cookstar

iTrader: (6)

I know pistons etc are different but is the block itself different to?



Cookie

impreza.dk

yes - it is!

It is a different block in design. The WRX block is a open deck design and the STI is a semiclosed deck and capable of producing more power.

Normski

The above applies to 'new age' cars.

AFAIK classic blocks are the same for Wrx's and STi's (jap imports). As you say, the STi's get the internal goodies.

geoff163

hi all,i never knew that either,i know the brakes and interior are different like.

cookstar

iTrader: (6)

so i would have the open deck then, can you have the blocks converted though, i have heard you can.

Just thinking way ahead here

brunny42

2.3 closed deck exchange block see andy forrest web site this may be your answer possibly

and what the hell does AFAIK mean i am not used to all the abrieviations any one

RedScoob

Converted? It's a different casting, I don't think that you can convert an open deck to a closed deck unless you replace the barrels (please call me an idiot if I'm wrong... ). I don't think it's too much of an issue unless you're after silly horsepower - the open deck design is pretty strong.

cookstar

iTrader: (6)

"As far as i know" = ASIAK i think


Dont you need lots of head work etc when upping cc?

brunny42

not sure i believe the original heads straight fit (tell me otherwise if i am wrong) but obviously porting polishing oversizing etc will benefit, but sure all original stuff fits on will need bigger turbo?? remaps fuel pump injectors yes so supose the list goes on and on but its all worth it for a torque monstor beast capable of huge power aswell and i believe the 2.3 is a lot stronger than the 2.5 andy f i think is around a 2.3 ish thats a monster under 10 sec 1/4 well we all know that.

LegacySTi

iTrader: (13)

Open deck block all classic imprezas except 93-96 Type RA which were closed deck. Correct if wrong.

cookstar

iTrader: (6)

all these options

Not thinking of doing something this big for a while, but would like to know what to aim for when i do take the plunge.

The 2.3 had not entered my thoughts yet though.


What power has been reliably produced with these blocks then

cookstar

iTrader: (6)

Also im assuming there must be some cons to having closed deck, like maybe cooling probs.

Prob wrong though

RedScoob

I thought that Ver 1 and 2 WRX and STi were closed deck with different internals for the STi? I've found conflicting data on this and am interested to know (I'm not taking a head off to look....)

brunny42

the power i think i read on andys web they produce more than the 2.5 and are more reliable, may be a load of rubbish?, but sure i read in scooby mags i get or web some where andys is 2.3ish also now on nos ?but god knows how often he rebuilds it but he is a wizzard with them,so no probs for him, i personally have had 2 classics fitted with apexi ecu by him and few other mods by me they were running 12.4 and 12.5 on the 1/4 mile constantly all day long about 16 runs in total each then drove home aswell at some strange high speeds, also they are used daily well were till 1 went the distance dont know on the pros and cons of closed deck never wondered TBH

jaytc2003

iTrader: (1)

The earlier wrx and sti both shared the same block just different internals. There is a "cross hatching" mark on the block which indicates that it is a closed deck block. There was a post on here a few weeks ago about identifying them, and there is also a picture of the markings. David @ API confirmed it.

APIDavid

iTrader: (4)

Oh Dear, Oh dear, Lets try to put some perspective in here.

Legacy turbo is mostly Closed Deck block [CDB] which was what was used for the first production run of Impreza. Early WRX RA had CDB as part of its spec and this continued up to STi vers 2 RA where it starts to become unclear. Standard WRX is open deck block [ ODB] from about 1993 onwards.

Vers 2 RA should have CDB but some we see here are not. Possibly because the engine has been replaced at some time. OR maybe it's when the CDB stopped being available. Vers 2 Sti and RA should also have shimmed buckets on the tappets but many don't. Ditto Red inlet manifolds.

ODB continues throughout the GC8 until it finishes in 2000.

Semi Closed Deck [ SCD] is on the new age cars and is open deck with just small strengthening ribs on the open side locating the cylinder better to the block sides.

These are facts. Because of the chance that engines have got changed it is possible that a number of you have something different.

Because of the sheer number of engines we see here, these details can be supported by sheer weight of evidence.

Like all / many things Subaru, there is a lot of folk lore that tends to get distorted over the years.

Hopefuully I have set a few things straight for you.

David APi Engines / APi Impreza
www.apiengines.com

RedScoob

Thanks for clarifying, David.

cookstar

iTrader: (6)