JAKE

If you go that route, a bigger cam - longer duration - may well result in the cam having too much duration for the application. Increasing duration in order to get the desired valve lift isn't the way to go about it. The downside out-weighs the benefits. The downside being the need to increase the cam's duration in order to get the higher valve lift.

Has to do with the dynamic relationship between the lobe lift and the duration. High valve lift, while maintaining short duration, makes the ramps VERY steep/aggressive and at some point the valve train becomes unstable.

Camshaft engineers test these interactions/relationships and have determined how far they can push it and still maintain reasonable valve train stability and durability.

In an interview with a few cam company engineers, posted in one of the mags, one of them stated it's best to get your valve lift with a rocker ratio change.

Jake

tehcarguy

It really depends on how your motor is built. However, on a stock motor 1.6 rockers will result in a gain.

dogfish246

A cam increases the time that the valves are open (how long) while the RRs increase how much the valves open (distance)...

Rob31

What was meant was a cam that provided the same lift as the 1.6

C409

I converted a '74 C3 to a '93 LT1 / 700R4 and left the motor stock ... the only performance mod was a set of LT headers ... looking for cheap easy mods I decided to try the 1.6 rockers and picked up 0.14 seconds at an eighth mile strip and around 0.26 on a quarter miler