The comprehensive DOHC engine swap thread.

[2mAn]

Im a little confused by this coolant temp sensor that plugs into the head. I had a brand new one for my M20 motor that I never used, but its blue base and has two pins. It threaded right into the M52 head. My head also has two ports that I can thread a sensor into, and Ive read that since Im going with OBD1 I need two sensors. I plan on getting another sensor, but someone was talking about brown sensors.... like I said Im confused now. setup is OBD1 wiring from E34 and a M52 motor.

edit: just snapped a pic, maybe it will help. There is no 3rd drilled hole in between the two you see.



2nd edit: noticed the 2.5 stamped on the head, any chance I already have the M50 head and not a M52??? This motor has a questionable history

[kevvve]

Thanks for the help buddy!! Clears that up.

[golde30]

1 O2 sensor on the CAT. The 2 bungs on the eBay headers are for OBD2 setups.

[kevvve]

Question for those that have done m50 swap with ebay headers: how many o2 sensors are you guys running? And where?

[Ewills510]

Hi there I'm new to engine swaps I've replaced my m20b25 before but now I have a line on a m50 vanos motor out of a 1993 325is e36 what I would like to know is can I bolt this motor in as it sits or do I need to change any hardware on the engine to allow it to fit?

[P.Kelly]

Ok, so I'm confused a little on the exhaust I should run. I have a M50nv. I know the stock cast manifolds will interfere with the subframe, but i heard if I run the OBDII headers with plugged EGR it will clear. Will the stock e36 cat pipe (that comes on the OBDI motor) directly bolt up to the OBDII manifolds? If not, what other mods will I need to make?

I need the stock exhaust components to pass CA B.A.R. :(

Or, can I just modify the cast ones easily?

There are a number of people here who have gone through CA BAR with S50s and S52 headers without issue.

[drummerchubbs]

Anyone???

[drummerchubbs]

M50 exhaust

Ok, so I'm confused a little on the exhaust I should run. I have a M50nv. I know the stock cast manifolds will interfere with the subframe, but i heard if I run the OBDII headers with plugged EGR it will clear. Will the stock e36 cat pipe (that comes on the OBDI motor) directly bolt up to the OBDII manifolds? If not, what other mods will I need to make?

I need the stock exhaust components to pass CA B.A.R. :(

Or, can I just modify the cast ones easily?

[bimerok]

Is the E36 the same as the E34?

Close, but not the same. Not even all e36's are the same.

[2mAn]

Just ordered a new C101 plug along with new pins. Planning on cutting the X20 off my E34 harness and repinning into the C101 for plug and play fun. I have AKGs E30 to E36 wiring arrangement sheet. Is the E36 the same as the E34?

[bimerok]

Automatics do have flywheels, how else would the starter turn over the motor? It's just that you can't use auto flywheel for a manual trans.

Not so. Automatics do NOT have a flywheel. They have torque converters. Starter turning over engine using the "starter ring" with teeth or on some models teeth right on the torque converter.

If your idea of flywheel is to be there only for starter ring, you will need to brush up on basic engine how-to's and why's. :)

[cmeptb13]

I'm sure this is covered, but I've searched for a long time with no definitive answer. I have a m50nv that used to be an auto. Im swapping into a 318i with a zf320.
1)Does auto have a flywheel?
2)What is the preferred DD (some drift sessions too) flywheel and clutch set-up. Thanks

Automatics do have flywheels, how else would the starter turn over the motor? It's just that you can't use auto flywheel for a manual trans.

They do NOT, however, have pilot bearings. Which is a good thing because you don't have to pull it out. Just use the pilot bearing that's meant for the transmission you're using and pop it in there.

[drummerchubbs]

Thanks nokincy

[nokincy]

I'm sure this is covered, but I've searched for a long time with no definitive answer. I have a m50nv that used to be an auto. Im swapping into a 318i with a zf320.
1)Does auto have a flywheel?
2)What is the preferred DD (some drift sessions too) flywheel and clutch set-up. Thanks

1. No.
2. M20 or e36 m3

[drummerchubbs]

I'm sure this is covered, but I've searched for a long time with no definitive answer. I have a m50nv that used to be an auto. Im swapping into a 318i with a zf320.
1)Does auto have a flywheel?
2)What is the preferred DD (some drift sessions too) flywheel and clutch set-up. Thanks