I am a new forum user and this is my first post. My two sons and daughter have owned collective eight 325’s, and I have served as chief mechanic and advisor. I currently have a 1986 325e project, my youngest son drives a 1987 325is, and a 1991 325i parts car. I have a total of 4 complete motors to work with, two 2.7’s and two 2.5’s. Two are out of the wrecking yard and all have some problems the current project involves a complete rebuild of the 86 2.7L motor. I’ve decided to modify the 2.7 with 2.5 head etc. or swap an entire 2.5 motor. My question is what parts from the 2.5 can I use on the 2.7 that will increase performance above just swapping an entire 2.5. I know the heads will swap directly and form the looks of it the 2.5 intake and throttle body should also be used since it is larger and the ports will match. My other questions are
1. What computer chip or entire ECU should I use?
2. If I use the 2.7 I will need a new set of .020 over pistons, I’ve had trouble finding a source for less than about $1200.
3. Will a 2.5i motor bolt directly into the 325e body.
4. Is the 2.5 just a de-stroked 2.7 block, they both share a 84mm bore.
Any help with this is appreciated.
1. What computer chip or entire ECU should I use?
2. If I use the 2.7 I will need a new set of .020 over pistons, I’ve had trouble finding a source for less than about $1200.
3. Will a 2.5i motor bolt directly into the 325e body.
4. Is the 2.5 just a de-stroked 2.7 block, they both share a 84mm bore.
Any help with this is appreciated.
