Subaru debuts third-generation boxer four-cylinder engine

maxxair · Post by **maxxair** » Tue Oct 05, 2010 5:22 am

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.

[Source: Subaru]

http://www.autoblog.com/2010/09/23/suba ... er-engine/

78sti · Post by **78sti** » Tue Oct 05, 2010 9:20 am

Looks like it will be a much shorter unit than the current ej series, as it looks like it has a timing chain rather than a belt and a single drive belt like the ez series. This should make it about 50mm shorter!

Maby they are thinking of making the long impreza/forester nose a little shorter?

It would make it a lot easier to fit into early brumbies ect with the extra room behind the radiator!

AndrewT · Post by **AndrewT** » Tue Oct 05, 2010 10:52 am

I love that the first reply post talks about sticking one in a Brumby

RSR 555 · Post by **RSR 555** » Tue Oct 05, 2010 2:41 pm

Looks good

is the pic of a turbo version? (quadcam) and what is strange to me is they say.. "The bore and stroke is increased" but the engine sizes are still 2.0 and 2.5

can see how that works.

Yes like Andrew mentioned.. looks like the EG33 timing setup

78sti · Post by **78sti** » Tue Oct 05, 2010 3:00 pm

what is strange to me is they say.. "The bore and stroke is increased" but the engine sizes are still 2.0 and 2.5 can see how that works

I was thinking the same thing?

Maby they are allowing for a future bigger 4cyl release maby 2.7 or 3l

Pav · Post by **Pav** » Tue Oct 05, 2010 3:10 pm

I think it's the stroke that is being increased, and might even make the engine undersquare (stroke greater than bore). Probably to help with low end torque.

http://green.autoblog.com/2010/09/29/fu ... ne-claims/

RSR 555 · Post by **RSR 555** » Tue Oct 05, 2010 3:20 pm

Pav wrote:I think it's the stroke that is being increased, and might even make the engine undersquare (stroke greater than bore). Probably to help with low end torque.

http://green.autoblog.com/2010/09/29/fu ... ne-claims/

Oversquare means the Bore is LARGER than the stroke.. and the quote says both Bore and Stroke are increased.

78sti.. lets hope so

Pav · Post by **Pav** » Tue Oct 05, 2010 3:47 pm

I said under square, not over square. And the article I posted said that only the stroke length is being increased.

Pav · Post by **Pav** » Tue Oct 05, 2010 3:51 pm

On another note, does it say anywhere what the engine is gonna be called? As in ea,ej designations

RSR 555 · Post by **RSR 555** » Tue Oct 05, 2010 4:24 pm

Pav wrote:I said under square, not over square. And the article I posted said that only the stroke length is being increased.

Opps.. really sorry Pav.. and must admit I thought the link you posted was the same as the OP's link.. I'll just take my foot out and umm.. hide

Pav wrote:On another note, does it say anywhere what the engine is gonna be called? As in ea,ej designations

Yeah.. Gen1 and Gen2 were both EJ so maybe the same but who knows??

Pav · Post by **Pav** » Tue Oct 05, 2010 4:48 pm

HaHa all good, its easy to mix the two up, i had to double check myself as well

It seems there is a bit of negative feedback from alot of the comments I read about the engine in other forums etc., but I would be interested in how it changes the drive of the car (better drivability etc.) because there hasn't been all that much info released so far (power, torque etc.)

RSR 555 · Post by **RSR 555** » Tue Oct 05, 2010 5:12 pm

Sweet.. Thanks Pav

It has got me very interested in this new engine and I did find this that answers a few quetions I had

http://www.carsguide.com.au/site/news-a ... xer_engine

nncoolg · Post by **nncoolg** » Tue Oct 05, 2010 5:47 pm

I just read someones ignorrant comment on one of those blogs that said 'Huh,no direct injection-fail subaru'

First of all, 'Fail' - really??? If you are talking in teen xbox talk you really don't know much about engines,

And second, just because it isnt mentioned doesn't mean it isn't there, the press release didn't mention that the engine had a throttle body either, OMG-do you think it has one?

Maybe they drive a commodore with so called 'SIDI' and think they're driving the latest thing, well guess what mate, at least the forester's power windows will make it out of warranty! Poor dudes face would droop faster than a new VN owner in '89 when he found out the buick V6 had been around since the 60's! Oh-oh, even better maybe he has a VL and brags about the engine being so advanced that Nissan put them in the skylines!

Anyway,who really cares until they do a turbo one! Especially since it has a timing chain! (remember the old timing chain rattles from the 80's that got us all excited about belts, well, it looks like the old school is back!)

Gannon · Post by **Gannon** » Tue Oct 05, 2010 6:15 pm

RSR 555 wrote:Yeah.. Gen1 and Gen2 were both EJ so maybe the same but who knows??

Um... Gen1 was EA

I would really like to see a complete list of specs for this engine, maybe have a flick through the FSM for it.

It appears to be using similar principals to the EZ36.

Longer stroke with funny shape conrods to improve torque and efficiency.
Timing chain.
Variable valve timing on both intake and exhaust.
Different head design with super shallow heads, reducing engine width.

I dont like that they have gone back to a belt driven water pump, why not run it off the crank like the EZ?

I really hope they have Direct Injection in the pipeline, and even E85 compatibility. It would make it really competitive against other brands

I doubt this will available with a turbo, as this has been designed with economy in mind, not power.

dfoyl · Post by **dfoyl** » Tue Oct 05, 2010 9:12 pm

>>Longer stroke with funny shape conrods to improve torque and efficiency.

All of these changes wouldn't be necessary if Subaru learnt to keep their cars to a reasonable size. The Liberty / Outback is a huge car now (especially the Outback wagon), the Forester looks about as big as a Territory, and the Tribeca could be painted yellow and called a school bus. They had a nice range of family sized cars and now they're too big and heavy. There's not a car in the current Subaru range I would think of buying anymore...

GTlegs · Post by **GTlegs** » Tue Oct 05, 2010 10:11 pm

The new engine designation is FB. The 'increase in bore and stroke' is actually an increase in stroke to bore ratio from the EJ of 0.815 to FB of 1.07 (ie oversquare to underswuare).

Part of the aim is more power potential as usual, but the real reason is fuel efficiency and emissions (the new Euro 5 standard).

RSR 555 · Post by **RSR 555** » Wed Oct 06, 2010 4:22 am

Suparoo wrote:Um... Gen1 was EA

I would really like to see a complete list of specs for this engine, maybe have a flick through the FSM for it.

It appears to be using similar principals to the EZ36.

Longer stroke with funny shape conrods to improve torque and efficiency.
Timing chain.
Variable valve timing on both intake and exhaust.
Different head design with super shallow heads, reducing engine width.

I dont like that they have gone back to a belt driven water pump, why not run it off the crank like the EZ?

I really hope they have Direct Injection in the pipeline, and even E85 compatibility. It would make it really competitive against other brands

I doubt this will available with a turbo, as this has been designed with economy in mind, not power.

Ok.. Sorry I was thinking that too at first but then I thought it may have been the change in cylinder head design in the EJ series.

Subyroo · Post by **Subyroo** » Wed Oct 06, 2010 9:51 pm

nncoolg wrote:Oh-oh, even better maybe he has a VL and brags about the engine being so advanced that Nissan put them in the skylines.

As an old VL owner for 14yrs I would never dare suggest that.