H6 into Impreza?

[thrashvr6]

I brought this up about 6 months ago in the general forum, and it sounded like the folks at Cobb were working on something to do with the H6..

I love my WRX, but I can't seem to get over the idea of having a flat six under the hood..

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[ciper]

I would love to take ride in one, Ive been in a impreza to WRX swap and it was better than words can describe. The 6 cylinder (although heavy) should be even better, especially with a 5speed!!

[Cacophony]

Untuneable.

Meaning, I hope you will be happy with stock power levels forever

Although I'm sure that Cobb will prove me wrong now

[Red Rocket]

Originally posted by Cacophony
Untuneable.

Meaning, I hope you will be happy with stock power levels forever

Although I'm sure that Cobb will prove me wrong now

Whhhhaaaatttt?

Axis Power Racing has been playing with a built EZ30 (the new legacy H-6) for a while now. The EG33 svx motor has been turboed by some people, the long block is basicly the same thing as an EJ22. EG33's have also been built for high hp sand rails and aircraft engines.

A 400 hp built high compression N/A eg33 might be a pretty sweet setup. High RPM hp, but plenty of torque too. It would probably weigh less than a turboed ej2x engine, and you can always move the engine down and back with some custom work, this would improve the weight distribution.

[quentinberg007]

From what I've heard, the H-6 won't fit in the bay without major modification. It is simply too long. You would kill the value of your WRX too. Why not get an old impreza L that you could cut to hell? (~$3000) Makes much more sense than ruining a 2 year old car.

~~Quentin

edit: I was thinking of the SVX motor. My bad

[MK1ofMnM]

I don't know if it would fit but I have seen the 2.5 and the H6 side by side and to me it looked like only about an inch difference in length.

[svxtrem]

The EG33 is about 4 inches longer. The new EZ30 is only an 1.5" longer. There are two known EG33 into legacy that I am aware of, not sure of how much effort went into it, but they were in Colorado and on the web a couple years ago.

[PeterJ]

The legacy 3.0 H6 is 20mm longer (overall) than the impreza NA/2.5. Thats less than an inch.

[thrashvr6]

Originally posted by quentinberg007
From what I've heard, the H-6 won't fit in the bay without major modification. It is simply too long. You would kill the value of your WRX too. Why not get an old impreza L that you could cut to hell? (~$3000) Makes much more sense than ruining a 2 year old car.

~~Quentin

edit: I was thinking of the SVX motor. My bad

You're probably not wrong about killing the value, though.

I wouldn't be so worried about the tuneability.. I'm pretty happy with the stock power in my WRX. I guess I'd really like to see someone else try it! Or if I could break even by selling my stock motor. (I doubt that would work out.)

[scotty305]

I've heard that the main problem would be mounting the transmission. The EZ30 is designed for AT only, you can't connect it to a 5-speed. I haven't tried it, but this is what I've read. And I've read a lot.

Ask Cobb Tuning, they could probably give you a good straight answer, with experience to back it up. I bet it's possible, but with lots of custom work. And with the extra cylinders, the walls would be very thin, not strong enough for big HP.

My vote: turbo forester engine, and up the boost. Or USDM STi swap if you can afford it. Heck, if we're lucky, standard USDM WRX's might have 2.5L+turbo someday in the future...

-s-

[serious]

The new 3.0 EZ motor would be your best bet. It is much shorter than the older 3.3 EG engine and has more potential due to the fact it is basically a +2 cyclinder version of the wrx engine.
I toyed with the idea of putting a svx 3.3 engine into my legacy. I bought a wreck svx and took lots of measurements. You would have to make a custom raditator and hoses. Probably no big deal. But then there was the idea of having a hard time getting at the spark plugs. I don't know how the 3.3 would set in there and if the frame rails would make the plugs hard to get at.
Other than those things it would be pretty easy and straight forward swap as it would bolt right it and line up.
The only bad thing i could think of with the ez 3.0 is that it is made for an automatic tranny and not a manual. I would think though if you were building a monster a auto would be your only choice ( other than the costly 6 speed) for reliability.
Good luck
Brent

[Homemade WRX]

It would be very cool!!! I have thought of it and figure it would be most like the porshe C4 (carrera AWD). Which is a hot car. I'd be all for it in an older impreza like mine but I would rip apart a newer WRX for it. Very cool idea that I've been thinking of for a year and a half or so.
I would like to start making cars with a flat six twin turbo on an AWD mid-rear engine chassis. This is the car that inspired my idea and many hours on a cad program working the math. Now only for a few million $ needed to start a car company.
Oh well I still love to dream

[serious]

Just looking at my new wrx motor i don't think you would have to cut up much of anything. I really don't think things have change that much between the ej engines or the frame rails in the cars.
I know a while back when i was looking into built ej25's there was talk about building the new 3.0 along side of the wrx motors. So with that in mind i know there are a few out there or are about to be....
B

[XT6Wagon]

#$%#$%#$%#$%#$%#$%#$%

STOP IT WITH THE "ITS FOR A AUTO ONLY" BS!!!!!!!!!!!!!!!!!!!!!!

