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Old 03-22-2006, 02:41 PM   #1
azn2nr
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438/420 whp

Default soch rs heads??? and little blocks

Ive heard good things about the soch rs heads but not alot of people use them since everyone seems to use wrx stuff . The flow specs off of cobb's site seem promising but i havent found any info on the flow of wrx heads.

so after my reading i got excited and bought some. nothing fancy, used but still in pretty good condition. ive been searching for throwaway blocks that could be used in conjunction with these heads and havent found much. a different and stronger short block will be fine for later but for now i just want something to expriemnet on.

i recently pulled a 1.8 motor out of my impreza in favor of my ej22t from my legacy and got to thinking, how much power could i get out of a 1.8 block on some half decent heads. after all, a motor is just an air pump and alot of power is made by how well the heads flow.

would this project be worth taking on?
would it be possible to get about 350 whp out of this setup with a proper turbo and stand alone ect? (rotated kit (greddy or ultimite) and autronic + pe850)
what would the static compression ratio be when put together?
whats the best way to get bent lower studs on the back of the motor out and replaced?
how long would the 1.8 block last if pushed to the illlogical limit? (7500 rpms and as much boost as it takes to hit the 350 whp goal)

the short block has 155k on it and the miles on the heads are less than 100k.
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Old 03-22-2006, 02:44 PM   #2
Matt Monson
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Won't work. The shape and diameter of the SOHC Ej25 heads' combustion chamber will not mate up properly to either an Ej18 or an Ej20. You need to get to the bore of an Ej22 before it becomes feasible...
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Old 03-22-2006, 03:27 PM   #3
8Complex

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SOHC heads are not often used for higher HP applications because the valvetrain needs to be MUCH beefier as there is a lot more rotating mass in the head. The RS and WRX use almost identical valve springs, however the WRX can obviously push to much further levels because they are only working for the valves, not for the rocker assemblies and whatnot as well.
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Old 03-22-2006, 09:21 PM   #4
azn2nr
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more rotating mass??? hrmm 1 cam vs 2 cams. 1 cam gear vs 2 cam gears. seems to me that 1 is less than 2. wth are you talking about dude.

also why in good gods name did you move this here. this isnt a conversion topic. its a MOTOR BUILD question. this is not only asking which block to go with a given head but if a spesfic block will work to make a potent race engine good to 350whp

move it back, and while your at it bring back the thread about what happend to moose. or what, is this red russia in here. peeps get baned and we cant even talk about it.
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Old 03-23-2006, 01:55 AM   #5
ballitch
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although the wrx is DOHC, the valve springs only move the valves, not the rocker arms, the springs' sole purpose is for the valves, not valves and rocker arms. while the RS heads have half the cams in weight, the RS heads have more inertial mass per spring than the wrx heads do, see what im getting at? thats why you can spin them higher. get the titanium valve spring and retainer kit and your golden, bam, 7,000 rpms no prob.



~Josh~
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Old 03-23-2006, 10:51 AM   #6
Matt Monson
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Arguing about SOHC versus DOHC Ej25 heads is a mute point. They each have their advantages, and it's just one man's opinion that the SOHC heads are no good for serious power applications. I know people that spin the SOHC heads to 9000rpms. I also know people who push over 25psi of boost through them and make 450+whp. Even the infamous Rigolis have started playing with the SOHC EJ25 heads on some of their motors. You know the old saying, opinions are like *-holes, everyone has one...

And regarding you complaint about the movement? This isn't about a "built" motor. A stock bottom end with some different heads is far from "built". If anything this thread belongs in the AFI forum...
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Old 03-23-2006, 12:59 PM   #7
azn2nr
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i thought the bore of an ej20 was the same as ej22 as the 22 was a stroked version of the ej20. or am i way off here.
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Old 03-23-2006, 01:45 PM   #8
Matt Monson
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'73 914 and 2012 BRZ

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Other way around. the stroke is the same and the bore is bigger...
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Old 03-23-2006, 03:15 PM   #9
970subaru
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all those running ej22e bottom ends with "good" heads post up! whats your setup. azn2nr I hope this question is in line with your thread...
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Old 03-23-2006, 03:59 PM   #10
Matt Monson
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'73 914 and 2012 BRZ

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Give me a month- 6weeks and I will be...
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