Simanaitis Says

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THE ENGLISH Trojan automobile had more eccentricities and as many stories as the legendary Model T Ford. Introduced in 1922, the Trojan had an engine with four cylinders arranged in a square. Its bonnet, hood to us Yanks, was a dummy, as was its clutch. Advertised as more economical than walking, the Trojan wasn’t much quicker.


1922 Trojan two-door four-seat Chummy Tourer. This and other images from “The Trojan Utility Car,” by Anthony Bird, Classic Cars in Profile Volume 4, Doubleday and Company, 1968.

In his Classic Car Profile, Anthony Bird notes that the Trojan was right up there with the Ford Model T in robustness, this despite its outright unorthodoxy. The Trojan’s engine was a four-cylinder two-stroke, having only seven moving parts and bizarre in being a “duplex” design.

Arranged in a square, each pair of cylinders shared a common combustion chamber and spark plug. Like other two-stroke engines, intake and exhaust depended upon each piston alternately covering and uncovering appropriate ports; neither intake nor exhaust valves were required.


Layout and operation of a Trojan engine. This and the following image from Opposed Piston Engines, by Martin L.S. Flint and Jean-Piere Pirault, SAE International, 2009.

Note, the Trojan’s pistons were paired, but not opposed, each pair linked by a single V-shape connecting rod. At Top Dead Center (Fig. 2), the pistons have compressed the previous charge and sucked fresh air and fuel into the crankcase through the uncovered inlet port. Ignition occurs and forces the pistons downward.

The pistons lead and lag in formation because of the single connecting rod (Fig. 3). One uncovers the transfer port bringing in the fresh charge; the other uncovers the exhaust port expelling the spent one.

Finally (Fig. 4), the paired pistons move in lead/lag unison into their compression stroke. One advantage of this duplex layout is lessening a traditional two-stroke’s behavior of tossing out some of the fresh charge with the previous exhaust.


A Trojan’s single connecting rod for its paired pistons. Fortunately it was lithe and limber.

The action of this single connecting rod is impossible without bending. As author Bird notes, “…impossible or no, the Trojan connecting rods did indeed bend at each turn of the crank and seemed to be perfectly happy to do so year after year. It is only fair to say that they were fairly thin, not highly stressed, and that crankshaft speed did not exceed 1500 rpm.”

The engine and gearbox resided transversely under the front seat, a roller chain delivering propulsion to the rear wheels. What with this compact packaging, there was no reason for a bonnet per se; the Trojan’s was merely for appearance.

As author Bird observes, “The Trojan bonnet contained the petrol tank, the carburettor, part of the steering column and a large amount of damn-all.” Notice, having the carburetor some distance from the engine didn’t help mixture preparation.


The Trojan engine, as seen from below. Its small bore and long stroke are evident.

Britain’s R.A.C. road tax was based on an engine’s bore (not its total displacement), and the Trojan’s diminutive 2.5-in. bore gave it a Taxable Rating of 11 hp. By contrast, the Ford Model T was rated at 23 hp. Here, however, Inland Revenue got its sums correct. The Model T actually produced around 22 hp; the Trojan, only 11. To its benefit, the Trojan’s power curve was astonishingly flat, with perhaps 10 hp at only 450 rpm.


Wing-Commander A.F. Scroggs, famed Trojanist, does some mud-plucking at the Fingle Bridge Hill Climb.

Like the Model T, the car’s epicyclic gearbox gave it two forward speeds. Unlike the Model T, though, the Trojan had an auxiliary clutch pedal, not necessary with this type of gearbox but a concession to fashion. Drivers learned it could be ignored.


Cross-country travel in a six-wheel Trojan, 1928

The Trojan was renowned for its durability. In 1925, for example, one made a cross-Eurasian trek from Singapore to London. The tea merchant Brookes Bond had 2000 Trojans in its fleet; for years, the RAF used them as tenders. In 1928, Trojan tested a four-wheel-drive six-wheel quasi-tracked version.


A Chummy and a hardtop Trojan compete on the Midland Car Club’s London-Edinburgh Trial, 1928.

Even into the late 1920s, pneumatic tires remained an oft-unselected option. The Trojan’s solid-rubber variety avoided punctures and were fine in the dry, but were prone to side-slip on wet stone pavé surfaces in town. With regard to this, author Bird cites a 1901 Lanchester Driver’s Manual: “But remember, whatever the state of the roads, it is bad driving to navigate your car sideways.”

Yes, but possibly also great fun. ds

© Dennis Simanaitis,, 2015


  1. R Franklin
    May 7, 2020

    I owned this car from November 1992 until mid 2016.

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