Subaru debuts third-generation boxer four-cylinder engine

[scoobie]

Boxer lovers, the next chapter in your love affair has just begun. Fuji Heavy Industries, parent company of Subaru, has introduced the latest, third-generation boxer engine that will relieve the second-gen after 21 years of service. This is a brand new lump, not a rework, and FHI has built a factory just to produce it.

The bore and stroke have been increased, and it will be available with four cylinders in 2.0- and 2.5-liter displacements. The intake ports have been redesigned, lighter pistons and connecting rods offer reduced internal friction, and separate cooling circuitry for the block and the head are some of the changes that have resulted in a lower emissions and a ten percent increase in fuel efficiency. No power figures are being quoted yet, so we'll have to see how it measures up when it finds its way into production engine bays.

This new boxer will be Subaru's primary engine, and will first be seen in the Forester. Follow the jump for the press release, and you can have a closer look at it the high-res image below.

Subaru debuts third-generation boxer four-cylinder engine — Autoblog

Press Release:

FHI Develops a New-generation Subaru Boxer Engine
New Horizontally-Opposed engine, providing superior combination of environmental friendliness and enjoyable driving

Tokyo, September 23, 2010 - Fuji Heavy Industries Ltd. (FHI) has developed its new-generation boxer engine* that combines the technology and know-how used in Horizontally-Opposed Boxer engines, the core technology that has supported Subaru's unique driving since it was first employed in the Subaru 1000 in 1966. This overall renewal is the first in 21 years, since the second generation boxer engine was introduced in the first Legacy models in 1989.

This new-generation Horizontally-Opposed 4 cylinder gasoline engine, the third generation Subaru boxer engine, showcases Subaru's latest engineering research and development. It offers a new performance level by further refining Subaru's unique expertise in Boxer engine technology. The engine was entirely renewed, starting from the basic structure, while all the advantages of the horizontally-opposed layout were maintained: lightweight, compact, low center of gravity, and superior vibration balance. New-generation improvements include advances in both environmental friendliness, such as an approximately 10% improvement in fuel efficiency, and driving performance for smooth acceleration in all speed ranges. Furthermore, FHI designed the new engine with consideration of the technology's expandability and potential capability to receive further upgrades meeting future environmental measures.

FHI built a new factory at the Gunma Oizumi Plant exclusively for the production of this new-generation boxer engine. This new plant offers state-of-the-art production facilities that make full use of FHI's engine manufacturing know-how developed to date, as well as a highly efficient production system delivering products meeting the highest quality standards.

Major Features of the New-generation Subaru Boxer engine
The overall structure of this engine has been totally renewed, by reviewing the bore and stroke for the basic structure to
allow a longer stroke than current engines. It is designed to achieve high efficiency in basic performance, allowing the
smooth and sporty rotational properties for which Horizontally-Opposed engines are known, while also making improvements in practical torque and environmental friendliness. This engine is available with 2,500 cc or 2,000 cc displacement, both with 4 cylinders. These models will now be positioned as our main engines.

The New-generation Subaru Boxer engine
・ The bore and stroke, the basic structure of this engine, have been reviewed to achieve a compact combustion chamber as well as a long stroke, which was difficult previously due to chassis mounting conditions in boxer gasoline engines. This allows high combustion efficiency, and generates a sufficient mid-low speed torque with improved fuel efficiency and practicality.
・ Improved fuel efficiency has been achieved through optimization of intake port configuration and the addition of partitions inside ports, the use of TGV (Tumble Generated Valve), and the use of an EGR (Exhaust Gas Recirculation) cooler.
・ AVCS (Active Valve Control System) is used on both intake and exhaust valves. For the intake side in particular, an intermediate lock system allows valve timing to be advanced or delayed for precise control over intake and exhaust valve timing, allowing maximum engine performance in output, fuel efficiency, and exhaust emission.
・ The use of lightweight primary moving parts, such as pistons and connecting rods, and a highly efficient and compact oil pump provides an approximately 30% reduction in friction loss and improves fuel efficiency and revolution response.
・ Cooling has been optimized by using separate engine cooling circuitry for the block and the head, resulting in improvements in fuel efficiency and output characteristics.

FHI is fully committed to develop new products on the theme of integrating enjoyable and reliable driving with environmentally friendly solutions. This same theme applies to this new-generation boxer engine, which will be
positioned as a main engine and the starting point of its future power unit strategy. Starting with the Forester, the new engine will be deployed in other Subaru products in the future.
* Boxer engine: Also known as a Horizontally-Opposed engine. In this design, the pistons are arranged symmetrically left and right along the crankshaft. When the pistons move, they resemble the punches thrown by boxers, thus resulting in this popular name.

