O.S. Engine OS45526400 M12 Exhaust Header Pipe Nut for FS120SII FT120 FT160 FF320  [OS45526400]

Exhaust Header Nut Overview

This M12 exhaust header pipe nut is an OEM-fit accessory intended for RC-scale nitro engines. It serves as the threaded fastener that secures the exhaust header to the engine flange and the tuned pipe, keeping the manifold sealed and aligned under vibration and heat cycles typical of model use.

Compatibility is limited to the model codes listed in the product title; confirm your engine model before installation. The nut's role is primarily mechanical: it clamps the header flange and ensures the exhaust pipe maintains its designed position, which affects backpressure and throttle response in fine-tuning scenarios.

Installation notes: hand-start threads to avoid cross-threading, then torque gently with the appropriate wrench to seat the nut without over-stressing the flange. Periodic inspection is recommended after break-in and after aggressive running, as heat and vibration can loosen small fasteners on nitro engines.

Practical tuning tip: when adjusting pipe length or changing a tuned pipe, loosen the header nut just enough to reposition the pipe, check alignment, then retorque to maintain a consistent seal and repeatable performance results.