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Old 02-26-2017, 03:28 PM   #1
Redwooods
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Member#: 423625
Join Date: Jun 2015
Chapter/Region: RMIC
Location: Boulder, Colorado
Vehicle:
2005 WRX Wagon
WRB

Default Building a reliable hybrid motor in 2017

I had this posted in the EJ 2.0 discussion, but it's probably better here. I realize there are a ton of threads in the history of this forum on hybrid builds, but many of them are a couple years old and I have a few questions I was hoping you guys could answer for me that I was unable to specifically find through digging.

A little background info: Rod knock in 2005 wrx bottom end (car has 130k) and have brought to a reputable shop in my area who specializes in hybrid builds (205 heads on 257 bottom end). They recommend: Sti shortblock used or new with forged JE Hybrid pistons to compensate, acl race bearings, rods, etc. They also recommended all new hoses, timing belt, rebuilding stock turbo, etc.

I want my hybrid build to be as reliable as possible and if possible add a little more power. I don't rally, drag, launch, etc. I am a pretty conservative driver who likes to punch it from time to time. I just want reliability for this car because I still owe on it and am using most of my savings to rebuild this engine. I would be very happy with 250whp. The car right now has 3" Turbo back exhaust, silicone turbo inlet and an etune. Those are the only performance modifications.

1. Is there a difference between buying used case halves or a new ej257 oem shortblock. My mechanic said finding used case halves and machining them would be cheaper than a new SB. Is there a reliability difference?

2. My mechanic said the new JE hybrid pistons make up for the compression issues and that boreing out the heads is not needed with these. Should I still have the heads matched or have people had really good success with these pistons in terms of reliability?

3. When I replace the clutch while the engine is out, do you recommend getting a new stock clutch or upgrading? I want my original 5mt to last as long as possible.

4. Since I am aiming for 250whp, I most likely need to upgrade my turbo and fuel system. Will a vf39, vf43, VF48, vf52 all directly bolt on? A td05 seems like a good turbo for me but pricier. When buying a used turbo, how many miles is too much as long as the shaft play and wastegate are solid? Should I be worried about putting a 20,000 mile turbo in good shape on a new hybrid engine for longevity? I only really care about low end because I won't be doing highway pulls, just random spirited runs through town from time to time.

5. Is there anything else I should include to protect my engine life? I plan on replacing all the hoses, timing belt, all new gaskets and seals, etc.

My main concern is that most people say hybrid builds don't last as long as factory, consume oil, etc. Ideally this engine would last 100k miles for me. My mechanic has convinced me that hybrids now are just as reliable as a factory bottom end.

I appreciate any input. Thanks!
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Old 03-20-2017, 04:51 PM   #2
svynx
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Member#: 210371
Join Date: May 2009
Chapter/Region: MAIC
Location: York, pa
Vehicle:
2002 hybrid 16gxt
'03 Lifted TS

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Quote:
Originally Posted by Redwooods View Post
1. Is there a difference between buying used case halves or a new ej257 oem shortblock. My mechanic said finding used case halves and machining them would be cheaper than a new SB. Is there a reliability difference?
Not really.

Quote:
Originally Posted by Redwooods View Post
2. My mechanic said the new JE hybrid pistons make up for the compression issues and that boreing out the heads is not needed with these. Should I still have the heads matched or have people had really good success with these pistons in terms of reliability?
No. The hybrid piston takes care of the differences between the 2.5 block and the 2.0 heads. No head machining needed (unless you want to do porting or increased valve size).

Quote:
Originally Posted by Redwooods View Post
3. When I replace the clutch while the engine is out, do you recommend getting a new stock clutch or upgrading? I want my original 5mt to last as long as possible.
I'd recommend talking to your tuner about what they think would be the best match. Personally, I like Southbend.

Quote:
Originally Posted by Redwooods View Post
4. Since I am aiming for 250whp, I most likely need to upgrade my turbo and fuel system. Will a vf39, vf43, VF48, vf52 all directly bolt on? A td05 seems like a good turbo for me but pricier. When buying a used turbo, how many miles is too much as long as the shaft play and wastegate are solid? Should I be worried about putting a 20,000 mile turbo in good shape on a new hybrid engine for longevity? I only really care about low end because I won't be doing highway pulls, just random spirited runs through town from time to time.
You can almost hit that power on a fully stock 2.0 engine. If you are on a tight budget, find a vf39 and STi injectors. Personally, I have a Blough 16g-xt on my hybrid with ID1000 injectors.

Quote:
Originally Posted by Redwooods View Post
5. Is there anything else I should include to protect my engine life? I plan on replacing all the hoses, timing belt, all new gaskets and seals, etc.
Get a good oil pickup tube.
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Old 03-20-2017, 04:59 PM   #3
no694terry
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Join Date: Aug 2009
Location: Pittsburgh PA
Vehicle:
98 Forester S/t
all the mods!

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for 250whp, id avoid forged pistons, especially in a colder climate. That power is easy with a stock ej20 bottom end and a vf turbo. stock sti injectors and a decent tune. You could even search importers or ebay for a jdm 9:1 compression block from a Legacy. The extra compression will help spool the vf sooner and add nicer off boost torques. Tune is more critical with this option

$850

http://www.ebay.com/itm/JDM-EJ20H-TW...xYmKJt&vxp=mtr

can probably make that back selling all the parts off the shortblock
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