Will Version 4 STI heads fit an STI 8 short motor? And will the gearbox marry up to that sti 8 motor? Any help or info will be much appreciated

 

Will match no problem on both counts. Just make sure you use the correct headgaskets to keep your compression ratio correct.

 

Good, How would I kno which head gaskets to use? I don't kno much about that sort of thing. So to confirm cos I'm thick...........my heads will fit therfore my inlet manifold will fit, and my gearbox will fit, I can basically use all my original stuff off my V4 on the new sti 8 bottom end??

 

yep thats what im just about to do as my sti4 shortblock has just done a big end.
not sure on the gaskets tho,but the genuine subaru ones are a must i am told.

 

Need to find out which gaskets to use now so the comp ratio's are correct........could be difficult cos I havnt got a f-ing clue lol

 

you need to grid away one of the bolt holes under turbo that isnt used for mounting gearbox as the turbo water/oil banjo catches and doesn't fit flush. can post a pic tomorrow if it helps.

 

also the sti 8 block has a extra crank breather which can be blocked but i chose to tap it into the other one too.

 

You need to check if the heads have been skimmed etc and get the right size gasket or this could happen.
https://www.scoobynet.com/general-te...ease-help.html

 

Oh if u could put sum pics of it it would be a gread help mate! What would you use to block the breather hole up with?

 

not sure really which is why i kept it.

 

well i hope i dont get that problem!
someone highly recommended is doing the full build for me so hopefully i will be ok.

 

will try take photo of how much was taken off tomorrow as engine in car

 

What are you reffering to here mate?

 

the breather. instead of blocking it off i t'd it into my catch tank system

 

That pic is a great help mate! Ill get grinder out lol. What can I block that breather up with?

 

Ah right, what did you use to route it into the catch tank?

 

actually dont grind yet lol i think its the one to the lower left in fact im sure it is but will double check tomorrow and put pic up.

 

 

I cant say i blame you it certainly takes the stress out of it,sick as a pig wouldn't get close.

 

This is wheres cut off just been double checked as top one is top gearbox mount.
also how i did the extra breather.

 

Bloody hell, not as straight forward as I thort! Guna be sum headscratching at the unit wen I get this shortblock delivered! Any ideas as to what thickness head gaskets to use????

 

as said above you need to know if your heads are skimmed and work out compression ratio to get right size
http://www.chainganger.co.uk/Page2/Page2.html
i followed this to work it out

 

although it isnt mega critical as you will need a remap after anyway. i think i used 1.2 cometec gaskets and 14mm arp head bolts.

 

My heads are getting skimmed this week so that's taken care of. Is a re-map essential as I don't think I can map the ecu on my car??!

 

you ecu is not mappable mate.aftermarket ecu such as apexi etc needed.

 

Will it run on standard ecu until I hav enuf money for an aftermarket 1?

 

personally i wouldn't risk it. its alot of work if it wrecks it. ya could be ok if you drive off boost.

 

What's the reason for having a re-map if I'm just replacing the short motor? I can't get my thick head around it

 

all the jap cars are mapped for jap fuel (101 octane)
obviously we dont have that here,so if you are forking out for another engine it would be silly to run it on the lower octane fuel and risk det etc.
alot of the jap cars have been running on uk fuel without being mapped since they arrived in japan,and this is one of the main reasons you here of so many engine failures.