For the most part, car engines are pretty conservative things—the vast majority of the cars you see and drive use one of a handful of basic engine designs and layouts. That’s why unusual engine designs—air-cooling, rotaries, radials, whatever—are so fascinating—they’re a working, revving reminder that there’s all kinds of interesting ways to solve the same problems. Of course, there’s degrees of interesting, and when it comes to new and novel ways of turning petroleum into noise and motion, the engines made by Trojan have to be the most interesting ever mass-produced. And by interesting, I mean really, really weird.
Trojan was a British carmaker from 1914 to 1965, though in the 1960s they were mostly just building Heinkel Isetta-like microcars under license. They were always a company that specialized in the low-end of the market, making simple and highly affordable—yet rugged—cars for farmers and workers and people with more practicality than money.
The era I want to talk about most is between the 1920s and 1930s, when Trojan was building cheap cars to compete with the Ford Model T. The first of these cars, sexily named the Trojan Utility Car, was deeply unusual all the way around.
Priced cheap, and then even cheaper to compete with the Model T, the Utility Car had a sort of boat-like tray instead of a normal chassis, and the whole drivetrain was placed flat and low in this tray, with the seats and body and everything else plopped on top.
It looked like a fairly conventional car, but the front hood area was mostly empty. It wasn’t exactly quick, with a top speed under 40 mph, and most were sold with solid rubber tires, because they were tougher, longer lasting, and couldn’t go flat. Soft suspension springs compensated for the lack of a cushion of air, though if you really wanted to, you could get one with pneumatic tires, though it’s said the Trojan salesmen would try to talk you out of such a frivolous move.
What are you, a sultan, that you need to drive around on a cushion of air?
The Trojan was so cheap that the company did some math and found that, over 200 miles, driving a Trojan was cheaper than what you’d pay in shoe leather and socks. Meaning, it was cheaper than walking, a result they gleefully touted in their ads:
Let’s not get off track, though. Sure, the Trojan was cheap as dirt, but it’s the weird-ass 11 horsepower engine they used that I want to really tell you about. It was a two-stroke, which, sure, is unusual by today’s standards, but back in the day, not that unusual for a very cheap car. It was four-cylinders, displacing either 1527cc or 1488cc, again, pretty unsurprising sizes for a small car four-banger.
No, what made this engine weird was the whole fundamental layout: it wasn’t an inline-four, or a flat-four, or even an uncommon V4. It was, um, a 2x2, I guess you could call it. It was a square block, with the four cylinders arranged in a two-by-two grid. You know, like how absolutely no other cars do it.
Each pair of cylinders shared a combustion chamber, with a common spark plug, so it was really like an inline-twin with two pistons per cylinder, sort of.
What’s even weirder is for this to work, each pair of pistons had to share a common connecting rod, but since there were two pistons, that connecting rod looked like an elongated ‘V’:
In case that’s not weird enough, those siamesed connecting rods were designed to bend and flex as the pistons moved up and down inside the cylinder, and that was absolutely fine. In fact, it’d be impossible to make this work if the connecting rods didn’t bend. The engine never rev’d past around 1500 rpm, and the rod was made of springy metal, so it just sort of worked.
Also weird was that the front hood, unencumbered by an engine, did have some things crammed in there, some expected, like the steering column and fuel tank, and at least one thing I wouldn’t expect: the carburetor.
I can’t think of any other engine where the carb is located at the other end of the car than the rest of the engine. It seems insane, but I believe it was done because the fuel system was gravity fed, and there was no fuel pump. I think that sort of makes sense?
Being a two-stroke, there was no valve train as such, with each piston in the cylinder being responsible for opening and closing either the exhaust or intake valve. This setup, with one piston for each valve instead of one piston handling both valves as in a conventional single-piston-per-cylinder two stroke, actually seems to have provided for better flow and scavenging inside the cylinder.
Thanks to arcane British tax laws that based everything on the cylinder bore and not stroke, the engines also ended up being very undersquare, with long strokes and narrow bores, which necessitated weird looking log-shaped pistons.
As weird and underpowered as this engine design was, it absolutely did work, and it was remarkably durable, with only seven moving parts. In 1929, Trojan moved the engine to the rear and gave it more power—capable of up to a screaming 45 mph—and called the new car the Trojan RE, for Rear Engine.
The RE looked a bit more refined, but was really the same, strange formula, with the weird engine tucked away in a bustle at the rear.
Trojan even tried to take their formula more upscale, with a stylish concept car they called the Mastra. It seems two of these—likely just mockups—were built to be shown in 1935.
These were said to be six-cylinder cars (well, six piston), presumably with a 3x2 layout and still using Trojan’s unusual engine designs.
Diagrams of the chassis looks very similar to the RE, simple but clever. In this picture I think I’m counting three spark plug wires, suggesting that yes, they planned on a six-piston, three connected double-cylinder configuration.
Despite some pretty drawings, it doesn’t appear that Trojan’s attempt to challenge Rover and Austin for the middle and upper chunks of the market went anywhere, and Trojan got out of passenger car production around 1937.
They did keep on using their weird 2x2 engine in delivery vans, though, and after a break during WWII when they built bomb racks and parachute containers, they kept on with it after the war, finally retiring the strange engine design in 1952.
I’m pretty sure there’s never been another mass-produced automobile since them to use an engine like this, and I’m going to go out on a limb and say there never will be.
So, with that in mind, raise a glass of 20W-50 or whale oil or whatever the hell this bizarre engine liked to mix with its petrol, and give a toast to Trojan, a true engineering weirdo.