[ej25ti]

=0
my day just got so much better! =D

[West]

I hope the FT86 and 216a receive the updated version Although I think they already have the platform established.

[mick5994]

I wouldnt be surprised to see this as a launch platform in the Coupe, especially the STI version!! (Fingers have never been crossed so much) It would make sense with the new emission regulations here in Europe!!

Please, pretty please Subaru......

[ToyoTech]

New to this forum, been reading for a while, but when is subaru gonna incorporate EPS (Electronic Power Steering) its becoming a standard on Toyotas quick, and 1 less pulley runnin off the crank

[ej25ti]

never really thought of it that way, i was kinda annoyed by electronic throttle control to be honest haha

[G4BROKE]

Reviewed this with da boys at the shop and surely it's NA and will not be around for 1 or 2 yrs. Likely it's just for the "consumer" car forrester/outback/legacy? I believe the higher ends i.e. WRX/STI will come with D4S and some of these new tweaks?

ToyoTech.....Where did you get your build done? Eats coolant? not good. Fuel yeah, tune is way off, else other. Where you from? BTW...and welcome to the site!

[ToyoTech]

No tune, upull it speciality parts with a scrapped chassis and body lol

IMO the throttle has gotten better but theres still some kinks to work out

[G4BROKE]

No tune, upull it speciality parts with a scrapped chassis and body lol

IMO the throttle has gotten better but theres still some kinks to work out

LOL...ok...I see why now.

[ToyoTech]

found these on another forum i read here and there, thought i would share if anyone else hasnt stumbled upon these yet, this is an FB25 for a forester









FB20 crank seems to have larger main journals than the EJ20


also reported on there from a student in the process of subaru classes, 6psi for oil pressure at idle and 0w-20 synthetic oil
non-plastic intake manifold for the boosted version please

[West]

Subaru's new 2.0-liter boxer: It's better, but does it matter? — Autoblog

The new FB20 engine is a small step forward from its EJ20 predecessor, featuring better power, emissions and economy (Subaru estimates that mpg is up by around 10 percent). Americans will have to take our word on this improvement, though, as it's been years since we've had a Subaru two-liter sans turbo. The engine pulls off the mild improvement without the help of direct injection – the absence of which is disappointing. GDI is just... what you do when you build a new engine these days. Subaru did think outside of the box with some other aspects though, including designing compact, reshaped combustion chambers, chain-driven cams and intriguingly "bent" connecting rods – the latter allowing installation and maintenance without separating the block.

One of Subaru's proudest points when discussing the new engine is an increase in piston stroke without enlarging the dimensions of the boxer, thanks largely to a modified valvetrain and redesigned block and head. In fact, the piston design changed pretty significantly, from the oversquare EJ (92 x 75mm) to a new undersquare layout of 84 x 90mm. This change accounts for the engine's low-end grunt, and achieving such a stroke increase without further widening the horizontally-opposed engine is admittedly impressive. We're still a little mystified why this feat matters, though, given that all current applications already offer a larger 2.5-liter that fits just fine.

While the new, more efficient unit was designed with an emphasis on improved low- and mid-range power delivery, the Forester we drove was still in need of some decent revs to get around briskly. Its full 148 horsepower hits at a fairly average 6,000 rpm, and torque (146 pound-feet) doesn't peak until 4,200 rpm. Combined with rather long gearing and underwhelming transmissions (a four-speed automatic in 2011, really?), the acceleration isn't exactly crushing. But then again, who cares? You won't be buying the engine in a Forester anyway.

So there we have it, Subaru's new boxer four – an interesting, somewhat old-school engine that's technically better than the outgoing version. But isn't it, in some ways, the answer to the question no one asked? While we're inclined to say a lot more could've been done here, we'll have to see how the new entry-level engine handles itself in the Impreza before locking down an opinion.

[ej25ti]

lol "intriguingly "bent" connecting rods"

[ra23celica]

I have a feeling that Subaru will 'licence' their old motors for Toyota to use in the FT-86, continue to build them at their factory, but bolt-on Toyota's direct injection system. Meanwhile Subaru will be talking up a storm about its new engines in their own cars.

[csusza2000]

I have a feeling that Subaru will 'licence' their old motors for Toyota to use in the FT-86, continue to build them at their factory, but bolt-on Toyota's direct injection system. Meanwhile Subaru will be talking up a storm about its new engines in their own cars.

in that case I'm keeping my money for the Subaru. Anyway we're building our house on a hill, so I will need the symmetrical 4x4 in wintertime.

but please please please FHI put the 3rd generation boxer into the coupe's engine bay.

[Cal]

in that case I'm keeping my money for the Subaru.

You and me both. I am holding out for the 2nd gen suby version.