Best EJ block to build??

[Numbchux]

since i havent messed with a 2.0 whats the gain/loss over a 2.5 sb?

 

not a lot. they rev more freely. but even then, the best built boxer isn't reliably going to spin above 7, maybe 7.5k. go for the displacement and torque curve.

 

 

The jdm sti heads are way better than the USDM ones, though.

[renob123]

My typing/"grammar" skills are not gone. The reason I don't use apostrophes and capitol letters "proper written grammar" is because i never cared to add them when you or anyone else can read what I have written just fine AND it slows me down. now if you were my teacher im sure I would make things right.

 

 

 

i like all subaru engine's but the 6's dont have that rumble. that distinct subaru sound is one reason i like subaru. i should be been more specific

 

the "experts" are all leaning towards the 2.5 sort block i was looking at a 2.0 setup .

 

since i havent messed with a 2.0 whats the gain/loss over a 2.5 sb?

 

I certainly took it as you being an rump roast to me when I was just trying to be friendly. If that's not the case, then we can proceed amicably.

 

I believe one of the main benefits of the Japanese 2.0 is that it can rev higher. Of course, you can build a 2.5 to rev higher as well, but I don't see too many people going that route. I seem to see a lot of EJ257s spinning bearings, but I'm not sure if it's because nobody checks their oil or if that motor is not as great as I always thought it was. Most of my research is in the turbo world, so I may be off-base here.

 

Jacob

[renob123]

not a lot. they rev more freely. but even then, the best built boxer isn't reliably going to spin above 7, maybe 7.5k. go for the displacement and torque curve.

 

 

The jdm sti heads are way better than the USDM ones, though.

 

Darn. You beat me to it. Although I thought the stock JDM STI went to at least 8k. Maybe not reliably, but that's where the tach's redline was.

 

Jacob

[thatswhatshesaid]

Hmm, I doubt I'm the reason they think that. Words change meaning over time. The word "hypocrite" used to mean "actor", for example. The word "plates" means "feet" in parts of London. Understanding how to use apostrophes and capital letters does not change with time, though, and I'd normally expect anyone over the age of 10 to have mastered those concepts.

 

 

Jacob

 

I'd like to take a moment to point out how FTW this response is...

If there's one thing I love, it's proper spelling and grammar!

 

/end hijack

 

...proceed.

Edited October 5, 2010 by thatswhatshesaid

[renob123]

I'd like to take a moment to point out how FTW this response is...

If there's one thing I love, it's proper spelling and grammar!

 

/end hijack

 

...proceed.

 

Thank you for the compliment and thank you for ending your hijack. The OP and I (I think. I don't want to put words in his mouth) would vastly prefer that this thread be kept on the topic of retrofitting Subarus.

 

Jacob

[True2Blue]

thank you everyone for you input im going to try a pII 2.5 sb with the sp 1.8/2.2 heads

 

ill post pics of all progress

 

thanks again

[idosubaru]

ill post pics of all progress

 

thanks again

please do. i have all of those parts sitting in my garage as we speak and am tempted to try it.

 

if you find any of the aforementioned discussions about this on other forums, like nasioc, i wouldn't mind seeing those threads if you want to link them here. i only say that since maybe you've already looked.

 

so 180 hp - that's 15 above stock EJ25? 10% increase.

[True2Blue]

please do. i have all of those parts sitting in my garage as we speak and am tempted to try it.

 

if you find any of the aforementioned discussions about this on other forums, like nasioc, i wouldn't mind seeing those threads if you want to link them here. i only say that since maybe you've already looked.

 

so 180 hp - that's 15 above stock EJ25? 10% increase.

 

ill link everything tonight ive found 3 sites and have done alot of reading im trying to get mt knowledge up to par im learning trigonometry right now. now i have to learn the subaru engines bore stroke cam valve yada yada yada all the numbers then learn how to change the numbers to make more hp..

