97 engine swap

[m3f_tvellrath]

Hi,

I've got a 94 325i and I was thinking about putting an m3 engine in it. I know it probably wouldn't be too hard to put an OBDI engine in there from a '95 M3 but i was wondering if it was possible to put in an OBDII '97 engine. I'm pretty sure i would have to have a new wire harness and ECU but i was wondering if there was anything else i'd need like different motor mounts and sub frame. i'll probably get a 5-speed tranny from the same year too. I would really appreciate your guys advice. thanks

[m3f_Sirius_880bd69485]

They should just bolt right in.

[m3f_astan100_7ef66fbe89]

There is someone else on this forum (mazur) who is going to attempt the same thing himself...expect M3 3.0 -> M3 3.2.

[m3f_dapper83_ac01dd8204]

yeah it should work just a little more costly. Getting a new tranny is a good move cause from i ve heard the tranny in our car is lousy. Im doing a 3.0l swap would have done an obd1 3.2 swap had i had the money good luck with it

[m3f_beemertek]

I put an s52 in my 95 and there's not much that needs to be changed. If your car has vanos you don't even have to change the harness. Turner motorsports sells a coolant fitting that goes into the s52 head that a coolant hose connects to. The obd1 cars use two coolant sensors, one for the cluster and one for the dme. The obd2 cars use a dual sensor that has both in one. An o2 sensor connector will plug into this sensor. I cut an old o2 sensor harness and wired the four pin connector into the four wires that are on my obd1 harness. If you use the s52 exhaust manifolds you'll have to use the arresting valve and tubing that attaches to it to plug the holes for the secondary air system. If not the s50 manifolds will bolt up. You'll have to use the s50 valve cover because the obd1 ignition coil harness is ran different than the s52 harness. The newer valve cover might work, I just haven't tried to retrofit it. As far as the dme goes just buy an aftermarket chip for a 95 m3. I had problems using the newer dipstick with the s50 intake because the mounting points were different, so I used the s50 dipstick. I think that's about it. Everything else is the same. If you have questions ask. I'm running everything 95 but the longblock and exhaust manifolds.