ScienceofSpeed Billet Main Cap Set - NSX, 1991-05

For high horsepower applications or race use, ScienceofSpeed offers main caps manufactured from billets of high strength carbon steel.

The factory main caps are manufactured from grey cast iron with an approximate tensile strength of 30,000 PSI. The cast iron has inherent porosity and failure by fracturing through the oiling hole have been observed in high performance applications.

ScienceofSpeed offers a direct replacement main cap set machined from billets of carbon steel. The caps, when machined, are oriented with the dense granular structure spanning the length of the cap for maximum strength. The set of four main caps are heat treated and engraved with orientation position in the cylinder block.

Main bore is left .025" undersized. Block and caps must be align bored & honed to final finished size. We recommend use of the ARP Main Stud kit, which should be installed when the main bore is machined & honed.