 

i can read elsewhere and learn it just fine (i have teachers moms bf is a 30 year master tech) and buddies dad is a master tech at GM here in town and teaches at the college) but i like you guys

 

and i dont know wht your doing sittin on the comp id be out there making a BEAST

[GeneralDisorder]

so 180 hp - that's 15 above stock EJ25? 10% increase.

 

Maybe more. The deal is..... the DOHC heads *could* be built up to flow better and easily outstrip the frankenmotor in performance. But the cost to do so is rediculous. The cost for a frankenmotor build with 22 heads for renob123's Brat was $700. It would have DOUBLED if he had used 2.5 heads. The cams are more expensive per-each and you need twice as many. It would be like $500 in cams. Then the port/polish work would be several hundred more.

 

The goal of the frankenmotor is excelent performance for cheap. It accomplishes that. If you spend a little time gathering parts it's actually very little more expensive than a regular 2.2 and bolts right in place of one. It's a very sneaky and cheap power upgrade.

 

Basically you take any EJ22/EJ18 car (swapped or otherwise), pull the engine for a head-gasket job, and sneak an EJ25 block in under the old heads.

 

GD

[Numbchux]

It's a very sneaky and cheap power upgrade.

 

....to build.

 

 

 

 

BUT, you have to keep in mind, it will require premium (91+ octane) fuel due to the high compression.

[True2Blue]

100% okay with that i run it anyways

 

im gettin close to gettin my ol wagon back

Edited October 6, 2010 by True2Blue

[LeoneTurbo]

And for god's sake if you really want to run a 2.5L block, get the deck resurfaced unless you want to replace head gaskets every 10k miles or so.

[idosubaru]

probably on par with most EJ22/Ej25's as far as fuel mileage right (if you can keep your foot out of that new found power )?

 

gotcha - it's a huge upgrade from an EJ18/EJ22 but more modest if you're just doing it on an EJ25 vehicle.

[renob123]

probably on par with most EJ22/Ej25's as far as fuel mileage right (if you can keep your foot out of that new found power )?

 

gotcha - it's a huge upgrade from an EJ18/EJ22 but more modest if you're just doing it on an EJ25 vehicle.

 

I haven't run mine that much, but fuel economy doesn't seem to have changed.

 

The gains aren't just "more modest" when you already have an EJ25. They're questionable or even pointless, from what I understand. The 180hp number is an estimate, and if my Frankenmotor is anywhere near that, then it's being helped out by the cams. If you started with an EJ25 vehicle, you'd probably be better off just going with cams than sourcing EJ22 manifold/wiring/heads and dealing with the worse flow of that setup. If you'll die without the increased compression, there are other ways of doing that without downgrading the heads. If one can only afford 2 cams and not 4, then maybe one shouldn't be doing any kind of build.

 

This isn't directed totally at you, Gary. I just want to share some of what I understand, and I'd advise everyone to do their own research because I'm not an engine builder by a long shot. I just wasn't impressed with just the EJ22, and I found an EJ25 shortblock on NABISCO, so that's why I did it.

 

Jacob

[True2Blue]

what twin cam head has "high flow" and high compression?

Edited October 6, 2010 by True2Blue

[renob123]

what twin cam head had "high flow" and high compression?

 

I don't know of any NA Impreza that needs premium fuel, so I'd venture to say that none of them are really that high of compression.

 

Jacob

[thatswhatshesaid]

I would love to have a high-comp N/A motor in my Outback for offroad purposes... too bad I wouldn't get much more power if I made a frankenmotor...

[idosubaru]

This isn't directed totally at you, Gary.

right on. i have all the parts, non issue. comparisons are helpful and though one possible candidate was originally EJ25 it isn't now. good chance of picking up another EJ25 vehicle in the next year too and chances are it'll have a blown motor since those are easy to find. Edited October 7, 2010 by grossgary

[rxleone]

not a lot. they rev more freely. but even then, the best built boxer isn't reliably going to spin above 7, maybe 7.5k. go for the displacement and torque curve.

 

 

The jdm sti heads are way better than the USDM ones, though.

