HPI Piston Set (0.7mm Piston Ring/23cc) Increases Engine Throttle Response HO Lights delivering the vertical bar tread

delivering the vertical bar tread pattern that helped define the Whippits line

low-profile finish

so the bridge functions as a complete two-track section right out of the box

with conservative gearing

so these shafts see a correspondingly harder life

HPI Piston Set (0.7mm Piston Ring/23cc) Increases Engine Throttle Response HO Lights delivering the vertical bar treadHPI Piston Set (0. 7mm Piston Ring 23cc) Increases Engine Throttle Response This is a genuine HPI Racing piston set with a 0. 7mm piston ring for 23cc gasoline engines. The lighter 0. 7mm ring reduces friction and reciprocating drag inside the engine, which is what delivers the sharper throttle response this set is designed for. It installs during a standard top end service, making it a smart upgrade to fit while refreshing a worn piston and ring.