3/4in NPT To 1.75in Hose

The 3/4in NPT to 1.75in hose fitting by CSR Performance is a precision adapter engineered for coolant system modifications, water pump upgrades, and custom cooling line routing in automotive engine builds. Mechanics and performance enthusiasts rely on this fitting to bridge incompatible connection sizes when fabricating custom water pump installations, radiator bypasses, or high-flow cooling circuits. Whether you're rebuilding a vintage engine with modern cooling components or designing a complete custom water management system, this aluminum adapter provides the reliable transition point your project demands.

Constructed from lightweight aluminum and finished with clear anodize protection, the 3/4in NPT to 1.75in hose fitting resists corrosion while maintaining compatibility with standard coolant chemistry and high-temperature operating environments. The 3/4-inch NPT male thread provides a sealed, vibration-resistant connection to pump ports or manifold outlets, while the 1.75-inch hose barb accommodates standard automotive coolant hose with positive mechanical grip and minimal leak risk. At 5 inches in length, the fitting offers adequate clearance for installation in tight engine bay configurations without requiring additional adapters or spacers, and the compact 0.42 lb weight contributes negligibly to overall system load.

This fitting excels in street rod restorations, LS engine swaps, and custom cooling system builds where original water pump inlet sizes don't match modern radiator hose standards. Installation is straightforward: apply thread sealant or PTFE tape to the NPT male thread, torque into the pump or manifold port, and secure your 1.75-inch hose with a worm-drive or band clamp to the barb outlet. For optimal reliability, use premium coolant hose rated for your engine's peak operating temperature and pressure—typically 16 PSI minimum for street applications. Verify pump thread compatibility before ordering, as NPT fittings require accurate port sizing for watertight seals.