• Best Naturally Aspirated Engines in Human History

The best of those that can do without forced induction

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When BMW rolled the 2002 Turbo towards the tail end of 1973, in the middle of the fuel crisis, everybody viewed it as insanity. Still, as years rolled by, the classic adage that said ’there’s no replacement for displacement’ seemed to hold true for at least some manufacturers. However, ever stringent pollution regulations and the need for increased efficiency pushed carmakers to embrace forced induction more broadly and strangled naturally aspirated engines one by one. Nowadays, big players such as BMW don’t even offer a naturally aspirated engine across their entire lineups and even Ferrari is all but ditching the engines that made the Prancing Horse legendary through their expertly honed soundtrack.

It’s not necessarily that naturally aspirated engines are going to go extinct in a matter of a handful of years but it’s clear that the performance levels achieved by turbocharged or supercharged units simply can’t be matched by a naturally aspirated engine. On top of that, an engine that uses forced induction is more economical due to its smaller capacity and friendlier with the environment which - in the eyes of everyone but some purists - is a win-win situation. While we love turbochargers and superchargers, we thought we’d take a look at some of the history’s best naturally aspirated engines at a time when fewer and fewer manufacturers still offer them - at least in performance cars. We assure you they are proper bangers!

BMW S70/2 V-12 - McLaren F1

Best Naturally Aspirated Engines in Human History High Resolution Drivetrain
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This was a natural choice for us. The engine that powered McLaren’s first modern road car and the fastest of all road cars up until the arrival of Bugatti’s brash but luxurious Veyron, a car that existed simply because Ferdinand Piech wanted it to exist. Similarly, the McLaren F1 was the brainchild of one man, McLaren’s Technical Director at the time, Gordon Murray. The Briton, who’s now working on a successor to the legendary F1, but the engine wasn’t something that he envisioned right off the bat.

Originally, Honda, McLaren's engine supplier in F1 back in the late '80s, was supposed to deliver the engine for the road car but the Japanese had nothing on offer that could match Murray's requirements.

In the end, BMW was chosen and, under the watchful eye of conductor Paul Rosche, the marvelous S70/2 V-12 was born. With a capacity of 6.1-liters, it had nothing to do with BMW’s existing 5.6-liter S70B56 V-12 that powered the 850 CSi as it was the only V-12 made by BMW with four valves per cylinder. This V-12 would also be the only to sit in an engine bay lined with genuine gold to relieve heat. Indeed, its figures were also golden: 618 horsepower at 7,500 and 455 pound-feet of torque at 4,000 rpm, enough to launch the F1 from naught to 60 mph in 3.2 seconds. Insane? Yes. But also reliable as Rosche insisted that "this engine should be designed, developed, like any other BMW series engine. It should not need an opening for 250,000 kilometers."

BMW S70/2 V-12 specifications
Cylinders V 12 in 60° vee
Capacity 6.1 litre
Compression ratio 11.0:1
Bore × Stroke 86 × 87 mm
Bore/stroke ratio 0.99
Horsepower 618 HP @ 7,500 RPM
Specific output 101.9 bhp/litre
Torque 455 LB-FT @ 4,000 RPM
Acceleration 0-60 mph 3.2 s
Acceleration 0-62 mph 3.6 s
Acceleration 0-100 mph 6.4 s
Standing quarter-mile 11.1 s
Maximum speed 240 mph

Read our full review on the 1993 McLaren F1.

Honda F20C Inline-4 - Honda S2000

Best Naturally Aspirated Engines in Human History
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While looking for impressive engines to compile this list, we thought about including the Mercedes-AMG-designed V-12 that’s been the heart of all of the Zondas built by Pagani for almost two decades. While that engine has been developed extensively and, in its most raucous version it cranks out something like 750 horsepower, we thought we should instead include something with a similar horsepower-per-liter figure: Honda’s 2.0-liter F20C that powered the Honda S2000 (in the U.S., only the AP1 version came with the F20C as the facelifted AP2 also brought the bigger F22C with a lengthened stroke).

