why do people use S50 valve covers on S52 motors?

[CosmoE36]

i found cars that ar 95 with obd2 S52 motors in them but they all have S50 covers on them and the owners tell me that its the "proper" way to do the conversion. so now instead of just looking at the valve cover i have to either take the owners word for it that it is a 3.2 motor or crawl up under the car and look for some type of mark which i hate doing lol.

anyways my main quesiton si why is it the PROPER way of doing the 3.2 swap into a obd1 car...

sorry for sounding like a newb

[BCM M3]

I believe it is because the 3.2 is converted to OBD1 using some of the original S50 parts, and the valve cover is one of them.

[CosmoE36]

hmm but they still retain the S52 block and head correct?

[Ali]

You can do it both ways, My brother put a 3.2 obd1 in his car and retained the obd2 valve cover. On my car I have a 3.2 obd1 but I have the obd1 valve cover (although I have an m3 lightweight head)

[CosmoE36]

what are the markings on the motor to determin if it is a real S52 and not a S50? is there a block code that says S52 stamped somewhere?

[Serious]

build date are stamped on the block.

[Serious]

mine has s52 cover

[funkmasta]

In front of the starter there will be a crank sensor in the 3.2 motors. Also you can look for spliced wiring, although it will take a trained eye to decipher which is stock, which isnt.

[GGray]

Yup he's right it has an extra crank sensor hole...I used the OBD 1 cover it was much easier than mangling adapting the OBD2 cover. ANd I drilled the block so my car is 100% factory. If I have to ever put a 3.0 back in it will bolt right back in...