Dating to 1816, the Stirling design offered a safe, steady source of power. But by the turn of the century, the hot-air engine’s days were numbered.
“I’m guessing there were 30,000 to 40,000 built originally,” says collector Steve Gray, who lives in California. “Actually, for a short time, say 1880 to 1900, they were fairly popular. By 1900, though, gas engines were becoming more popular because they had a lot more horsepower.”
Steve’s engine collection includes a rare Stirling cycle, Rider-Ericsson hot-air pumping engine dating from about 1895. Designed strictly to pump water, the engine was built to be placed next to a well or a cistern with the pump suction pipe hanging down into the water. During operation, the water the engine is pumping is also used to cool the engine: Before water is discharged from the engine, it passes through a water jacket at the upper end of the cylinder.
“The Rider-Ericsson had very little usable horsepower,” Steve says. “As I understand it, they were originally designed to compete against the steam engine, but it took an immense engine to produce usable horsepower.”
His Rider-Ericsson (made in New York; serial number 12704) has a 6-inch bore, 3-inch stroke, and generates approximately one-eighth to one-quarter horsepower at 100 rpm. The engine weighs about 625 pounds.
Steve was visiting a collector friend of his father’s, trading engines, when he saw a curve spoke flywheel in a corner of the garage. He didn’t know much about Stirling cycle engines at the time, but he knew enough – even as a novice collector – to know he was looking at something special.
“This was in 1993 or ’94, but I knew enough by then to know that a curve spoke flywheel was an early engine, pre-1900,” he says. “He told me what it was, and I was familiar with the name, but I’d never seen a full-size, original engine: I’d only seen models.”
A deal was struck, and Steve left with the Ericsson – complete, but in pieces.
The first step in restoration was research. “I did manage to find, through Starbolt, a reprint of a book published by Rider-Ericsson. It showed the engine in different sizes,” he says. “I spent some time studying that, doing some research. I really wanted to get it back to original. It took a little time.
“Somebody down the line had spray painted it black, just to preserve it. I had to figure out how to put it together, but it went together pretty well.”
One of the biggest challenges? Much of the lining for the firebox was missing.
“Each brick in the box was numbered,” he says. “They fit together like the pieces of a jigsaw puzzle. But half of them were gone.”
The firebox consists of two pieces, so Steve made a couple of molds.
“I made wood patterns to fit each half, made a batch of fire clay (actually, several batches, learning by trial and error), and poured a liner for each half,” he explains. So far, it’s worked. “It’s held up for five years,” he says.
The transfer piston also presented a problem. The Rider-Ericsson has two pistons in one cylinder. One, though, was rusted and gone. “We have a good sheet metal guy in this area,” Steve says. “He formed a new shell for the piston, using 16 gauge sheet metal, and I heli-arced it together. It’s just as good as the original.”
Other than the piston and the firebox, the rest of the restoration was pretty basic, he says: “The engine itself is simple enough. It’s pretty straightforward, how it went together.”
More than 100 years after it was manufactured, Steve’s Rider-Ericsson “runs pretty well,” he says.
“The biggest problem I have with it is that I get to talking to people at shows, and I let the fire go out,” he says. “It’s very temperature dependent: It’s got to have a fire going under it.”
Steve’s is set up with a wood burner, although the original stove would burn wood or coal. To keep the engine running steadily, he needs to add a piece of wood – generally he uses oak – every 20 minutes.
One great engine, of course, is never enough. But Steve’s second Rider-Ericsson takes a different course: It’s a fully operational 1/3-scale model of his big Rider-Ericsson.
“It’s kind of neat to have a little guy that can sit next to the full-size engine,” he says.
The model, just recently completed, has a 2-inch bore and 1-inch stroke, and is 16 inches tall at the top of the flywheel. The kit engine was composed mainly of aluminum castings of the major components. All the brass, bronze and steel parts were made from stock material. The model is constructed and operates exactly like the full-size engine, including the burner. More ornate legs on the model are the only difference. Propane is used to fuel the model.
“I’d had the kit for a long time,” Steve says. “Basically the first Stirling engine I’d ever seen was that model.”
Building the model – the second one he’d done – was not exactly a day at the beach.
“You have to do every bit of machine work that would have been done by the original manufacturer,” he says. “It’s a real education. I’m not a machinist per se; I just learned what I know from watching my dad.”
For Steve, model building has its attractions.
“I don’t think I’ll have models as a mainstay,” Steve says, “but as I get older, they’re a lot nicer to move around than full-size engines.”
Still, there’s always a wish list.
“I’ve only seen two or three other Rider-Ericssons,” he says. One was simply too large to consider buying.
“But if I find a choice 5-inch – it’s real small, about two-thirds the size of mine, I’d get that,” he says. “But they’re real hard to come by, especially out here.”
Steve’s interest in old engines dates to his high school days. He didn’t begin collecting and restoring until 1991, though, when he got his first engine at a swap meet.
“It’s been a lot of fun,” he says. “I’ve learned a lot of history along the way. I got into it because of the machinery, and I’ve loved the machine work, but there’s so much history with all of it, and I’ve really enjoyed that.”
His collection is an eclectic one: 2-cycle engines (Petter, Elgin, Fairmont and Maytags); 4-cycle engines (Stover, Associated, Waterloo Boy and Empire, to name a few); 4-cycle “throttled” (mostly Fairbanks-Morse); 8-cycle (an Aermotor); and a couple of “specials” (a Kinner “Busy Bee” and an Atlas Scraper Co. Twin).
Currently, he’s most interested in diesels.
“I seem to be becoming a diesel fanatic,” Steve says. “I’ve just picked up my third one. They’re really no different than a gas engine, but they have a mystique. ... I’m still looking for a nice horizontal hopper-cooled, but they’re hard to get in California.”
Still, when it comes to picking favorites, the Rider-Ericsson remains high on Steve’s list. The hot-air engine, he says, never fails to draw a crowd at shows.
“People look are it, and they’re just amazed,” he says. “I understand that: I look at it running in the driveway, and I just shake my head.” FCFor more information: E-mail Steve Gray at firstname.lastname@example.org; www.oldengineshed.com.