Hello i have bought a sti ra and the big ends have gone on it,i have a block of a wrx and was wondering if its ok to take heads of sti and inlet and use the wrx block?

 

i think i'm right in saying the sti block has better pistons and possibly rods??

so if your using the wrx block might be best to fit the sti pistons and just replace the bearings at same time while engine is out.

but if you just want to drop it in there should be no problems

 

can anyone tell me more about the 5th injector?? am confused lol

 

it's a 5th injector on the inlet that doesn't do anything.

 

and if it's got one of them I'm assuming it's a V1/2 and therefore has a closed deck block, so going to a WRX block is a downgrade, regardless of pistons. That said, you probably will never notice a difference at standardish power.

 

and if it's got one of them I'm assuming it's a V1/2 and therefore has a closed deck block, so going to a WRX block is a downgrade, regardless of pistons. That said, you probably will never notice a difference at standardish power.

 

Your RA block more than likely has the under piston squirters, CDB is stronger, fit what you have ie the wrx short block, save up and get a good forged build done on the CDB.

5th injector was put on for Homolgomation purpose but is not connected to the ECU

 

I think it is connected but doesn't do much. There's a wire going into the loom off it anyway lol.

Good plan with the cdb

 

If it's a CDB it will be pretty obvious from the outside because it has cross-hatching which the normal block doesn't particularly on the oil filter mount. Under piston sprays are nice as well. Definitely a better basis to do a build from.

 

cheers for all that info.Would i be right in sayn that sti ra shud have red inlet or is that just sti? This one i hav is just silver....

 

No, STI2 has a red inlet, but STI RA 2 doesn't for some bizarre reason. STI RA 3 has one.