P2R Lost Motion Assemblies (LMAs) will replace the factory Piston style LMA found on the 01-03 J series like the J32A2. They will also fit the 04+ J series. The LMA is designed to pre-load the VTEC rocker when the VTEC is off.¬†The P2R LMAs¬†are designed and produced to¬†the highest quality standards using hardened tips and have been WPC friction treated to give extra wear resistance. Sold as a set of 6. These have been tested and proven to work in P2R’s race cars over the last several years.
To understand a little more about what this does you need a little understanding of how VTEC works. Basically, normally an engine uses multiple cam profiles for a given set of cylinder valves. So on a 4 valve head with a single overhead cam configuration, there is a set of cam lobes for the intake side and a set for the exhaust side. VTEC incorporates a second set of lobes on the intake side which have a different profile for a higher performance level. All these lobes have their own rockers, and the engine “switches” the cam profile by locking the rockers together (using oil pressure).
As you can imagine, when the “low” rockers are on, the high rocker is just freewheeling against the cam not doing any work. Once the rockers are locked together, the “high” cam lobe actuates the “low” rockers. This usually happens at mid-range RPM and is computer-controlled.
When the RPMs drop back down, VTEC disengages the high cam rocker from the low rockers, and you are in “low mode” again. This action can cause some “flopping” or free play in the high-cam rockers.
The Lost Motion Assemblies dampen and preload the “high” cam rocker because unlike the low rockers, it does not have a valve to counteract its movement when cam actuates it. It’s an important part of making sure the VTEC action is smooth, noise-free, and seamless.
In aggressive driving or with more performance cams installed, the need for the LMA to do its job well is even more important. Aftermarket performance applications benefit from aftermarket performance LMAs!
Thanks to P2R for releasing this solution!