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evolutionmovement wrote:Torque curve vs. torque curve is more important than peak number. I also think some manufacturers approximate the amount of work done by their engines as compared to number of ponies. In real life, I've found Subaru engines to have more muscle than cars with engines boasting same or a little more numbers. A 160HP Honda Civic Si hatch (same approximate weight also) only pulled on my low compression 2.2 when I ran out of rpm somewhere around 80mph. I'm not saying these engines are best in class, but they are far from worst.

Well said...

Honda may be able to get comparable numbers out of a smaller motor, but their power curves blow chode...and make driving anything other than a 1500 lb hatchback a total bitch

If it's about auto-x needs, regear the car. Get an RA ratio mainshaft with taller 1st and 2nd gears. That will be 1/3 of the price of getting the engine and EM to hit 7500-8000 rpms.

Even Zyzzx Motorsports 220whp (300chp) USTCC Impreza (which cost them close to $15,000 in motor alone) uses a redline around 7200 rpm and peak power down around 6200-6400 rpm. The bottom ends on the EJ25 just don't take well to sustainted revs above 7500 rpms. And to build them for that is in the ballpark of $4000 or so...

2.2L complete engine $200 off local recycler
Spare complete intake off Ebay $40 had Diamond pack Ha Ha
3 X 2.5L blocks $150 2 where bad, one goodish
4 new stock pistons. $55 each
Rings $137
Bearings $155
2 X 2.2L heads $50
1.8L cams + rollers ,turbo pump, plus a few odd bits $200
Delta grind $175
2.2L Ebay head gasket set $50
2.5L Subaru head gaskets $86
Header $169
Various sealants and gease $25
Clutch/Plate $400
Used flywheel Ebay $100
new flywheel plate for above $55
Input shaft conversion $125
High flow cat Ebay $55
Exhaust was a home brew job.
Pulley Ebay $20
Timing belt Subau $86
Oil cooler Ebay $10
remote filter kit $90

Total=$2573 give or take a few $$$

Oh I forgot the Header for $350

The best test will be doing Rim of the World rally next month!

Yeah, 2.5 liters is really at the maximum limit of what a 4 cylinder should be and those big pistons get mighty heavy thrown around at such high rpms. Don't imagine the HGs and cylinders would like it much, either.

Dude! I'm moving to MA in June. I will have the only rust free Legacy on the East coast! Madza 3's don't ya just love 'em.

Didn't Porshe build the biggest CC 4 cylinder for the 944? with balance shafts etc.

944 S2 and 968 both ran a 2990cc engine, and they did use balance shafts on it to reduce vibration. Those engines don't really like to rev that high either...

They had 4 cylinders as large as big blocks in the 10's, but they probably didn't hit more than 2.5k nor were they expected to take a lot of miles.

You're moving mid-state? What kind of job brings you here?

IIRC there were a lot of monstrous engines back then in the realm of 17L straight 8's and things too right?
968's are the shit.

Maybe aircraft-powered LSR cars, but the largest engine ever installed in a passenger car was the Bugatti Royale's 12.7L I8. They even used it to power trains when nobody bought enough of the cars.

All righty then. So far I've decided to get an EJ25 with stande along ECU, PnP heads and intake manifold, upgraded cams and valvetrain.
I guess with increased displacement and torque I can change dif. ratios... Is it possible to combine 3.7 gears with viscous LSD togeter?
What is the highest compression can be used with regular unleaded gas? Or should I just get 11.1 pistons and leave it like that?
For extra info only: How much does stock piston weigh on the EJ25? EJ22?

I wouldnt go above 9.5:1 on regular gas if you're going for aggressive timing.

Also, I'd go with a shorter ratio, not a longer one. 4.44 out of a Forester. Dont forget you need to change both diffs, front and rear. It's easier to just swap trannies than change your front diff.

You might consider getting headers if you're going for a higher revlimit, you might lose some of your bottom end, but you'll get more top. Also, if you're building it for high-revving, I'd recommend putting in an EJ22T or JDM AVCS oil pump, to supply higher volumes at high RPM.

Lightened pulleys or underdriven pulleys (if you're not putting in a big stereo) would also free up some power.

If you're rebuilding the engine, I'd recommend a precision balance, and a valve job too. If you can find a shop that can put in bigger valves and/or sodium filled valves, that might be an idea too.

Matt Monson wrote:944 S2 and 968 both ran a 2990cc engine, and they did use balance shafts on it to reduce vibration. Those engines don't really like to rev that high either...

Holy crap that's huge.

Toyota has a 2.7L I4 they put in some of their small trucks.

I'd get the taller ratio also. The good thing about power is that you don't need as much to move along and can rev lower at a given speed for increased mileage.

Older Subarus had 3.7 LSDs. Datsun guys love them since they use the same rear ends. There's not much between a 3.9 and 3.7, though. I looked into this and it didn't seem worth the trouble. If you do the calculations out, you'll see what I mean. You could get a slightly taller tire and make the difference.

Forget messing with ring and pinion ratios (which you do need to do twice on our AWD trannies). Do the RA mainshaft with taller 1st and 2nd gears. Run the numbers on a gear chart. You will see that it probably gets you right where you need to be without and sacrifice to highway driving...

How much does an EG33 weigh anyway?

I figure a DOHC EJ25 longblock and accessories (intake manifold, oil pan, injectors, plugs, wires, everything) is probably about 280lbs or so, give or take 20 or 30 pounds.

IronMonkeyL255 wrote:

Matt Monson wrote:944 S2 and 968 both ran a 2990cc engine, and they did use balance shafts on it to reduce vibration. Those engines don't really like to rev that high either...

Holy crap that's huge.

Toyota has a 2.7L I4 they put in some of their small trucks.

3rz in the tacoma, its a great engine. buckets of torque.
I'd guess the eg33 is around 380lbs?

Can anyone recommend a good place to order high compression pistons, valves, timing belt, rods, bearings, and all other good stuff to build the 2.5 NA engine? Places like cobbtuning and xcceleration seem to be a little expensive, plus they no longer list much of the internal engine parts for NA engines.

Wiseco, JE, and Race Engineering will make you custom pistons at whatever ratios, you need. As for the internal parts, I'd go with genuine Subaru parts. Contact Jamie.

Subaru_for_Life

rally370 wrote:Dude! I'm moving to MA in June. I will have the only rust free Legacy on the East coast!

I've got a white SS with no (well, very little) rust. Bring it!