In Japanese guise, the F20C cranked out 247 horsepower at a mind-bogglingly high 8,300 rpm and 161 pound-feet of twist at 7,500 rpm.

With 123 horsepower per liter (thanks to an increased 11.7:1 compression ratio compared to the European version), the S2000 boasted the highest specific output of any N/A engine at the time of its release and still is impressive today, 20 years on. With titanium connecting rods, slivers of cylinder walls, and three levels of variable valve timing, the F20C was definitely not skimping on materials and this was needed given the outrageous 8,900 rpm redline (that made it sound like one of Honda’s F1 engines) and the even more outrageous reliability of this unit that allowed the S2000 to top J.D. Power’s Vehicle Dependability Study in the ’Premium Sports Car’ class on three different occasions.

HONDA F20C INLINE-4 specifications
Cylinders Inline-four
Capacity 2.0 liter
Valvetrain 16-valve DOHC
Compression ratio 11.7:1
Bore × Stroke 87.0 mm x 84.0 mm
Horsepower (JDM version) 247 HP @ 8,500 RPM
Specific output 123 bhp/litre
Torque 166 pound-feet @ 7,500 RPM
Acceleration 0-60 mph 4.7 s
Acceleration 0-62 mph 5.6 s
Acceleration 0-100 mph 14.2 s
Standing quarter-mile 13.7 s
Maximum speed 150 mph

Read our full review on the 2003 Honda S2000.

Lexus 1LR-GUE 4.8-liter V-10 - Lexus LFA

Best Naturally Aspirated Engines in Human History Drivetrain
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The Lexus LFA is the definition of a halo car. Greenlighted by Akio Toyoda to prove that Lexus is capable of creating a thoroughly exhilarating and dramatic car, and not only dull, soulless executive sedans and SUVs for accountants, the LFA wasn’t perfect. After what can only be called a very prolonged gestation period, the end result fell short off the expectations of automotive pundits who bashed its weight and its less-than-ideal gearbox. But nobody dared to even try and fault its engine.

That engine, the 4.8-liter 1LR-GUE V-10 is a jewel, one that should be in the MoMA next to whatever is considered 'art' nowadays because the LFA's front-mounted 552 horsepower symphonic orchestra is surely a piece of art.

Yamaha’s music division was contracted to develop the car’s exhaust engine with its note described by the engineers behind it as "the roar of an Angel". We tend to agree and we’re not alone, Jeremy Clarkson recently claiming that the LFA remains the best car he’s ever driven "because of the noise it makes principally," adding that the soundtrack of the Japanese supercar is "spine-tingling". Too bad, then, that there are still unsold LFAs out there today...

LEXUS 1LR-GUE 4.8-LITER V-10 specifications
Cylinders V-10 in 72-degree Vee
Capacity 4.8-liter
Valvetrain 40-valve DOHC
Compression ratio 12.0:1
Bore × Stroke 88.0 mm x 79.0 mm
Horsepower 552 HP @ 8,700 RPM
Specific output 110 bhp/litre
Torque 354 pound-feet @ 6,800 RPM
Acceleration 0-60 mph 3.5 s
Acceleration 0-62 mph 3.7 s
Acceleration 0-100 mph 7.8 s
Standing quarter-mile 11.8 s
Maximum speed 202 mph

Read our full review on the 2011 Lexus LF-A.

Porsche Mezger 4.0-liter flat-six - Porsche 911 997.2 GT3 RS 4.0

Best Naturally Aspirated Engines in Human History Drivetrain
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Hans Mezger has worked many a Porsche powerplants over the years but, in recent times, when Porsche fans talk about a ’Mezger’ engine, they usually refer to the dry-sumped M96/72 that has powered the 996 and 997-generation 911 GT3s. The engine, with its deep motorsport roots having been designed for the 911 GT1 race car of the mid-to-late ’90s, reached its peak in the 911 997.2 GT3 RS 4.0 model. Launched in 2011 as the swansong of a generation, it was an instant classic: only 600 units were built altogether and just 141 of those were sold in the U.S. originally.

