2.7 - 2.5 part swaps

[E-Z]

Ok so I know the 2.7 head is average, but in not looking to change that as of yet, what I'd like to know first is if I can run a 2.5 ecu on the stock engine? Or will I need to swap in the 2.5 intake aswell?
Also can some one difinatively tell me in CCs the size of the 2 engines injectors?
Thanks

[jlevie]

No, you can't use the DME from an M20B25 engine on a stock M20B27. To do that you'd need to install the M20B25 head, intake, injectors/FPR, AFM, engine harness, and CPS.

[E-Z]

Why?? I understand everything but the head.

[TheTacoMan]

http://www.strictlyeta.net/technical/328i_1.html

[E-Z]

i understand all that, let me give you more details maybe it will help. im turboing my stock b27 (budget build from another forum not changing heads)
and i want to run the better ecu, bigger injectors etc which is easier with the b25 electrical side, will it work on the b27 head solong as everything is is b25 spec? esentially it will make up for smaller valves and stuff with the displacement
im going for mass torque down low. HP figures and RPM has no influence at all on this build

[JasonBates]

From what I understand, you the head is designed to be a low revving head. So it wont be able to take the added strain of the high revving ecu.
It doesn't flow as well and any 'i' head either.

This page helped a lot when I was looking for info on a head swap.
M20 Engine Specs

[E-Z]

correct, it doesnt rev because it has single valve springs which valve float at higher rpm, and less cam bearings so longevity with rpm is an issue.

mine is a 1987 with motronic 1.1 325e, i think it will work fine with boost actually