Dual ratchet design. Tighter tolerances than OEM Honda chain tensioner. More durable than OEM unit. A must have if your using aftermarket cams and valve springs. Description Vehicle Fitment Technical Data Included Install Guide Despite being a fairly robust motor, k series engines have been found to have weak timing chain tensioners that fall victim to excessive wear when aftermarket cams are installed in the motor (and in some instances with stock cams). The fast ramp rate of aftermarket cams is the main cause of this. Unfortunately, without tearing the motor down after every use, it's almost impossible to detect a worn tensioner before it's too late. While installing a stiffer spring in an OEM tensioner, like other companies do, will slow down the wear of an OEM style tensioner, it will not eliminate it. The use of a stiffer spring will also cause the timing chain to stretch faster. For this reason, we designed our chain tensioner from scratch, ensuring it could take the abuse aftermarket cams without causing faster than normal stretching of the chain. The Hybrid Racing Chain Tensioner is designed to be both stronger and more durable than the OEM Honda chain tensioner found on K Series motors. It is perfect for anyone who wants some added protection for their valuable motor. The tensioner functions exactly like the OEM unit it replaces while improving upon the flaws of Honda's design. The dual-ratchet design features hardened tool steel teeth that mesh with a heat treated chromoly piston. The teeth are crafted from the same material used for most the ratchets in high-end impact wrenches. The piston is designed to fit into the K series engine's timing chain guide tighter than the OEM unit does; this helps to avoid misalignment of the ratcheting mechanism and the premature wear that often occurs when aftermarket cams are used in conjunction with the OEM K Series chain tensioner. In addition, the internal oil passageways have been optimized to respond to oil pressure increase faster than the OEM unit; this becomes critical in motors that rev quickly and to high rpms. Each Hybrid Racing K Series Chain Tensioner is manufactured from scratch. It is not a rebuilt and rebranded OEM tensioner like those sold by other companies. The Hybrid Racing chain tensioner comes with reliability that has been proven through years of the most abusive testing and refinement. Fits: 2002-2006 Acura RSX 2004-2008 Acura TSX 2006-2011 Honda Civic Si All K-Swaps using one of these engines or similar K-Series engines