The engine was 0.2-liters bigger (thanks to a 80.4-millimeter stroke) than the one in the standard GT3 RS at the time and it offered a whopping 500 horsepower at 8,250 rpm (it redlined at 8,400 rpm, stupendous for a road-going Porsche).

There was more than sheer power to this mill as the GT1-derived block had a different oil gallery design that ensured the IMS bearing remains lubricated at all times - the M96 and M97 engines suffered from bearing failure due to insufficient lubrication. Many think the 911 997.2 GT3 RS 4.0 is the best GT3 of them all as it threaded that thin line between rawness and technology (it came with a six-speed manual, of course) before turbocharging swept in with the 991-generation. The only issue is that if you don’t have at least half a million at the ready, you can forget about owning a 4.0.

Cylinders flat 6
Displacement 4.0 l (244 ci)
Compression ratio 12.6:1
Bore × Stroke 102.7 × 80.4 mm
Horsepower 500 HP @ 8,250 rpm
Torque 339 LB-FT @ 5,750 RPM
Acceleration 0-62 mph 3.9 s
Acceleration 0-100 mph 7.9 s
Maximum speed 193 mph

Read our full review on the 2011 Porsche 911 997.2 GT3 RS 4.0.

Ford Flathead V-8 - Ford V8

Best Naturally Aspirated Engines in Human History
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We can’t talk about modern naturally aspirated engines without looking back at a unit that really shook the establishment back in the early days, at a time when performance was not readily available for the masses. This all changed in 1932 when Ford introduced the L-head (flathead) push-rod V-8 on an economy car (engines with cylinders arranged in a Vee setup had previously equipped only upmarket vehicles). The engine, with three main bearings to support the crankshaft instead of five as it was customary back then, featured a camshaft placed above the crankshaft like later OHV designs with the valves between the cylinder banks.

Issues with overheating were commonplace as the exhaust manifolds were placed outboard and the ports had to go in between the cylinders to reach them.

In spite of this and, more importantly, its arrival in the midst of the Great Depression, Ford managed to find a market for the eponymous V8 model and it was a big one: just about everyone wanted to trade in their inline-four or inline-six models for a V-8-engined model. Initially, the 3.6-liter small-block was rated at 65 horsepower at 3,400 rpm but, in just two years, the output had gone up to 85 horsepower. In 1939, the 3.9-liter, 100 horsepower flathead debuted for use in the new Mercury models but, by the end of WW2, it became commonplace under the hood of Fords as well. It was considered the best of the bunch and the starting point for many hot rods. In fact, you could say that Ford’s V-8 basically kicked-off the whole phenomenon as powerful engines became available at a cheap price and people could mod their cars for less money than ever before.

FORD FLATHEAD V-8 specifications
Cylinders V-8
Capacity 3.6-liter
Valvetrain 40-valve DOHC
Compression ratio 5.5:1
Bore × Stroke 77.79 mm x 95.25 mm
Horsepower 65 HP @ 3,400 RPM
Specific output 18.7 bhp/litre
Torque 155 pound-feet (1939 MY)
Maximum speed 76 mph

Ferrari Colombo Tipo 168/62 V-12 - Ferrari 250 GTO

Best Naturally Aspirated Engines in Human History
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Enzo Ferrari used to say that ’aerodynamics are for those that can’t build good engines’ and, for what it’s worth, the Colombo V-12 (in its numerous guises) ’built’ Ferrari. Sure, the Prancing Horses of the ’50s and ’60s also relied on inline engines but it was Gioacchino Colombo’s V-12 that kicked things off in earnest with the first Ferrari, the 125S, being powered by the most diminutive (just 1.5-liters) version of Colombo’s 60-degree V-12. It cranked out just 116 horsepower but it helped the first Ferrari model ever made to win six times on the track in 1947 alone. After the 125’s engine came bigger units that powered, in order, the 166, 195, and 212 models, all with the same 58.8-millimeter stroke but with different bores. Power ranged between 104 and 163 horsepower depending on capacity, compression ratio, and number and type of carburetors (the 125, for instance, employed three 30DCF Webers).

