BMW S55 Pinned Crank Hub & Timing Chain Replacement Pt.3 (2015-2021 BMW F80 M3, F82/83 M4, F87 M2)

BMW's S55 engine was a blessing for M fans worldwide. Although it meant the end for its predecessors' high-revving, naturally-aspirated engines, the turbocharged straight-six is an ultra-reliable, overbuilt powerhouse that produces a fat power band in stock form. However, pushing beyond factory output stresses the timing chain drive system. If you want to take advantage of the S55's ability to make significant power, you should look into installing a modified crankshaft hub.

As if reaching the crank hub and replacing it weren't challenging enough, there are a few really important steps while putting everything back together. Without a doubt, the most important is timing the engine, ensuring the valve and pistons don't make contact at any point. Then you just have to refit everything in the front of, around, and on top of the engine. Oh, and don't forget to torque everything to the proper spec!

In part three of this three-part DIY, FCP Euro's BMW Expert, Gareth Foley, reassembles the BMW F82 M4 after installing the pinned crank hub.