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Old 08-17-2007, 04:56 PM   #1
BallzToTheWallz
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JBP 306 whp 366wtq

Default 2.5l hybrid questions.

Im putting a ej257 block on my ej20 heads and i purchased cosworth stage 2 cams. Has anybody ever done this before? Somebody told me it would mess up the motor but i dont see how it would. The only thing i could think of is the valve/piston clearance which i will check.Is there anything else i should worry about?

Another thing is the extra oil port on the 2.5 block what do most people do with this should i just plug it or would that be bad for the motor too? If not then what would everyone recommend i do with it?

Any information on this swap is helpful and needed.

If anybody has done a swap like this, are there any problems i need to look into before assembling the motor.

Thanks alot guys your help appreciated.
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Old 08-17-2007, 06:18 PM   #2
Acostafan
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Default

I am not sure about the cams, but I would think they would be OK. As for the oil port, it has been the subject of much debate in this forum. Nobody seems to really know what to do with it. Many, including myself have blocked it off with zero issues, but some run a breather on it. I will probably do that soon just to be safe, but as I said, many run it blocked with no problems.

As far as your build goes, it is essential that you buy a Subaru Factory Service Manual. You can get them on Ebay all day long for 15 bucks on CD-ROM. You will need it for torquing order and spec for the heads among other things. Everything bolts right up, but make sure you take your heads to be checked and machined if necessary. IMO, it is best to run the stock STI head gasket versus a Cometic. Also, depending on your mileage, you may also want to have the valve lash checked and set if necessary.

Research, research, research. Take your time and give the project the love it deserves. If you have any questions, ask away. Good luck!
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Old 08-17-2007, 07:00 PM   #3
javastiwagon24
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bump "i blocked mine too" heard that breathers make it run too rich or lean "cant remember"
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Old 08-17-2007, 10:47 PM   #4
charliew
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Default Breathers

Walk around the block briskly one time. Now do it with your nose partially closed off. If a high performance motor comes with an extra breather it's there for a reason. On high performance engines people even put on vaccum pumps to help ring seal and to remove crankcase pressure.

Charlie
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Old 08-22-2007, 02:12 PM   #5
WRXbluJ
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My breather hose is T'd back into my catch can. charliew is right, it is there for a reason.
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Old 08-25-2007, 12:42 AM   #6
bakka
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i have the same set with stage 3 cams.The car is abeast.
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Old 08-28-2007, 06:48 PM   #7
MindzeyeWRX02
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The upgraded cams will get you good results in the top end.
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Old 08-29-2007, 03:59 PM   #8
jonhybrid
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Quote:
Originally Posted by javastiwagon24 View Post
bump "i blocked mine too" heard that breathers make it run too rich or lean "cant remember"
Why would it make it run rich or lean?
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Old 08-29-2007, 05:04 PM   #9
gregor2001
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The only thing I would add from what I have learned (just into the hybrid process myself) is that you would probably want to go with a thicker head gasket to keep the compression down in the 8.2:1 range. I believe that EJ257 + WRX heads with oem gaskets would be somewhere in the 8.7:1 - 9.1:1 range?

Last edited by gregor2001; 08-31-2007 at 12:29 PM.
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Old 08-29-2007, 09:24 PM   #10
Acostafan
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Quote:
Originally Posted by gregor2001 View Post
The only thing I would add from what I have learned (just into the hybrid process myself) is that you would probably want to go with a thicker head gasket to keep the compression down in the 8:2 range. I believe that EJ257 + WRX heads with oem gaskets would be somewhere in the 8:7 - 9:1 range?
Not an issue if you have a good tuner. Better around town driving with the higher CR. I'm running the stock STI gaskets and love it.
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Old 08-30-2007, 10:51 PM   #11
BallzToTheWallz
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She'll be done on Saturday. I cant wait!!!!!! What kind of numbers do these hybrids make on the dyno?

Ill be running
ej257 shortblock
ported and polished heads
crower stage 2 cams
crower valve springs
crower titanium retainers
ferrea valves and valve seats
Vf22
575cc power enterprise injectors
perring fuel rail
full exaust headers back
Turbo XS FMIC
AEM short ram intake
ARP head studs
and w/e else i forgot. I wanna hit the 350 range on 93. Is that reasonable?
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Old 08-30-2007, 11:46 PM   #12
bakka
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overkill for just 350 .High compression makes avery aggressive car on and off boost
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Old 08-31-2007, 03:20 PM   #13
MindzeyeWRX02
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Quote:
Originally Posted by Acostafan View Post
Not an issue if you have a good tuner. Better around town driving with the higher CR. I'm running the stock STI gaskets and love it.
+1, i am also using the STi HG and running a higher CR. Just get tuned for it. I would rather solve the issue with a tune then a HG.
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