In Reply to: and probably the weight is further forwardtoo(6cyl posted by Darren on January 09, 2002 at 18:45:24:
No, I have not done it, but after receiving the bill for my S14 rebuilt, I had a second thought. But I have made some investigations.
To make the job possible, the engine management needs to be OBD1 (up to 1995). So, you need a complete 1995 M3 engine, tranny and harness (around $4K) or get a newer engine and buy the intake and the harness/DME from a 1995.
A few peoples do the conversion: Zionsville sells a comprehensive CD for Do-It-Yourselfers at $150, or Chris Wolford from Texas or Mike Robinson from Virginia can swap it for you. Or buy the CD or Robinson's instructions and do it yourself or by some mechanic you trust.
The S52 is 40 lbs heavier than an S14 but if you lighten the front end by removing AC or by installing a carbon hood, that weight imbalance is solved. But unless you track the car, I doubt you will feel the weight difference. And even on a track, you will have more torque and power. And because the S52 is nothing more than an stroked M52, it is a production engine that costs less to maintain.
Actually the S50/S52 is approx. 100lbs heavier than the S14. We determined this from multiple sources. Using 1kg=2.205lbs.
S14 110kg - 242.55lbs
S50 155,4 - 342.66lbs