Rebuild or engine swap from m54b22 to m54b25

[AndersFIN]

Hi!

i have just purchased a 2001 Z3 for my Rebody project.The engine is a hydrolocked M54B22 with 160000km milage with Manual gearbox.
I have been looking into the option on either rebuilding the engine or than complete engine swap for 2,5 or 2,8. The smaller might be the option I choose as they are much easier to find at lower cost.
Questions:
- Can I use the same ECU on both of these engine options and do a remap?
- Are engine auxilleries similar compared to the B22?
- Any modification needed for the gearbox?
- Any known mods to do for the 2,5 to reach more horsepower from the original 192bhp?

 

[andyglym]

to the Forum from West Cumbria. Other more technical folk will be along to advise, that aside, the 2.8 is an M52, it's the 3.0 that's the M54.

 

[Zephyr]

As already mentioned, the 2.8 is an M52
for the rest of the questions
yes
no
yes, but not a cheap job. m50 intake, with plugged ICV, headers and filter box will ad 25hp tops. Put a 3.23 diff in the rear, it will feel quicker and may be cheaper.

 

[AndersFIN]

Thanks for your responses.
Which engine would you prefer for the swap?Is the low-end torque so remarkable on the 2,8 so it’s worth to look into?
So Sephyr,you mean that I can not use starter motor,alternator etc from my existing motor for the swap?

 

[Zephyr]

To be 100 sure you have to search parts cross reference at www.realoem.com
put your vin there and browse through the parts you are interested.
if they are cross referenced, they will fit.
Sometimes, M54 engines have the same parts but with different mounting, so check beforehand.