B58 Billet Main Caps by 5150 AutoSport Block Rings ensuring exceptional strength and thermal

ensuring exceptional strength and thermal stability under high engine loads

Prevent Valve Float for Maximum RPM Control

Model Years equipped with this motor vary by region

Fits BMW E36 and E34 with M5X motors

Turbo or supercharged setups

B58 Billet Main Caps by 5150 AutoSport Block Rings ensuring exceptional strength and thermal5150 AutoSport B58 Billet Main Caps As power levels climb beyond 1,200+ horsepower, we've seen factory main caps begin to walk. Under extreme cylinder pressure and crankshaft loads, even the slightest cap movement can affect main bearing alignment, oil clearance, and ultimately bearing life. Our CNC machined billet steel main caps are heat treated for maximum strength and feature a dowel pinned design to positively locate each cap and virtually