The comprehensive DOHC engine swap thread.

[free]

Ok, I have been trying to make sense of this thread. I have an 88 325ic 5 speed. what is the simplest way to put in an m50?

Can i use my existing transmission? If so, do I need a new driveshaft? If I need a new driveshaft, I assume it is because I have to move the tranny. if so, do I then need new tranny mounts? Pretty sure I need new engine mounts - e28 mounts bolt right up? Do I need a new clutch, slave cylinder,master? If I can keep my tranny, can I keep my 3.75 lsd diff?

Do I need a new radiator? I saw an E30 88 radiator and overflow tank listed on a swap parts list somewhere in the thread. I assume new hoses. Keep the E30 coolant temp sensor, all other sensors come from the m50?

325ix booster is a bolton and necessary?

[e30s52]

Free all these questions have been answerd throught this thread. If you need help with your swap I can lend a hand for a small fee. I am local and do nothing after school. Pm me if you are intrested.

[JRKOUPE]

Ok, I have been trying to make sense of this thread. I have an 88 325ic 5 speed. what is the simplest way to put in an m50?

Can i use my existing transmission? If so, do I need a new driveshaft? If I need a new driveshaft, I assume it is because I have to move the tranny. if so, do I then need new tranny mounts? Pretty sure I need new engine mounts - e28 mounts bolt right up? Do I need a new clutch, slave cylinder,master? If I can keep my tranny, can I keep my 3.75 lsd diff?

Do I need a new radiator? I saw an E30 88 radiator and overflow tank listed on a swap parts list somewhere in the thread. I assume new hoses. Keep the E30 coolant temp sensor, all other sensors come from the m50?

325ix booster is a bolton and necessary?

as e 30 said.all ans are here......


you can use your getrag 260...w/ your 3 73.....stock ds.


IX booster ........



or....... use from 320i or 944 using oe mc.

[FredK]

Porsche 944 brake booster. One post says that I just need to cut the rod and it will be good enough. Another post says it needs to be cut and rethreaded.

It needs to be cut and threaded. All you need is an M10 die and a hacksaw, and maybe some sandpaper, and you should be able to thread it fine.

[MR E30 325is]

It needs to be cut and threaded. All you need is an M10 die and a hacksaw, and maybe some sandpaper, and you should be able to thread it fine.

Thank you for the info.

[sushipower]

Never seen an 944 booster, is it thicker than the 320 booster?

[bykerboy]

I have read this thread multiple times and done some additional research and would like the experts here to validate what I have found about which driveshaft to us.

I am doing an M50 swap using the Getrag 250 transmission into my '89 325is. My understanding is the ouput flange bolt circle diameter (BCD) on the Getrag 250 is 78mm. The output flange on the Getrag 260 (from my 325is) has a 96mm BCD. Based on this I assume I can not use my e30 driveshaft. From what I have read the e30 318is transmission is a Getrag 240 with a 78mm BCD. I believe this is why I can use a 318is driveshaft. The only other thing I can not ascertain for certain is the bolt diameter on the 318is driveshaft. The Getrag 250 has 12 mm bolt holes and the Getrag 260 has 10mm bolt holes.

Does anyone know the bolt hole diameter on the Getrag 240 output flange?

Lastly, I have read on here that someone recommended a 318is driveshaft out of an automatic car. What is this?

Thanks....

[gregslow318i]

golden rule for the e30m50 trans question. use the drive shaft that came in the car the the trans came out of. so in your case the 250 came in the e36 (e36 trans are the same between the 325 and 318is iirc same with the driveshafts just looked on realoem) so use the e36 drive shaft w/a e30 gybo and a e30 center support. no need to swap flanges or have a custome drive shaft built.

I have read this thread multiple times and done some additional research and would like the experts here to validate what I have found about which driveshaft to us.

I am doing an M50 swap using the Getrag 250 transmission into my '89 325is. My understanding is the ouput flange bolt circle diameter (BCD) on the Getrag 250 is 78mm. The output flange on the Getrag 260 (from my 325is) has a 96mm BCD. Based on this I assume I can not use my e30 driveshaft. From what I have read the e30 318is transmission is a Getrag 240 with a 78mm BCD. I believe this is why I can use a 318is driveshaft. The only other thing I can not ascertain for certain is the bolt diameter on the 318is driveshaft. The Getrag 250 has 12 mm bolt holes and the Getrag 260 has 10mm bolt holes.

Does anyone know the bolt hole diameter on the Getrag 240 output flange?

Lastly, I have read on here that someone recommended a 318is driveshaft out of an automatic car. What is this?

Thanks....

[bykerboy]

golden rule for the e30m50 trans question. use the drive shaft that came in the car the the trans came out of. so in your case the 250 came in the e36 (e36 trans are the same between the 325 and 318is iirc same with the driveshafts just looked on realoem) so use the e36 drive shaft w/a e30 gybo and a e30 center support. no need to swap flanges or have a custome drive shaft built.

Thanks, now I need to find an e36 driveshaft as I did not start with a donor car, just the motor and transmission.

I'll scour the local junkyards first and then on to ebay!

[gregslow318i]

Thanks, now I need to find an e36 driveshaft as I did not start with a donor car, just the motor and transmission.

I'll scour the local junkyards first and then on to ebay!

I think I have one pm me if you need it

[MatRacer]

I bought an e30 with an s50 The speedo and the tach doesn't work.

Tach: An aftermarker tach was in the car and working when I bought the car, but i really don't like it. It was plugged on the black wire of the S50 ECU. Moreover, the black wire of the ECU is also connected to the black wire of the cluster. I think its on the blue plug, but i'm not sure.

To make the e30 325es tach work, what I need to do. I tough that eta e30 had 5k rpm, but mine has 7k...? What is the wire color/location of the tach on the cluster

Speedo: the speedo isn't working either. The car as a triple clutch diff from diff online with a z3 diff cover... What is the color/location of the wires for the speedo on the the cluster?


Any help would greatly be appreciated!

Thanks!

[etxxz]

^^
i suggest you look at the ETM wiring schematics. did you check that the plug on the diff is connected or even there..that works the speedo and its body harness. the tach (engine speed) is a black wire, pin 9 on your c101/engine harness. trace it from there i suppose. sounds like that car is a wiring nightmare.

Thanks, now I need to find an e36 driveshaft as I did not start with a donor car, just the motor and transmission.

I'll scour the local junkyards first and then on to ebay!

make sure the driveshaft has a 4bolt flange at the diff... some have 6iirc be carefull.

[MatRacer]

^^

Thanks!

I was looking in the bentley, But the wiring diagram of the cluster and engine is not as detailed than is the ETM.

I should be able to sort it out...

And yes, its a nightmare!

[e30_325es]

What o2 sensor is needed, if any at all? s50us with ebay headers in an 86 325es. Thanks!

Also, how do people mount the late model coolant reservoir in early cars? I see no mounts for it.

[etxxz]

primary (pre-cat) O2's always needed. your A/F ratio depends on it.