S63 Rod Bearing Journal Widening Kit Including Crankshaft Journal Modification
Unfortunately the S63 and N63 engines are suffering frequent rod bearing failure. Unlike previous engines like the S65/S85 this engine platform was designed with industry standard rod bearing clearance. The overall rod bearing surface area on this engine is small from the factory, and with turbochargers even a stage 1 tune with stock turbos seems to stress the rod bearing beyond it's capability. Our solution to this is pretty simple and a tried and true method we have used on many other engines. We take the stock crankshaft and widen the rod journal on it and increase the surface area of the bearing by 15%. We chose a rod bearing that was a significantly wider than the S63 stock bearing but also slightly smaller in diameter. This allows us to take damaged crank journals and have them re-ground to accept our wider bearing. Once the crankshaft is modified we then heat treat, plasma nitride, and dynamically balance it.
This modification has many benefits, both in engine reliability and in economics. Most obviously the wider rod bearing will increase rod bearing/rod journal surface area. This change between the bearing and journal provides increased protection against crankshaft journal to rod bearing contact and prolong the overall life of the rod bearing. This also allows the bearing to handle more potential torque from the piston, a good idea if you are considering larger turbochargers, or racing. The remaining benefits have a lot to do with the economics of rebuilding an S63 engine. The cost of OEM BMW parts have always been high, but we chose rod bearings and rods that don't have a long lead time to manufacture and in most cases we will have all these items in stock.
This package is sold as a combination of crankshaft, rod, and rod bearing. The rod we choose is a very important part of our package. We believe if you can't use a part that's better than OEM then it shouldn't be used. Our rods are manufactured by Carrillo rods here in Irvine California using high quality forgings. We've designed our kit to utilize the OEM rod length compensating for the change in rod bearing. This means that the end user has many "off the shelf" options when it comes to piston choice. If your engine has good pistons you are able to reuse those, or purchase new pistons, or purchase new aftermarket pistons from any manufacturer. This kit does require that you provide a core S63 crankshaft, one with spun rod bearings is typically acceptable, there is an extra 200 dollar charge if the mains need to be ground. We use a commonly available Mahle Clevite bearing in this kit.
For an additional charge we also do complete bottom end or complete long block assembly in house and international shipping is available.