3.3 H6 with 230hp vs 3.0 H6 with 250hp?
 

OK, our cars have the 3.3 DOHC H6 with 230hp, but several newer Subies have this 3.0 H6 with 250hp...does anyone know what the exact differences are in the engines? Are the 3.0 H6 heads that much better, and would they fit on the 3.3 H6?

I'm looking to eventually build up a great Subie H6 for another project, and would like some input on possible hybrids, etc.
I will need to build whatever it is up a bit and likely lower compression a bit for up to a 15psi SC unit, but I'm looking for the most bang out of the engine platform itself before I add boost.

Thanks!

The only 3.0 H-6 that I know of is offered in the Outback... and it is 212hp... Where is this 250hp H-6???

if that's the engint that you are talking about then the Cam set up is diffrent... The engine is 300cc's smaller :D:D... And it is an interferance engine.... Ours is so much better :D:D

The new 250 HP USDM '05 Legacy is using a variant of the 4-cylinder STi motor. One version of the new Legacy in Japan uses an H6 motor.

A 4-cylinder 2.5L STi motor in an SVX sounds very interesting to me. Probably would have to use a custom ecu. Not really any aftermarket ecu's available for the STi motor yet though because of the throttle by-wire design the motor uses. Seems that the aftermarket ecu guys have some worries about making it work correctly.

Just checked Subaru's site...I could have sworn the material on the new H6 said 250hp...

OK, new question...What would the best buildup for the 3.3 H6 be, going for reliability, power, and ability to handle boost?
I'm looking to add about 15psi from an Eaton or Lysholm SC, the engine will be mated to a manual and an AWD system with a fixed, rear-biased center diff.

Thanks!

Now there's a question and a half. You'll never get 15 psi with the EG33 on stock internals, at least not for long. You'll need to do forged pistons at the minimum. Some work to reinforce the deck might also be necessary.

What do you mean by a "fixed" center diff?

you are correct. the h6-3.0 available in the 2005 outback will develop 250hp.

best buildup for the eg33

http://www.subaru-svx.net/photos/fil...dTW/14928.jpeg

In Sweden, a Legacy 3.0RS spec B, is released, gonna have 245HP AND a H-6 AND a 6-speed gearbox !!


/Sonny :cool:

I've been asking SOA to get me that forever. They bring it in, I'll get one. ****, I'll even get in line.


As for hybrid, I am thinking of switching my SVX to run on things other than gasoline. In IL, the state will fund 80% of your cost for conversion.

Perhaps next year, I'll have to do a ton of mods on this car.

The mag stated a 6-speed gearbox, I thought it was a MANUAL , it is NOT, it is a 5-speed AUTO with Lockup , maybe that counts a a 6-speed ... I dunno... :rolleyes:

Here it is : http://www.subaru.se/legacy_tek.shtml



/Sonny :cool:

3.3 vs 3.0
 

The 3.0 is shorter, (along the crankshaft) lighter, and has, I believe, no interchangable parts. We have to work with what with what we have. 7 main bearings, forged rods and crank, low center of gravity. All good stuff.

5 speed auto, with a 3:1` diff ratio 0.8 top gear = 2.49:1 overall top gear. Wow they like to fit bloody high gearing.

Though I see this engine uses the same type Inerta Resonate Inlet system that the SVX has. When your got a good system, use it. .:D

Harvey.;)

the same thing my 928 had, in 1987. ;)

subaru made a 4 cyl engine with the same piston sizes as the eg33 but lower compression. The easiest thing would be a piston swap from that engine. I can't remember the model number anymore though. This route would be a heck of a lot cheaper than custom forged pistons.