Heads VS Heads
 

All,

Im having some trouble ascertaining information about various pros/cons/specs of GD heads.

The heads I have (V7 Sti) are small port, when compared to 03-05 heads apparently?? And as I dont fully know/understand the various shimless/shim over/under bucket designs, what is preferred in my application?

The car made 330h/395n previously at the hubs, and I want something that will sustain this (and more this time around), reliably. Keeping in mind bottom end will be 2 to 2.35L, am I better off keeping my heads, with 264 or 272's in them, or getting 03-05 wrx/Sti AVCS heads?

Am looking at sustaining up to 2 bar. So on advice have selected Cosworth head gaskets and 11mm studs to withstand. Anyone with the nousse (spl?) want to input?

Thanks in advance...

Brent.
:)

your 02 sti heads will be more then adequate, they already have avcs.
likewise stick to the standard sti head gaskets
just go the normal ARP replacement head studs for an 'upgrade'

invest in some wideband for tha motec of yours :)

Yep, there will be absolutely no trouble with your heads.. just get em cleaned up nicely and ported if possible. You're already shimless too, so no need to worry about shim over/under bucket.

Sean's car made over 500 on his MY98 WRX heads, ported of course, with big cams..

You should be fine if not chasing crazy power and not big big boost... You can make anything flow good by doing this...

Cheers lads...

I was asking because of advice received from MSR, (below), means the bottom end would be all tickedy-boo, then its just a case of getting the heads serviced, new cams and associated bits, and piecing it all back together:

[I]Hi Brent,

I can use your bottom end and put another crank and set of rods in it, hone, recoat the pistons skirts, spec c rods, crank with my oiling mods, bearings, coat pistons, rings, assemble, hose, deck blocks. Can freight it back for 100, sent a few over there.

If you can pull it right down, just send cases, bolts, and pistons, oil cooler would be 2 boxes on Aust post .

264's is as big as i would go, issues are the small port heads[B]???[/B], if you can find a set of 03-05 wrx avcs heads they are big port, cams in those, they are shimless buckets too.[/I]

It does make me want to head this way. Seems fairly hassle free, once I can sort the other niggles out:

* Stace, on your reply, would you recommend OEM over Cossie head gaskets? :confused:
* Will the Sti OEM 10mm oil pump be enough? (New one I meant)
* Finding L19 11mm Cossie head studs.
* Finding a solution to the 264 vs 272 debate.

Trying to find enough info, regarding power/safety, where in the rev ranges this power is going to come on, ease of tuning, reliability, and lastly, (although not of uber importance - economy... :D)

Stace, I already have WB unlocked... And a Bosch LSU 4.2 sensor in the pipe... You know this. ;)

Sigh... but things are moving in the right direction.

Brent.
:)

i'd stick to the oem gaskets, the failiure point on them is fairly acceptable, i cant see cosworth being realistically any better.
i'd recommend an overdriven oil pump if possible, the cosworth/jun one.
the standard replacement cosworth (ARP) head studs are cheap anway between $2-300
i'd also go the cosworth 278 avcs cams, cheap enough and will make decent power, theres not a lot of options for aftermarket avcs cams.
re-wideband, true- i forgot :) but at least we can make it safer for you!

Weird.. not sure about the 03-05 WRX head thing, I would have thought the 02 STi heads are at least the same, being AVCS and all? They're also shimless buckets afaik.. so not sure what he's referring too.

12mm STi oil pump or Cosworth high flow pump would be my choice.

Hmm... so apparently 03-05 WRX heads ARE big port heads, 02-05 STi heads are small port. WEIRD! Just did a Google search and all info points to that.

Either way, I don't think you're gonna have too much of an issue with your heads, running decent size cams (272's mate, DO IT).. make sure you port and polish!

Like I said, Sean runs MY98 WRX heads, and Tino runs STi ("small port") heads, albeit modified. They both have big boost and big power, so I don't think you're gonna have a problem with them.

Some interesting info for ya too..

[url]http://www.wrx.com.au/forum/viewtopic.php?f=6&p=737261[/url]

[QUOTE=BALISTC;488607]Hmm... so apparently 03-05 WRX heads ARE big port heads, 02-05 STi heads are small port. WEIRD! Just did a Google search and all info points to that.

Either way, I don't think you're gonna have too much of an issue with your heads, running decent size cams (272's mate, DO IT).. make sure you port and polish!

Like I said, Sean runs MY98 WRX heads, and [B]Tino runs STi ("small port") heads, albeit modified[/B]. They both have big boost and big power, so I don't think you're gonna have a problem with them.[/QUOTE]

Yes i started off with small port heads but theyve been enlarged considerably so i [B]would not use[/B] this as a valid comparison..

Seans runs big boost though so also take that into consideration...

Big boost makes power albeit not efficently... just ask rigolis... they dont care about head work..