It bolts right upto a EJ series tranny, and I'd assume it still uses the EJ flywheel bolt pattern since its cheaper that way.

[serious]

Have you tried this before or seen it done? Or are you just thinking openly about it ?!!
B

[tbd]

this from a svx faq on:
http://my.voyager.net/~tmclane/#_Toc482082552

Can I install a manual transmission?
This is probably the #1 FAQ. Easy answer, yes you can- but it will cost you. The 92-98 Subaru 5-speed gearboxes excluding Loyale and, God forbid, Justy- will bolt up to the engine. The '99 and later trannys use an 8-bolt engine mount so they will not work. You will need to fabricate the tranny mount and add a different drive shaft, as the transmissions are a different length. Just any transmission will not do, you really want the '98 WRX tranny at is it fully capable of handling 300HP. The '93-'94 Legacy Turbo tranny is also a candidate, but is not as strong. The '98 Impreza 2.5 RS might also do the job. All of these are $3500 to $4500 new. You also need to fabricate a hydraulic clutch setup and shift linkage. You also need to change the rear gear to suit the transmission (none listed use 3.54). Figure a total turnkey cost of $7k. Still interested?

note that this info is directed toward svx owners. so we don't need driveshaft change. bottom line, yes it (svx eng not new ez30) bolts up except for extra nuts & bolts on newer trannies that followed phase 2 blocks.

see vanagon/svx tuner's kit and info. note theres no bellhousing adapter included, as none is needed. see below.

http://www.smallcar.com/svx/5spdkit.htm

[serious]

Ummm, we're talking about the 3.0 ez motor in the new outback not the eg 3.3 motor found in the svx. It's very easy to hook up a manual to the eg motor as it's basically a plus 2 cyclinder version of the ej22 engine.
I know the ez 3.0 is the same thing: a plus 2 cyclinder version of the 2.0 wrx engine. I don't know why you couldn't, i've just read that you can't for some reason. I think it had something to do with the mounting of the flywheel or something.
Brent

[Jon [in CT]]

Originally posted by serious
Ummm, we're talking about the 3.0 ez motor in the new outback not the eg 3.3 motor found in the svx. It's very easy to hook up a manual to the eg motor as it's basically a plus 2 cyclinder version of the ej22 engine.
I know the ez 3.0 is the same thing: a plus 2 cyclinder version of the 2.0 wrx engine. I don't know why you couldn't, i've just read that you can't for some reason. I think it had something to do with the mounting of the flywheel or something.
Brent

Hmm. The thread starter titled this thread: H6 into Impreza? So I presume that any Subaru H6 is fair game for discussion, including the EG33. And, for future reference, the assertion that "I know the ez 3.0 is the same thing: a plus 2 cyclinder version of the 2.0 wrx engine." is false. Here are some facts about the EZ30, as reported by http://www.sae.org/automag/globalview_09-00/06.htm:

Subaru had developed an opposed six-cylinder engine, the type EG33D naturally aspirated, quad-camshaft, 24-valve 3.3-L unit that powered the SVX sports coupe. That engine involved adding two more cylinders to the E-family four, sharing the short 75.0-mm (2.95-in) stroke. The E-family was the second-generation opposed-cylinder engine introduced in 1991, which in its latest specification powers current Subaru models.

The new EZ30D, dubbed Boxer 6 for its three pairs of pistons exchanging punches in the all alloy block, is a new design and represents Subaru's third-generation flat unit. Compact size, especially in length, was an essential criterion, as it would have to fit neatly in the Outback and maintain a similar weight distribution to its four-cylinder sister model. The EZ30 adds only 20 mm (0.8 in) in length to the EJ25 2.5-L four-cylinder unit. This was achieved by a new set of internal dimensions, which obviously called for a new block/head design and manufacturing tooling. "Getting a new bore pitch-the distance between two adjoining cylinder centers-is really a once-in-your-engineering-life occurrence," said Sekine, "so significant is its influence." The EZ30D has a 98.4-mm (3.87-in) pitch versus the EJ family's 113 mm (4.45 in).

The EZ30D has an 89.2-mm (3.51-in) bore and 80-mm (3.15-in) stroke, which is not as "oversquare" as the EJ25 2.5-L four, which has a large 99.5-mm (3.92-in) bore and 79-mm (3.11-in) stroke. The EZ six has a total displacement of 2999 cm3.

