REPAIR OF THE BED OF THE CRANKSHAFT AFTER TURNING THE LINERS IN THE BLOCK BMW N57
🛠️ CAUSES OF DAMAGE AND WEAR OF CRANKSHAFT BEDS:
✔️ Changing the shape of the crankshaft beds. Increase or decrease the size of the beds. It often appears in an elliptical shape. It can be caused by prolonged and intensive operation of the engine under various loads and insufficient lubrication of the main bearings.
✔️ Rotate the insert. Occurs due to high temperatures in the friction zone of the bearing and neck. This leads to the melting of the antifriction layer, the "sticking" of the liner and the formation of a deep working. Basically, only one of the supports is damaged.
✔️ Bed misalignment.
✔️ Breakage of covers of crankshaft beds (yokes). Such a KShM element most often undergoes cracking (destruction), since it takes on the greatest loads.
✔️ Deformation of yokes with loss of tightness during installation.
🛠️ STAGES OF CRANKSHAFT BED RECOVERY:
✔️ Pre-boring (preparation for welding)
✔️ Welding work
✔️ Milling of contact planes of yokes of damaged crankshaft beds
✔️ Milling the groove for the lock of the liner
✔️ Installation of yokes
✔️ Boring crankshaft beds
✔️ Finished result