IE Billet 4140 Tall Boy Main Caps (VW 4 CYL)

The tall boy VW 4 cylinder main caps are carefully crafted, in-house, from USA 4140 alloy steel. They provide extreme rigidity to the main bearing and crankshaft, and a flat foundation for a bedplate or crankshaft girdle installation.

These main caps are special because they are designed to work with a crankcase bedplate / girdle. Typically, the installation of those products requires machining small spacers, which go between the main cap and the girdle, bringing it up to the same level as the pan rails. What we found is that these spacers are very difficult to machine to the correct height. Even when done with extreme care, this compromises the installation and results in a warped girdle. Our solution to this is these Tall Boy Main Caps. These stand slightly proud of the pan rail as they come out of the box. They are then machined level with the pan rail, resulting in a perfectly flat surface for the installation of your bedplate / girdle, and the most rigid foundation for your crankshaft possible. In addition, the large profile and high strength material is much stronger and stiffer than the factory main caps.

If you are not using a girdle, please purchase our standard VW 4 Cylinder billet main caps.

Requires machine work including line bore & hone for fitment.