- FIVE-STROKE
We’ll kick things off with something you will probably see in production in the
very near future. It’s a take on the conventional four-valve engine, except that it
allows an additional combustion cycle. So, instead of the spent exhaust gases
exiting post-combustion, they are sent into another combustion chamber and
compressed for a second time before being exhausted. This second combustion
chamber is twice the bore of the first and is common between two fired high-
compression cylinders. This effectively increases the expansion ratio of the
engine without the side effects that you’d get with an impossibly long stroke. - DUKE AXIAL ENGINE
Developed right here in New Zealand, the Duke axial engine looks like something
that belongs in the front of a World War II fighter. Ditching the traditional
crankshaft, the cylinders are parallel to the main shaft, with the combustion
forces acting on a reciprocator that oscillates around the main shaft in a wave-
like motion. Similar to the rotary design, the cylinders slide past both an intake
and an exhaust port. A spark plug deletes the need for a valvetrain. Each cylinder
completes three power strokes per revolution! All this adds up to one very
lightweight, compact, and powerful engine. - VC TURBO
Just released by Infinity, ‘VC’ stands for ‘variable compression’ ratio — yes,
you read that right. Essentially, the stroke of the piston is adjusted to affect
compression from 8.5:1, when you’re hard up it, to 14.1:1 during idle and high
cruising. How? Instead of the rod connecting directly to the crank, it connects
via a bell crank, which centres on the crank. The other end is connected to
another cam-like shaft, which is elliptical and controlled by an actuator. The
engine also uses a mix of both conventional and direct injection.- GASOLINE COMPRESSION ENGINE
Getting diesel-like mileage from a petrol engine is the dream of many
manufacturers, but who knew achieving it would be so damn simple?
Using compression ignition like a diesel, this 2.7-litre three-cylinder
engine uses opposing pistons in each cylinder to compress the air–
fuel mix until it ignites, driving two crankshafts joined by one larger gear
drive. The first production version is set to hit the market in the US,
powering the F-series Ford trucks and offering 201kW and 650Nm. - LIQUID PISTON ENGINE
Here’s one for the rotor-heads out there. It takes the traditional Wankel
rotary engine to the next level. An eccentric shaft is driven by an oval-
shaped rotor that spins inside a housing. The rotor actually carries the
air–fuel mix through the combustion cycle, allowing the engine to have a
constant volume — unlike a conventional engine, which has constant
pressure. Maintaining constant volume in the combustion allows for a
higher compression temperature and better atomization of the mix. In short,
it’s a far more efficient combustion.
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THE COMBUSTION ENGINE – IT AIN’T DEAD YET!
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