Shaks-STI

iTrader: (7)

i was surprised to read that they dont rev to 8000rpm because mine does and pulls well up to 8000rpms. I am not saying that im running crazy power to justify much but for a road car running 366/380 im happy with how the engine revs to the redline and pulls all the way.

Kwik

iTrader: (10)

Ah! So your current project is not your swan-song then?

jme-rst

i also noticed how the ej20s seem to drop early in the rev range at usually between 5500-6500k even stis.

so revving any higher wont do anything more.

i want to do a cdb 2.1, am hoping the torque increase should give it a bit more pull higher up the range.
if not will be looking at headwork and possibly aftermarket cams to get the engine to rev more.
id prefer a more lively/revvy engine over a flat powerband as such

Kwik

iTrader: (10)

From what i understand Version 3 STI heads are the one's to have for a 2.1, its just finding ACTUAL V3 STI heads that is the problem. My std 94WRX runs out of steam at 6k, so what the 2.1 will rev to i'm not sure.

banny sti

iTrader: (68)

2 litre



2.5s

Kwik

iTrader: (10)

What's the bottom graph Banny?

jme-rst

you are spot on there fella,they are the ones that everyone says to get,but as you say the trouble is finding them,and who is to say you are actually getting v3 sti heads,is there a noticeable difference in looks?

have been looking into aftermarket cams,only a mild profile though and uprated valvesprings/retainers etc.possibly oversized inlet valves also
and having the head ported/polished and tested on a flow bench.

Kwik

iTrader: (10)

Well the STI V3 heads have "wilder" cam's which i take to mean they have higher lift. There's about 4 parts to recognise them, lines on cams, right lettering on cams/valves and whether they are shim under bucket. I found a set which had 3/4 of the right parts/markings but they aren't shim under bucket.

MartynJ

The problem guys is, it's all relative.
A 2 litre or 2.1 engine with a 500bhp turbo will rev higher than a 2.5 fitted with the same turbo/heads/ due to the VE of the engine.
A 2.5 absolutely can rev, but in my experience needs much more money throwing at it to get it to do so, headwork/cams etc.
The right setup can work really well, but on a pound for revs basis (If you want to look at it like that), I think the 2.1 is hard to beat !

banny sti

iTrader: (68)

Kwik it was a 2.5 with an MD321T

some info about heads for you guys

http://bbs.22b.com/forums/showthread...ight=sti+heads

http://bbs.22b.com/forums/showthread...ight=sti+heads[

dazdavies

iTrader: (22)

I might build another engine but I'm not building another car!

dazdavies

iTrader: (22)

Standard 2.5 Casings that have pinned inserts around the bores.

s5ooob

iTrader: (1)

Daz, can I ask, where you had the block pinning done?

in your opinion, are the cnc inserts a stronger solution?

dazdavies

iTrader: (22)

My pins were done via an engineering company that zen use.
They've proved good enough for me so far.

Alyn certainly knows what he's doing I'd happily use his insert solution too.

toyney83

iTrader: (3)

thats some going that daz, 600bhp on standard liners. Heard some horror stories about 2.5 liners ballooning at over 500bhp

legacy_gtb

iTrader: (3)

"thats some going that daz, 600bhp on standard liners. Heard some horror stories about 2.5 liners ballooning at over 500bhp"

Thats what the pins are there to reinforce against arent they?

Kwik

iTrader: (10)

Thanks Banny. I think i'll stick with my search for genuine STI V3 as i've just about put together what 4 things identify them. As i say i came very close, 2 lines through the cam's, right codes on the cams, right codes on the valves, they were just shim over bucket rather than under.

My head hurts....

Kwik

iTrader: (10)

That's my understanding, making it semi-closed deck rather than open. I wonder what the cost of having them pinned is.

I guess the big question is why did Subaru move away from CDB?.

matt-c

iTrader: (5)

CDB more costly to manufacture, more prone to failure in manufacture.

Different methods used for CDB / ODB manufacture - IIRC

toyney83

iTrader: (3)

pinning the liners helps prevent hg failure. Not sure it helps reinforce the liners which are notoriously thin

legacy_gtb

iTrader: (3)

Its all kind of one and the same thing toyney! The HG fails because the liners deform, and the liners crack because theyre deforming! therefore pin the block, reduce the deformation, stronger liners and more stable HG's.

The liners have a wee cutout which ive never understood! If you look on the right hand liner on the pic of the pinning, at 11 o'clock and 7 o'clock, youll see a wee depression which seems to serve no purpose! its not needed to get a tool in and isnt something which would be required for manufacture ..... so whats it doing there? All the cracked liners ive seen have propogated from this wee depression!

dazdavies

iTrader: (22)

Ive done 10,000 miles and circa 40+ quarter mile runs with this block and its in great nick.

toyney83

iTrader: (3)

good stuff daz, might be interesting to take a deeper look into a built 2.5. Would you say a cdb conversion would do as good a job as pinning?

Kwik

iTrader: (10)

Those depressions are also on a CDB and i found i needed them when taking my block apart as i needed to use a gripping socket as one of the bolts was corroded due to the engine having water rather than coolant in it.
Its definately made for function, but if they are also on CDB's they can't be at fault for the problems 2.5's apparently have.

toyney83

iTrader: (3)

Well it's taken almost a year to make my mind up, but I finally bit the bullet and decided to go the 2.1 route. The block is currently down in Plymouth with Alan and his boys getting built up

ditchmyster

iTrader: (7)

Wise decision.