to a small, simple petrol engine of only a few horsepower that any farm could afford and run. Over time, some owners of older engines went the same way, converting them from hot bulb to spark ignition, fitting a carburetor and running them on petrol.

This is the branch the Retrol A16 comes from.

Decades of Work, Then Silence

For decades, these engines were simply part of rural life. Some kept going far longer than anyone expected. One Danish farm engine, now in a museum collection, pumped its farm’s water every day until 1973, when the farm finally got electricity.

Electricity is what ended their era. One by one, electric motors took over the pumps and threshers, and the old engines fell silent. Some were scrapped for their iron. Many more were pushed into the corner of a barn or shed and forgotten.

Are Nordic Farm Engines Still Used Today?

Hardly any still do farm work, but they never disappeared. They found a second life as a hobby. Across Denmark, Sweden and Norway, collectors track down old engines, restore them and bring them to engine rallies, just to start them up and hear that slow, steady beat again. One museum in Denmark alone keeps more than 450 stationary engines, and old engines still change hands between enthusiasts today.

And under every video of one running, someone asks the same question: where can I get one?

Why Open Engines Are So Satisfying to Watch

With an open-crank engine, nothing is hidden. You can see the piston travel, the crankshaft turn and the valves open and close, and even if you’ve never worked on an engine, you’ll quickly get a feel for what’s happening and why.

They’re a pleasure to listen to as well: the click of the valve gear, a soft hollow note as the piston returns, and the steady rhythm of intake and exhaust. And they were built to be looked at, with shaped bases, brass handles, copper pipework, flyball governors and a careful paint finish over hand-finished castings.

From the Barn to Your Bench: Meet the Retrol A16

Nordic farm engines are loved by collectors, yet working models of them are almost impossible to find. Shelves are full of American and British designs. So we built one.

The Retrol A16 takes the look of those old Nordic farm engines (the tall A-frame, the open crankcase, the brass flyball governor and the big curved-spoke flywheel) and gives it the simple, spark-ignited heart of the petrol engines that ran beside them. It isn’t a replica of any one historical engine. It’s a 16cc four-stroke gasoline engine that you can start, hear idle and watch work on your own bench.

More than half of its parts are cast from molds made just for the A16, including the flywheel, the base, the A-frame and the cylinder, the same way the originals were made. That’s what gives it the weight and presence of a real farm engine.

A Walk Through the A16, Top to Bottom

• At the top

  The flyball governor

  A polished brass flyball governor keeps the engine from running too fast. As speed rises, the weighted arms swing outward and, through a linkage to the intake cam, rein the engine back in. When it slows, the arms drop and the engine picks up again. It’s one of the oldest automatic controls in engineering, made famous by James Watt on steam engines, and it works without a single sensor or wire.

• Below the governor

  The crossbeam and valve gear

  An adjustable camshaft drives pushrods up the sides of the engine. Rocker arms on the crossbeam tip back and forth to open the valves, and coil springs snap them shut. The whole sequence happens in plain view, so you can follow the engine’s timing with your eyes.

• On the crossbeam

  The carburetor and float

  A naturally aspirated carburetor mixes gasoline and air, and a float on the crossbeam keeps the fuel level steady so the engine runs consistently.

• In the cylinder head

  CDI spark ignition

  A CDI-controlled spark plug fires the mixture on each power stroke. No blowlamp, no waiting: turn the flywheel by hand, or spin it up with an ordinary electric drill (not included).

• Beside the engine

  Water cooling

  A plunger pump circulates water between the cylinder and the water tank through copper pipes, keeping the engine at its normal running temperature, just like the cooling tanks you’d see beside an old stationary engine.

• Under the cylinder

  The A-frame and open crankcase

  The cylinder stands high on a cast A-frame, the classic support of early vertical engines. Below it, the crankcase is left open, so you can watch the crankshaft turn and the connecting rod drive the piston.

• On one side

  The curved-spoke flywheel

  A large cast flywheel with sweeping curved spokes carries the engine smoothly between power strokes, with a bare-metal rim that catches the light as it turns.

• All over

  Red or green

  Choose Scandinavian barn red, bold and bright, or classic machinery green, quiet and understated. Both come with polished brass fittings.

The Retrol A16 at a Glance

See full specs and what’s in the box

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