Can anyone explain why high lift and long duration cams such as (toda b & c) causes piston to valve clearance issues in a ls/vtec with stock bottom end. Also what can be done to prevent this problem for happening. Thanks in advance.

 

in theory, because it opens the valve more with its higher lift, and keeps it open longer due to duration. So, if you take engine a with stock cams, and engine b with say toda c's... the valves are open longer on engine b. However, the one thing that doesn't change is the stroke, so the piston is in the same spot on both engines at any given point. (theoretically) Thats my poor attempt at explaining it. *shrugs*

 

oh, and BTW.. might want to move this to the Tech. section of HT.