Following Subaru's tradition, the aluminum cylinder block has two halves, each accommodating three cylinders, and is secured at the center by 19 bolts, 14 of which are at the seven bearing journals and five at the top of the horizontal block. Cast iron liners are cast in the high-pressure, die-cast, open-deck block. The block's structural rigidity is further enhanced by a die-cast aluminum upper oil pan. The engine is attached to the four-speed automatic transmission via 11 bolts, versus the four-cylinder's eight. Still the inline drivetrain is quite long, as it houses the final drive, transmission proper, and all-wheel-drive transfer unit. Gussets to enhance drivetrain rigidity tie the engine and transmission together.

On the lower end-more precisely, at the mid-height-the forged carbon-steel crankshaft is supported by seven main bearings of 64 mm (2.52 in) diameter. Four different bearing widths are used: the narrowest being 17.6 mm (0.69 in) and the widest 21.2 mm (0.83 in), which is a thrust bearing type, arresting the shaft's fore-aft movement. The crankshaft length is 406.1 mm (15.99 in). The crank pins are evenly spaced at 60°. The opposing left bank-right bank cylinder Nos. are 2-1, 4-3, and 6-5. Main bearing No. 7 is a thrust type, arresting the crankshaft's fore-and-aft movement. The crankshaft carries 12 balance webs, which are so thin that Subaru calls them "razor webs."

The second important factor in achieving the engine's short overall length is the use of two-stage timing chains, instead of a single timing belt used in the EJ four-cylinder engine (and the EG33D six). Each bank's dual overhead camshafts are driven by its own chain. The two-chain, two-stage arrangement uses the opposed six-cylinder engine's offset cylinder layout, squeezing the crankshaft-driven left-hand (LH) chain neatly in the offset space. The LH chain also drives the coolant pump. The right-hand (RH) bank chain is driven by an idler sprocket, which is driven by the LH chain. Each chain drives three cylinders and is subjected to torque fluctuation so it has to be robust, thus the use of a 9.525-mm (0.38-in) pitch chain-"an unusually wide pitch in this day of 8- or 6-mm (0.31- or 0.24-in) pitch," conceded Sekine. "A single-chain drive would have offset the torque fluctuation, but then one must consider the timing system's reliability and durability, especially in North America where long-distance driving at higher speeds is the norm rather than exception."

Dual overhead camshafts in each bank operate four valves per cylinder via bucket tappets with clearance-adjusting shims inserted on top. The camshaft is a lightweight, built type, with sintered lobes pressed onto the carbon-steel shaft. Sekine observed that there are two schools of engine designers in Japan, one preferring relatively low valve lifts and the other high lifts. Subaru belongs to the latter, employing 9.75-mm (0.384-in) lift for intake and 9.2 mm (0.36 in) for exhaust. Valve diameters are 35 mm (1.38 in) for intake and 30.5 mm (1.20 in) for exhaust.

Fuji's engine designers exploit the incoming charge's tumble motion to promote fast burn in the new six-cylinder engine-a strategy first used in the U.S.-bound Legacy's SOHC 2.5-L four-cylinder engine. This is achieved by a pair of "tumble straight" intake ports for each cylinder. It works particularly well, according to Sekine, in Subaru's opposed cylinder engines, presumably because of the incoming charge's inertia mass, which strengthens tumble motion. The engine operates on the leaner side up to about 3000 rpm to improve economy during low- and mid-load conditions. The injector sprays fuel in two directions and is air-assisted to promote fuel atomization. The EZ30D employs a variable-length induction system, using inertia and resonance charge effects to improve cylinder filling.

The six exhaust ports on each bank collect into a single outlet within the cylinder head, leading to a three-way catalytic converter of 1.0-L (60-in3) volume via a front exhaust pipe. Two rear exhaust pipes from the primary converters merge into an underfloor secondary three-way catalytic converter of 0.5-L (30-in3) volume. Each front exhaust pipe, immediately aft of the manifold, is fitted with an air/fuel ratio sensor. A Lambda O2 sensor is positioned after the secondary underfloor catalytic converter.

The EZ30D engine produces 164 kW (220 hp) at 6000 rpm and 289 Nom (213 lboft) at 4400 rpm on a high 10.7:1 compression ratio using premium-grade, unleaded fuel. The Legacy Outback-6 meets U.S. LEV emissions standards.

Let me repeat the portion of that description which ought to be of interest in this discusion:

The engine is attached to the four-speed automatic transmission via 11 bolts, versus the four-cylinder's eight. Still the inline drivetrain is quite long, as it houses the final drive, transmission proper, and all-wheel-drive transfer unit. Gussets to enhance drivetrain rigidity tie the engine and transmission together.

.

[serious]

Ok, here's where i'm comming from, it's pretty much common knowlegde these days that you can hook up a manual transmission to the 3.3 eg. The svx guys do it all the time, there's even a kit out now for it. So with that in mind i was thinking that the poster was referring to the newer H6 3.0.
I know there are some differences that's why i said "Basically" and not exactly.
But anyway thanks for posting that link as i want to know more about this engine anyway.
Brent