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Old 01-19-2021, 07:03 AM   #1
Mindriddle
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Default Replacement engine for my 08 WRX Hatch

I wanted to see what you guys opinion on what direction I should go.

I have an 08 WRX Hatch with a VF52 turbo (from the 09 up), tuned by Eric from Torqued Performance running his Stage 3.52. Recently, I purchased the cobb flex fuel kit with the aem pump and 1050cc injectors. Well, we tuned for 93 but something happened in the engine when tuning for E85. Long story short, I need a new engine as mine has nearly 190,000 miles anyway.

My question is- what is the best (and cheapest) option to get this car back on the road? Ive looked at used engines from ebay and other places but most are selling JDM replacements which is the 2.0L vs the 2.5L in the car. Would those still be a direct swap? I can get a short block from rallysport and rebuild the head as also an option but itll be a bit more in cost.

What do you guys recommend?
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Old 01-19-2021, 07:48 AM   #2
Zak6182
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What are you going to do with the car? Whats your expected hp, mods?
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Old 01-19-2021, 09:09 AM   #3
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What are you going to do with the car? Whats your expected hp, mods?
Well..Its not my daily but I do enjoy driving the car more often than usual when I get bored driving my DD (Audi A4). I plan on starting to do track with this car, hoping to do it this summer. It has all your basic bolt ons; catless dp, exhaust, ebc, intercooler, radiator, intake, etc. It is basically my backup/fun car that I want to keep somewhat reliable and able to track it if decided to do so. Eventually I would want to upgrade from the vf52 turbo.
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Old 01-19-2021, 10:32 AM   #4
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What is your power goal? Are you planning to upgrade the turbo? How much PSI are you planning on pushing? If you plan to stay around stock power, or below 350hp then just get a RA block and call it day, but if you plan on making the eng work hard, then go built block stage 1 or 2. If you plan on using E85 at 350whp, the RA block would be fine for your needs. But if you are then kind of person who will want more power a year later, then build the block for the future.
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Old 01-19-2021, 11:58 AM   #5
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What is your power goal? Are you planning to upgrade the turbo? How much PSI are you planning on pushing? If you plan to stay around stock power, or below 350hp then just get a RA block and call it day, but if you plan on making the eng work hard, then go built block stage 1 or 2. If you plan on using E85 at 350whp, the RA block would be fine for your needs. But if you are then kind of person who will want more power a year later, then build the block for the future.
Thanks for your input. Yea I will be that guy that will probably want to push the motor to go faster. Currently, the stock vf52 pushes about 20psi for both the 93 tune and E85. From what I read, thats pretty much where the efficiency of the turbo is so if the car was in top shape fully running E85, the turbo wouldve been my next 'upgrade' for engine performance- but thats where we start to hit the limit of the engine itself.
If I opt to get the STI EJ257 short block, will my WRX heads and supporting parts bolt right up to it? Sorry for the noob questions.
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Old 01-19-2021, 12:44 PM   #6
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yeah the STI short block bolts up- it's very similar- you'd have a slight change in compression as a result since the Sti uses different cylinder heads.

also the sti has an oil cooler and yours doesn't- but that just means you need to buy the plug from subaru.

And make sure to get a WRX water pump.

https://forums.nasioc.com/forums/sho....php?t=1667168

EJ257 pistons on B/V25 STi head: 8.28:1
EJ257 pistons on D25 WRX head: 8.78:1

EJ255 pistons on D25 WRX head: 8.55:1
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Old 01-19-2021, 01:31 PM   #7
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yeah the STI short block bolts up- it's very similar- you'd have a slight change in compression as a result since the Sti uses different cylinder heads.

also the sti has an oil cooler and yours doesn't- but that just means you need to buy the plug from subaru.

And make sure to get a WRX water pump.

https://forums.nasioc.com/forums/sho....php?t=1667168

EJ257 pistons on B/V25 STi head: 8.28:1
EJ257 pistons on D25 WRX head: 8.78:1

EJ255 pistons on D25 WRX head: 8.55:1
Thank you! Im leaning towards to maybe just getting the RA short block. I talked to someone at Import Image Racing (IIR) and they recommended also replacing intake cam gears to avoid metal shavings on the new block that might not get cleaned out. Can it really not be cleaned out and reused?
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Old 01-19-2021, 02:11 PM   #8
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I'd suggest doing that as well. I'm about finished building mine- cleaning the intake cam gears out was quite a bit of work- and I've got a parts washer and everything. It's worth the money unless you really like to tinker with everything to buy new ones.
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Old 01-19-2021, 02:20 PM   #9
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to give you an idea of what lurks in there. and showing the parts cleaner shot so you can see all the holes that can hide metal debris.
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Old 01-19-2021, 03:10 PM   #10
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to give you an idea of what lurks in there. and showing the parts cleaner shot so you can see all the holes that can hide metal debris.
Seem like it could be a tedious job cleaning them out, huh. I will see how the condition of the motor once I tear it apart.

