5 Knockout Boxers That Will Never Disappoint You

1. Subaru EJ20

Think ‘boxer engine’, and the chances are high it’ll be a Subaru flat-four that comes to mind first. The EJ20 - known for the distinctive ‘burble’ in early versions - is one of the most iconic flat-configured engines out there. The turbocharged versions are primarily recognised for powering the hotter Imprezas, but they also made appearances in the Legacy, including a twin-turbocharged car with a meaty 280bhp.

2. 991 Porsche 911 GT3 4.0-litre flat-six

Porsche’s latest water-cooled flat-six is a mighty thing, as we found out recently with the 3.8-litre version found in the 911 GTS (video below). The pick of the bunch is the 4.0-litre unit installed in the GT3 and GT3 RS. In the latter car, it’s good for 496bhp and 340lb ft of torque, enough for a blistering 0-62mph time of 3.3 seconds and a 193mph top speed.

3. Toyota 2U-B flat-twin

This dinky 800cc engine isn’t hugely powerful, but it’s a charismatic unit which more than deserves a mention. Why? Because it powered Toyota’s first sports car, the Sports 800.

While the 4.0-litre engine in the 991 GT3 and GT3 RS is the pinnacle of the water-cooled, naturally-aspirated Porsche flat-six, it’s the air-cooled engine that’s truly regarded of as the proper unit from Porsche. One of the most celebrated air-cooled boxers ever built by Porsche is the 2.7-litre engine that powered the 1973-1974 Carrera RS. When it left the factory it was good for 210bhp, a potent figure in the lithe RS.

5. Subaru H6

The flat-six is an engine configuration used almost exclusively by Porsche, but there are exceptions, like Subaru’s ‘H6’. This boxer-six may not share the same illustrious status as the other engines here, but we have to doff our caps to Subaru for sticking to the unconventional boxer engine, regardless of size. Plus, there’s something awfully tempting about a cheap, used fourth-gen Legacy R Spec B, with its 243bhp 3.0-litre H6. Prices start at just £2000, after all.

Interestingly, despite rocking an extra pair of cylinders, it’s only 20mm longer than the four-pot EJ series engine.

Bonus engine: Ferrari Colombo 'flat-12'

We can’t officially include this one in the list itself, as it’s not considered a true boxer engine. It’s actually a flattened version of Ferrari’s Colombo V12, and unlike a boxer where each piston has its own crank pin, the Ferrari engine has a pair of pistons sharing each pin. Take a look at the GIF below from Air-Cooled Nut if you want an illustration of how this works (the top one is the proper boxer, in case you’re wondering).

The same applies to the equally awesome, and equally non-boxer flat-12 found in the legendary Porsche 917 race car.