In 1962, the most famous of Colombo's V-12s debuted, namely the 250 that would power just about any Ferrari 250 road and race car made throughout the '50s and '60s - including the coveted 250 GTO.

It featured a bore of 73 millimeters with the stroke unchanged at 58.8 millimeters for a capacity of 3.0-liters. Known as the Tipo 168/62 V-12, the 250 GTO’s engine had already proved itself in competition under the hood of the 250 Testa Rossa, in itself a car that underwent a plethora of changes between 1958 and 1961 when it finally became apparent that sports cars needed to be mid-engined to be successful. The engine was dry-sumped, fed via six 38DCN Weber carburetors and, with a compression ratio of 9.7:1, it cranked out 296 horsepower 7,500 rpm. It may not seem that insanely high for a naturally aspirated Ferrari engine but you’d be hard-pressed to find a better engine note from the bulk of the ’60s sports cars - and we’re including here everything from Jaguar’s inline-six to the burbling awesomeness that was Ford’s small-block 4.7-liter V-8 that powered the Cobras. Oh, and it also helped the 250 GTO and many other 250s to win on countless occasions. Furthermore, Colombo’s designs, while improved by his replacement at Ferrari, Aurelio Lampredi, remained in use until the late ’80s.

FERRARI COLOMBO TIPO 168/62 V-12 specifications
Cylinders V-8 in 60-degree Vee
Capacity 3.0-liter
Valvetrain 24-valve SOHC
Fuel feed Six 38DCN Weber carburetors
Compression ratio 9.7:1
Bore × Stroke 58.8 mm x 73.0 mm
Horsepower 296 HP @ 7,500 RPM
Specific output 98.6 bhp/litre
Torque 217 pound-feet at 5,500 rpm
Acceleration 0-60 mph 4.5 s
Acceleration 0-62 mph 5.8 s
Acceleration 0-100 mph 11.6 s
Standing quarter-mile 13.5 s
Maximum speed 174 mph

Read our full review on the 1962-1964 Ferrari 250 GTO.

Chevrolet LS1 V-8 - Chevrolet Corvette C5

Best Naturally Aspirated Engines in Human History
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Before you start giggling at the mere idea that the LS1 V-8 made it on this list, hear us out. Yes, GM’s line of LS motors, but especially the early, more affordable and easier to get ones, have been the subject of internet memes for years by now but there’s good reason (and bad) for that: they’re indeed everywhere and just about any folk with a desire to make his or her car more powerful by merely swapping the engine originally intended for that car can do it for the LS engine is quite small in size (it can fit in the engine bay of an NA Miata but you probably knew that already) and adaptable thanks in part to a huge variety of aftermarket parts available for it. We can’t say we’re fans of LS swapping any car out there but you can’t deny the performance gains and that an LS swap done properly can push a rather anonymous car further than it ever would’ve hoped to go without breaking the bank.

We settled upon the first of the breed, the LS1 5.7-liter small-block V-8, the first engine part of GM's third-generation small-block V-8 family of powerplants.

It debuted all the way back in 1997 on the Corvette C5 when it was rated at 345 horsepower at 5,600 rpm and 350 pound-feet of torque at 4,400 rpm. Power went up to 350 horsepower in 2001 and, by then, the LS1 was already powering F-bodies as well as Holden models. The LS1 was the first with a Y-block design meaning that it came with six-bolt main caps on the crankshaft for added rigidity. The block itself was made out of aluminum (the gen-3 small-blocks for trucks and SUVs feature an iron-cast block) and it was the smaller bore/longer stroke setup that made it compact. It truly is hard to beat an LS1 when you want a boost in performance and you’re on a tight budget.

