Timing chain

[Kdubski]

Assembling top half of motor following a full rebuild. All of my parts were washed and markings came off (sprockets, chain, vanos hubs). I'm following TIS for all procedures, but are there any guides on assembling the timing system from scratch? Also, how do you ensure the timing chain is seated correctly between the 2 sprockets (i.e. installed on the right tooth)?

Thanks

[heinzboehmer]

First, make sure the engine is at TDC. There's a mark on the harmonic balancer and the cam lobes for cylinder 1 will be facing each other. Then you can just slip the chain and sprockets onto the intake and exhaust cams. The "right tooth" is wherever the chain lands. Both cams have variable valve timing, so the VANOS is what couples the chains to the cams.

After the chain is in position, reassemble all the VANOS stuff and time the engine correctly. Read through both of these links, they should give you a good idea about how the system fits together.

https://m3support.net/thread/186/e46-m3-cams-diy

http://www.beisansystems.com/procedures/s54_vanos_procedure.htm

The most important part of all this is the timing. Follow Beisan's procedure exactly as described. Also make sure to get the genuine BMW timing bridge. Aftermarket ones have poorer tolerances and can lead to a mistimed engine and bent valves.

[DanAvoN7]

The TIS or Beisan Systems "S54 Vanos Rattle Procedure" (which is the same procedure as the TIS but with color pictures) are the correct way to do the job. Read through the TIS a few times and follow it exactly. The TIS link below is what you want to follow

https://www.newtis.info/tisv2/a/en/e...mshaft/4PH6wZa


There are far too many vanos DIY guides, DIY videos, etc. that include useless steps, are flat out wrong and risk damaging your engine due to incorrect engine timing, etc. There is no need to "mark" anything prior to disassembly and you should be assembling it from scratch so that you ensure the engine is timed correctly. What happens if you "marked" something prior to disassembly that was taken apart by the previous owner and then installed in the wrong position? Use a Genuine OE BMW timing bridge with 1 pin and follow the TIS or Beisan Systems procedure and you will be fine.

[Arith2]

The most important part of all this is the timing. Follow Beisan's procedure exactly as described. Also make sure to get the genuine BMW timing bridge. Aftermarket ones have poorer tolerances and can lead to a mistimed engine and bent valves.

+1 with special emphasis on not getting an aftermarket bridge. I had one of those that was out of tolerance.

[mrgizmo04]

+1 on not worrying about previous markings, just stick with the procedures step by step.