tonymcilroy

I am considering these 1.6 rockers on my zz4 motor. Anyone tried this? Performance gains? Any problems?

cv67

5-10hp if youre lucky
may need to check for coil bind, retainer to guide clearance
increasing ratio willmake the springs work harder

sure wont hurt ya just dont expect much.

techinspector1

I have never been a fan of increasing the rocker arm ratio over stock. As alluded to by the previous poster, this increases the effort required of the entire system as well as reducing piston to valve clearance, perhaps to the point of interference, and introduces the possibility of valve spring coil bind or retainer to seal interference. When the motor was designed at the factory, very highly paid and highly trained professional engineers designed the whole mess to work together in concert toward a common goal. While some of these things can be changed, replacing longevity with increased performance over the short haul, changing rocker arm ratio would not be something I would be interested in doing. There are far better methods of increasing power in my opinion.