CHEVROLET LS1 V-8 engine
Cylinders V-8
Capacity 5.7-liter
Valvetrain 16-valve OHV single-cam pushrod
Compression ratio 10.1:1
Bore × Stroke 99.06 mm x 91.948 mm
Horsepower 345 HP @ 5,600 rpm
Specific output 60.52 bhp/litre
Torque 350 pound-feet @ 4,400 rpm
Acceleration 0-60 mph 5.3 s
Acceleration 0-62 mph 5.6 s
Acceleration 0-100 mph 12.5 s
Standing quarter-mile 14.1 s
Maximum speed 170 mph

BMW S14B25 Inline-4 - BMW M3 E30 Sport Evo

Best Naturally Aspirated Engines in Human History
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The story of the 3 Series BMW began with the E30 generation all the way back in 1982. At the time, BMW was entering Group A competition (sedan-type racing in the European Touring Car Championship and other national series that had adopted the same rule set) with the 528i four-door model that, while somewhat competitive, was deemed unfit for the job. Thus, in 1983, the 5 Series racer was duly replaced by the gorgeous 635 CSi powered by the big 3.5-liter M30B34 straight-six. The 6 Series Group A car proved to be the car to beat straight out of the box and won the ETCC in its first season and then again in its last (in the factory’s hands). For 1987, BMW decided to move in the ETCC’s secondary division by entering the more compact and more nimble M3.

The first M3 was effectively built so that BMW could race in Group A and, while the road car was praised for its balanced chassis and poised steering, the S14 four-pot left something to be desired in the power department.

Cue the Sport Evolution version. By 1990, the arms war in the ETCC was getting bigger and BMW realized that its M3 (by then racing in Evo 2 spec) was barely able to keep up with the cars in its own class, let alone challenge for overall victories. This was especially hurtful for Munich in the Deutsche Tourenwagen Meisterschaft (DTM), Germany’s own touring-car series. To amend the situation, BMW homologated the ’Evo 3’ M3 and, to do so, built 600 road-going M3s known as the ’Sport Evolution’ examples. They were powered by a 2.5-liter version of the S14 model that offered 235 horsepower (the Evo 2 M3 put out 217 horsepower). What made this engine particularly special, though, was that it revved all the way to 7,500 rpm and max power was available from 7,000 rpm onwards. Basically, you had nothing up until about 5,500 rpm when the party kicked-off loudly and then it just kept going and going, urging you to dig the loud pedal deeper into the floor. Sure, 235 horsepower is not much by today’s standards but in that package, the experience rivals and maybe even surpasses what you get from modern +600 horsepower supercars.

BMW S14B25 INLINE-4 specifications
Cylinders Inline-four
Capacity 2.5-liter
Valvetrain 16-valve DOHC
Compression ratio 10.2:1
Bore × Stroke 95 x 87 mm
Horsepower 235 HP @ 7,000 rpm
Specific output 94 bhp/litre
Torque 177 lb.ft @ 4750 rpm
Acceleration 0-60 mph 6.2 s
Acceleration 0-62 mph 6.5 s
Acceleration 0-100 mph 17.2 s
Standing quarter-mile 14.8 s
Maximum speed 154 mph

