Stealth

iTrader: (4)

I have jsut bought an STI 9 bottom end to go in my STI 7 as I wanted torque of the 2.5 etc etc usual reasons really.

How hard is to do the change, as far as I can tell provided I take my time and pay attentino it can't be that difficult.... can it?? I'm not shy when it comes to taking things apart.

I'm trying to decide whether I should do the chop over myself, get a garge to do it or jsut sell the bottom end and stick with what I got if it's far too much agro.

I know it's a bit late to be thinking these things once I have bought the engine but it was a spur of the moment thing and seemed like a brilliant Idea at the time LOL

Thanks in advance

Sc0oby

just wait till the old engine dies before replacing it

TonyBurns

iTrader: (3)

Im confused so you want to (this is where it gets sooooo complicated when calling things STI XXXXX when its not) replace your 2ltr bottom end with another 2ltr bottom end?

Tony

eggy790

iTrader: (20)

i think he's replacing it with a 2.5 bottom end

TonyBurns

iTrader: (3)

Wont be an STI 9 then that "would" have been a twin scroll 2ltr bottom end (MY03) but they stopped doing versions at 6 due to this sort of confusion, and thats when all the issues will start (manifold, exhaust etc).

Tony

Butty

iTrader: (2)

Mr Helpful strikes again

Stealth - if you have the time, space engine hoist and correct tools then why not DIY?
The heads will need dishes matched to the bores and a remap before using in anger.

TonyBurns

iTrader: (3)

Its the joys of people calling things something its not, no real mention of using an STI 2.5ltr bottom end, just an STI 9 (something that doesnt exist), plus there are 3+ different new age STI bottom ends, model/year/size would be nice.

Tony

Stealth

iTrader: (4)

OK I will clarify ....... it is a Hawkeye STI bottom end 2.5 STI lump, which for all intense and purposes is classed as an STI9, search for STI 9 and that is what you get LOL..... Sorry for the confusion!!

Cheers Butty, I have the space, can get hold of a hoist and certainly have the time, have the wifes car to use when mine is off the road

Tony.... There was mention of a 2.5 lump in the first post mate.. .thanks for the bumps though

Splitpin

No, it isn't. This is another in the book of "Scoobynet myths regarded as fact". It might be referred to like that in certain circles maybe, but in truth that term means **** all (and if you're going to use numbers, 2006MY would be 12 anyway, not 9).

That's what Tony was getting at - and yes, while you mentioned 2.5 up top, given the JDM cars still being 2.0 you can see where the confusion arises. If you'd said "06MY Hawk 2.5 bottom end" or whatever to start with it'd have been clearer to everyone

joz8968

iTrader: (13)

Tony's right - Subaru dropped the "Version xyz" tag for the New Age STi cars. STi Version 9 (or IX as Subaru would have it) is NOT AN OFFICIAL Subaru moniker for the Hawkeye.

That said, Impreza fans do tend to 'affectionately' call the Bug a "v.7", Blob a "v.8" and Hawk a "v.9", as you elude to - despite it being wholly incorrect!

Splitpin

...which is where the inaccuracy and consensus misinterpretation starts.

Stealth

iTrader: (4)

Oh dear god..... clearly I'm not as die hard Subaru as I thought I was hey..... I now feel like failure :P

euurrrgghhhhh!!

Right then..... it's a Hawkeye 2.5 STI lump going in to a 2002 Bugeye.

Anything I should be particularly careful of? anything that will break at the sight of spanner ?

johngoulding

iTrader: (7)

not to sure if the heads will mate as most people have the heads machined ???

joz8968

iTrader: (13)

Totally.

alcazar

iTrader: (2)

I have it on VERY good authority from TWO sources that the 2.5 short engine is NOT a panacea for all ills.

It's better if you can afford to have it split, new decent bearings fitted and forged pistons. Apparently they have a habit of picking up a piston in standard form

AFAIK, the heads WILL fit, it's the head/inlet manifold and sensors that might cause trouble, but if you are using both from your car you ought to be OK

DO get the right gaskets and fit one that gives you the standard compression ratio

Are you going FMIC at the same time?

Stealth

iTrader: (4)

Thanks Alcazar, I'm not going to be stressig this engine I am only going to 450hp to start with and running 450ft/lbs of torque until I can source..... Nope, afford a 2.6 stroker kit and my MD321V

I already have the FMIC fitted

Neil..

iTrader: (35)

ERM, no.

I would do the transplant whilst your engine is healthy, and then sell it on.

Head machining is helpful, but not always neccesary.


As alcazar says, for over 400, I would definately replace the pistons.

If you are going for a 321V, then go for uprated rods as well.

For head gaskets, you can do no wrong by speaking to Mark at Lateral Performance for the correct size ones.

Stealth

iTrader: (4)

Brilliant, will make all required changes and buy pistons etc prior to new lump going in then, if i wont get away with more power than i have now on a std 2.5 i will take my time, get it all right first time around.

I'm doubtful my existing engine will go fizz to be fair, has a bloody good map on it, very safe as well, and the car has a very easy life

Thanks once again all, appreciated

Sc0oby

sti jdm unit have a better engine in my opinion ( not to start any arhument here) as it has better heads and bottom is better design than the 2.5

alcazar

iTrader: (2)

Mine is going only to 400/400 or so, and has already got the ACL bearings and forged pistons, plus it's been honed and polished where necessary.

My sources DO NOT recommend tuning that engine without doing the above first two parts.

bigsinky

hope you have lots of money or a very friendly bank manager

dazdavies

iTrader: (22)

Having swapped from a 2.0L STI 5 short block to a rotated garret GT30R fed 2.5 I can state the following.

The heads will be fine without machining just make sure you get the correct thickness gaskets I used 1.6mm OEM ones from RCM

I ran mine and 452bhp without issue but that was at 1.4 bar and I was prepared to sacrifice the engine. I would seriously consider splitting the block put some ACL race bearings in and get some decent rods and pistons. For little money the EJ257 block can be strengthened and will be able to cope with 600bhp and beyond. It will be a way cheaper than a stoker kit and produce the same power so don't waste your money with two sets of gaskets etc just drop in some rods and pistons now.

I've just gone that route with my engine, ACL bearings, Cosworth Pistons and Pauter rods. I'll be aiming for a shade over 600bhp when the time comes.

Have a read here for info and pics.

Stealth

iTrader: (4)

Sweet cheers Daz