So its time

[moe30]

So I bought a 87 325e back in June. Replaced lots of suspension stuff, windshield and other boring stuff but it needed it. Now I'm wanting to start doing some research on building a motor for my e30.

I have read from time to time other peoples 2.7i builds and 2.5 swaps but I didn't hold on to it since I wasn't serious about buildling. Now after Christmas I've decided its time to build one.

Now for the info you might need.

87 325e 5spd. Bone stock. It has 194k.... oh wait thats what the 3 year old title says lol, my guess is probably around 300k since the od doesn't work so I will want to do everything fresh or atleast from a lower mile car.

The car will be a dd mostly.. it might find a track someday... but then again it might not lol. I don't need something that is super fast (boost not an option).

I'm looking for something that isn't going to take a ton of extra work. I'm wanting to stay with an M20 build just for the money. Also what are some good points to upgrade instead of going with just oem parts.

I appreciate everyone's knowledge ahead of time :D

[E30Gus]

I've been through what you are wanting to do now. I think most people on here will say to buy a lower mileage m20b25 (325i) and harness and slap that puppy in there. Take the head off and bring it to a machine shop for inspection/new valves if needed. Replace ALL of the seals on the bottom end so you aren't purging oil. OEM parts will are more than adequate for this build. Get a single mass flywheel, new clutch, timing belt, water pump, pulley, new head bolts. You will be able to use your current cooling system weather old or late style. I think you would be more than happy with the extra hp this engine will give you.

[moe30]

Now is the wiring different or will I just need a new dme and harness? Guess I'm asking will I actually have to cut into anything and reside anything?

Also did they put different transmissions in 325is' and 325e's? I always see people swapping the motors but never hear anything about the transmissions

[E30Gus]

I am pretty sure you will need a newer engine harness and ecu for the "i" motor to swap it to the motronics 1.3

The transmissions are the getrag 260 for the 325's. They are interchangeable with each other with the difference being the shift arm is either sheet metal plate or an arm. You will also have the sensors for the timing on the bell housing which you won't need after the swap (325e only). These sensors on the i engine will be off of the crank pulley (needing the 1.3 Motronics). Plug those holes so water doesn't get in there.

[moe30]

Now is the harness a plug and play deal or will I have to splice it into my existing wiring?

I'm just trying to see how much work I have coming, don't want to miss something lol. Sounds like I'll need the motor, ecu, harness and a 2.5 gauge cluster right?

Also if I decided to do a 2.7i build do I have to change the harness and ecu?