Honorable mentions

Mercedes-AMG 6.2-liter M159 V-8 - Mercedes-Benz AMG SLS Black Series

2014 Mercedes SLS AMG Black Series High Resolution Drivetrain
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Not long ago, almost every car tuned by AMG was powered by the M156 6.2-liter V-8: the S 63, E 63, SL 63, CLS 63, and CL 63 models all came with this behemoth that churned out 518 horsepower and 465 pound-feet of twist. This was proof of its versatility and clever design being the first engine developed 100% by the AMG division with no links to pre-existing Mercedes-Benz units. The M156 was first introduced 12 years ago in the CLK63 AMG (it put out 475 horsepower originally) but it was some six years later that this powerplant reached the apex of its development: modified for use in the Mercedes-Benz SLS AMG and branded as the M159, the engine featured an all-new intake system, reworked valvetrain and camshafts, the use of flow-optimized tubular steel headers, and de-throttling of the exhaust system. Lubrication was of the dry-sump variety and, in the AMG Black Series model made until 2014, it cranked out a ludicrous 622 horsepower at 7,400 rpm and 468 pound-feet of torque at 5,000 rpm. That engine basically dominated the character of the SLS AMG Black Series and turned it into one of the most notorious supercar brutes, a true muscle car with gullwing doors and a fancy aerodynamic package. For that and for its across-the-board usage for over half a decade it deserves to be here.

Read our full review on the 2014 Mercedes-Benz AMG SLS Black Series.

Ferrari F136 4.5-liter V-8 - Ferrari 458 Speciale

2014 Ferrari 458 Speciale Drivetrain
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We can’t put our name to an article about the best naturally aspirated engines of all time without mentioning the last naturally aspirated V-8 that made its way in the middle of a Ferrari: the raucous 4.5-liter F136 V-8 as used in the 458 Speciale. To put it into context, a standard 458 Italia’s V-8 was good for 562 horsepower at 9,000 rpm. It delivered expertly in terms of aural nirvana and power was also plentiful but then Ferrari found another 35 horsepower to give the Speciale while torque remained at 398 pound-feet. The red line was 9,000 rpm still and this meant that any ride aboard a 458 Speciale through a tunnel was almost a religious experience. We all cried when Ferrari announced that the 488 GTB would retire what was the engine with the highest average piston speed in production at the time and it wasn’t only car people that reached for their handkerchiefs when the Speciale bowed out as the engine won numerous trophies for its top-notch engineering. Granted, Ferrari kept gathering accolades with the turbo’ed engines that followed...

Read our full review on the 2014 Ferrari 458 Speciale.

Porsche 5.7-liter 980/01 V-10 - Porsche Carrera GT

2004 - 2007 Porsche Carrera GT High Resolution Drivetrain
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When we talk raw 21st-century supercars the same names seem to pop up time and again: some yell ’Noble M600’ while others point to the early Zondas and Koenigseggs that had stupendous amounts of power and little grip. Finally, someone props up and utters ’Carrera GT’. Even if it didn’t lack most of the electronic aids you find on modern supercars, the Carrera GT would’ve been special, massively so. After all, it’s not every day that you stumble upon a car with an engine derived from that of an unborn Le Mans prototype that, in turn, first breathed as an Formula 1 unit. But that’s exactly what the Carrera GT has got under that bulging rear lid that features a pair of mesh grilles so you can see the silver covers of the 5.7-liter V-10 that put out 603 horsepower and 435 pound-feet of torque in 2003. The main thing you must remember if you ever get the chance to slide in those bucket seats, grab that wooden knob (a tribute to the Porsche 917), and turn the ignition is that you must treat the Carrera GT as if you were in a cage with a lion that could be thinking of having you for lunch. The car is unruly and that’s despite the presence of active aerodynamics (the rear wing that jumps up when you exceed 70 mph) or the carbon-ceramic brakes. However, if you do push fear aside and find a long and straight enough piece of road to allow the car to stretch its legs, the sound from that engine is second to none or even better.

Read our full review on the 2004-2007 Porsche Carrera GT.

Michael Fira
Michael Fira
Associate Editor and Motorsport Expert - fira@topspeed.com
Mihai Fira started out writing about long-distance racing like the famous 24 Hours of Le Mans. As the years went by, his area of interest grew wider and wider and he ever branched beyond the usual confines of an automotive writer. However, his heart is still close to anything car-related and he's most at home retelling the story of some long-since-forgotten moment from the history of auto racing. He'll also take time to explain why the cars of the '60s and '70s are more fascinating than anything on the road today.  Read full bio
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