 

That's not true - I used to own an 89' EJ20D DOHC N/A that had a redline of 7500RPM, all the Legacy RS's had a redline of that as well. Subaru engines will happily rev as high as they're balanced for.

[SubiDemon]

I called Delta and had a few questions cleared up about the 2.2 cam regrind that people have talked about in this thread.

• The regrinds work with HLA's. Since there is no adjustment with HLA's you have to use shims to make up the difference. I believe they provide the shims.
  
• If you have a head with HLA's and would like to convert it to a solid lifter head, the 2.2 solid lifter rockers bolts right on. I asked if the 1.8 rockers would work (I believe those were solid too) and he said it may.
  

[LeoneTurbo]

That's not true - I used to own an 89' EJ20D DOHC N/A that had a redline of 7500RPM, all the Legacy RS's had a redline of that as well. Subaru engines will happily rev as high as they're balanced for.

So true. I currently run a 2.2 open deck block with custom made high compression (11:1) forged pistons and a set of those early DOHC heads. The engine runs very, very strong above 5k rpm right to the ECU limiter at 7.2k rpm. There isn't a lot of torque in the midrange though. I'm running ARP rod bolts for better bearing life/stability and a small 7mm oil pump to prevent oil foaming at higher rpm's.

 

I've built the engine early this year and so far it's just cracked 50k kilometers. It is starting to use quite a bit of oil though, about a litre every 1.5k kilometer. But then again, it's been running most of it's life at around 5k rpm in fifth gear on the German Autobahn...

[Numbchux]

That's not true - I used to own an 89' EJ20D DOHC N/A that had a redline of 7500RPM, all the Legacy RS's had a redline of that as well. Subaru engines will happily rev as high as they're balanced for.

 

I absolutely love it when people talk about balancing the rotating assembly so they can rev high. Really sorts out the engine builders from the weekend mechanics.

 

 

balancing has little to do with revving high (I say little, because obviously if it's way out of balance, it won't work...). Allowing an engine to rev, means running very tight tolerances at the main bearings to prevent much crank movement. This isn't as difficult in a small-displacement inline motor because they don't make a whole lot of torque with each combustion, and all the force is directed in the same direction.

 

the smaller displacement of a 2.0 helps in the torque department, but it's still a boxer, which inherently means a lot of crank movement due to the firing order and direction. When you're running extremely tight bearing tolerances, crank movement means contact between the crank and bearings, which means wear. And everytime those 2 pieces contact each other, those bearings are going to shift a bit.....which means you're another fraction of a mm closer to a spun bearing.

 

I know the jdm clusters print the redline at 7.5k. As I mentioned, the 2.0 can get away with it, because it doesn't make much torque, but I still think if you're making more than ~150ft/lbs at the crank, using bearing tolerances that allow 7k+ is asking for trouble.

[LeoneTurbo]

In general terms, you have a good point. However, the main bearings of the EJ engines are big (60 mm) and the crank is very short, so there really isn't a lot of movement. FHI designed the EJ series engine to rev - hard. It just failed to design in in such a way that the rod bearings would last - blame the conrod design. Using STI/Eagle/Carrillo etc on a high revving EJ series and you'll be fine - reliably.

[True2Blue]

anyone ever use over sized valves or thought about using over sized valves on the 1.8 sp heads?

[renob123]

anyone ever use over sized valves or thought about using over sized valves on the 1.8 sp heads?

 

From what I've seen, people who are doing that involved of a build will usually start with a more advantageous platform than the EJ18 heads. Why do all of that work just to get the same flow as some EJ25 SOHC heads that you might find in the junkyard (assuming proper fitment, of course)? I also hear that while visually almost identical, the EJ22 heads will flow better.

 

You may want to ask Ken at Delta cams what he thinks. I'm pretty sure he has torn into a majority of the options, while I basically regurgitate stuff from NABISCO and post up dancing bananas about Frankenmotors.

 

Jacob

 

P.S. Frankenmotor FTW:banana::banana: