The internal assembly of your HPFP is a delicate balance of astonishingly high pressure and extremely delicate tolerances. Every piston and cylinder is a match set CNC machined to exacting sizes. Tolerances between the two are hand-tested using precise measurement gauge tools and verified down to 0.46055"! These tolerances are required due to the maximized size of our pump assembly and absolutely critical for HPFP reliability and function. Even the smallest contamination can cause pump wear or failure, to ensure this each pump is assembled in a clean environment with a Laminar flow hood. This is why IE only sells HPFP pumps fully assembled in new OE housings as to ensure reliability.
Verified critical tolerances
Ready to install complete pump
Clean environment assembled