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Old 10-10-2012, 05:35 PM   #1
fullCircling
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Default What heads for 2.5 high compression street build? Anyone make NA dual AVCS cams?

First of all, does anyone make any dual avcs cams that would be good for an NA application? How about single AVCS?

I threw a rod in my stock ej25d (97 legacy gt), so I picked up a 257 block that needs pistons. I'm gonna put in a set of high compression CP pistons, but I still don't know what heads I wanna use. I still have the stock ej25d heads in the car that I hear aren't too bad, flow wise...

...but... I'm gonna convert the car to use dual AVCS at some point. Right now I'm prob just gonna go high compression NA while I get parts together for a turbo setup.

Soo, if you could point in the right direction as far as heads/cams, and manifolds I'd appreciate it.
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Old 10-10-2012, 05:36 PM   #2
fullCircling
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Can I go 100mm bore on a 257 and still have room for another bore later on?
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Old 10-10-2012, 05:37 PM   #3
dangerousatom
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07^ 2.5i head are AVCS and flow better then WRX or STi
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Old 10-10-2012, 06:20 PM   #4
Counterfit
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No, 06+ are AVLS heads. AVLS and AVCS are different.
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Old 10-10-2012, 07:13 PM   #5
fullCircling
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o.0 ...really?

so even if i swap out the pistons and go turbo later on, which i definitely will, will converting to AVLS still be better (as far as power/driveability/cam options go) than converting to dual AVCS?

lol are there even any aftermarket cam options for them?
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Old 10-10-2012, 07:23 PM   #6
fullCircling
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waitwaitwait this: (AVLS)...?
(controls valve lift, pretty much like hondas vtec)
http://drive2.subaru.com/Spring07_whatmakes.htm



flows better than this?
(controls cam timing, pretty much like i-vtec without the variable valve lift... right?)
http://drive2.subaru.com/Win05_WhatsInside.htm
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Old 10-10-2012, 07:33 PM   #7
Counterfit
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I'm not making any claims as to what flows better.
Quote:
Originally Posted by fullCircling
lol are there even any aftermarket cam options for them?
Yup. Delta has them available. AVLS has only been in the US for 6 years...
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Old 10-10-2012, 08:28 PM   #8
fullCircling
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cool, ill give them a call and see what they say
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Old 10-14-2012, 02:49 PM   #9
JRVmotorsports
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Default Sorry to hitch hike your thread , But I need help

Just joined the site , and they won't let me start a thread until I have posted on other threads first . Sorry again !!

I race a class 5 Unlimited desert car with tons of race wins and 5 total championships , We run an unlimited displacement VW style type four engine modified to the moon , starts out as a 2.0 ltr and now is well over 3.0 liter and makes close to 350 hp with a motec 800 engine managment system , This is a $36,000.00 engine package that must be gone thru every race. Due to this situation there have been some recent changes to our class rules

I can now build a Subaru naturally aspirated engine package at 2.5 ltr. max and maybe get a few thousand miles before a rebuild instead of one race . So this is where you guys come in . There are tons of Turbo race engine builders out there , but as soon as I start talking about pistons , camshaft profile , ect. they start to get crazy . I need help to figure out what 2.5 model will be the best to build aspirated . and if you guys can help me find a engine builder that has experince Subaru N/A race engines it would be way appreciated
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Old 10-14-2012, 03:04 PM   #10
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^ Lawl, that doesn't mean you threadjack. You should post in some useless threads in OT and then you can make a real thread.
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Old 10-14-2012, 03:18 PM   #11
JRVmotorsports
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Quote:
Originally Posted by chazly413 View Post
^ Lawl, that doesn't mean you threadjack. You should post in some useless threads in OT and then you can make a real thread.
No offense intended
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Old 10-15-2012, 01:16 AM   #12
dangerousatom
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Old 10-15-2012, 02:53 PM   #13
Patrick Olsen
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Quote:
Originally Posted by fullCircling View Post
so even if i swap out the pistons and go turbo later on, which i definitely will, will converting to AVLS still be better (as far as power/driveability/cam options go) than converting to dual AVCS?

lol are there even any aftermarket cam options for them?
lol AVCS offers advantages for turbo spool. lol
lol

Quote:
Originally Posted by fullCircling View Post
waitwaitwait this: (AVLS)...?
(controls valve lift, pretty much like hondas vtec)

flows better than this?
(controls cam timing, pretty much like i-vtec without the variable valve lift... right?)
You are correct that AVLS alters lift while AVCS alters timing.

And the method of cam actuation has nothing to do with the flow capability of the heads. I have no idea which heads flow better (STI vs WRX vs EJ25D vs EJ251 vs whatever) - go do some digging in the Built Motor Discussion forum to find that sort of info. Really, this whole thread belongs in that forum.

Pat Olsen
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