Eric from TP said the log looked fine when I did the last 3rd gear pull where it started knocking. He said most likely I lost oil pressure that caused it. I read the log and noticed that even before the pull, the LS AVCS stopped advancing the intake cam where the RS was working normal. It was still working on a small WOT from 3k-4k that I did prior to the 6k pull. Dont know if that had anything to do with it, but everything else looked good. I has a very noticable knock now at around 2k rpm and goes away as it climbs and not noticeable during decel. Oil pressure at idle is also very low as well (via pressure gauge).
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Old 01-19-2021, 03:52 PM   #11
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So unless you like working with your hands and have lots of patients, I would just get a new set of cam gears. After you put in a block that can hold 350 hp, don't forget about your tranny. The 5 speed can not hold as much power as the 6speed, so pushing over 400 will be gamboling with tranny.

Mixing heads with blocks will make your setup a hybrid. Read up on that, there are lots of threads on here about hybrids.
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Old 01-19-2021, 06:50 PM   #12
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it could well be that debris from the bearings had already caused the AVCS to seize and fail to change position and only when the wear got bad enough was a knock audible. Could also be that the bearing material just plugged the banjo bolt screen and then there wasn't any oil able to pushed through it to actuate the AVCS.
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Old 01-20-2021, 08:44 AM   #13
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it could well be that debris from the bearings had already caused the AVCS to seize and fail to change position and only when the wear got bad enough was a knock audible. Could also be that the bearing material just plugged the banjo bolt screen and then there wasn't any oil able to pushed through it to actuate the AVCS.
I was thinking this may have caused it. Maybe. As you can see from the screen grabs of the small RPM pull vs the 3rd gear full pull, the AVCS was working and then suddenly stopped. I was thinking that if timing had jumped that it would start idling rough, no? Regardless, damage was already made. I remember at one point of early ownership of this car reading up about the banjo filters. There were debates on which year, which models had the banjo bolt filters but
I dont remember anymore what I found on mine. I dont remember finding anything but then again, I dont remember if i checked all the bolts.

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Old 01-20-2021, 06:07 PM   #14
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I checked the LS AVCS banjo - no filter


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Old 01-20-2021, 07:23 PM   #15
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Left side is usually behind the timing cover
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Old 01-20-2021, 08:13 PM   #16
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Left side is usually behind the timing cover
That picture is the one behind the timing cover
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Old 01-22-2021, 08:04 AM   #17
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Ok Ive been pricing things out.

From Import Image Racing, with the RA block, oil pump and new cams is only about $200 cheaper vs if I was to purchase a bare block, nitride crank and their build package '1B' with Manley Rods/Pistons. I used to be a technician back in the day and went to school to be a certified toyota tech so im capable of putting the parts together if it yields a better result than just getting the RA block.
What do you guys think?
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Old 01-22-2021, 08:55 AM   #18
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Let the experts do what they do, that's not a big price difference.
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Old 01-22-2021, 10:34 AM   #19
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Don't forget to factor in any tools you need to buy in any calculations.

Built isn't always better. At your power levels, just go with the RA block and probably get more miles in before needing another rebuild.
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Old 01-22-2021, 10:41 AM   #20
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Quote:
What do you guys think?
This question is hard to answer, since we do not know your skill level of eng assembly, what tools you have, your budget, your plans for the car, how you drive, ect... Keep in mind, not all build blocks should be the same. A built block needs to be assembled to what it will be used for. Getting a " off the shelf" built block should not be used for Drag, or Rally, or autoX. They should be build to your specifications.
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Old 01-22-2021, 11:07 AM   #21
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This question is hard to answer, since we do not know your skill level of eng assembly, what tools you have, your budget, your plans for the car, how you drive, ect... Keep in mind, not all build blocks should be the same. A built block needs to be assembled to what it will be used for. Getting a " off the shelf" built block should not be used for Drag, or Rally, or autoX. They should be build to your specifications.
Totally understand your point. What I meant for the 'off the shelf built block' is using a new oem ej257 casing from subaru and using the build package using standard specs. Im just trying to consider the benefits of 'better' aftermarket parts (rods/pistons/bearings/etc..) vs just getting the RA block.
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Old 01-22-2021, 12:42 PM   #22
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You should have no problems with the RA block at your power levels. Its the track life that I'd worry about. Theres a few guys pushing 500whp+ but I don't know how much tracking they're doing.
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Old 01-22-2021, 02:21 PM   #23
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You should have no problems with the RA block at your power levels. Its the track life that I'd worry about. Theres a few guys pushing 500whp+ but I don't know how much tracking they're doing.
reading this article https://www.flatironstuning.com/blog...5-and-an-ej257
It states on there that the WRX head should not be used on an STI block.

"Because of the difference in piston dish and combustion chamber volume, it is not recommended to pair a D25 head with an STI block, or one that was designed to work with B25 heads."

Is this a matter of using the correct pistons? Again, sorry for the noob questions.
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Old 01-22-2021, 02:33 PM   #24
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Im sure they meant to say they are not direct bolt on. Need to change pistons, head gasket thickness, ect...
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Old 01-22-2021, 10:23 PM   #25
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However if you buy forged pistons they usually are the same dish volume as the STi and so will increase compression. Maybe they say that cause you’d need to tune differently to avoid detonation.
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