dods1600

I've heard duration is what can give rough idle the longer it is because of valve overlap, but what would be the major differences in results between a 0.410 and a 0.473 lift?

1600cc biggest most powerful engine for a stock beetle. Power house!:) Smokes the tires in first in the rain
Quote 0 0
Ryan

More lift means the heads can flow more, well that is provided the ports can actually flow it.  You can't really look at lift without looking at duration too.  How fast the ramps on the cam are play a role in 'how' the engine makes power and that's a function of lift and duration.  Usually the two come together, meaning you get more lift and duration together.  Increasing both will help prevent severe ramp angles that can cause valve control problems and/or wear parts out faster.  However lazy ramps, say low lift / high duration will make less power and you'll have to rev the engine more to get it.  It's really just a fine balancing act.  Talk to your cam grinder and head porter and they will help you make the decision of what cam for what type of head setup.  --Ryan

Quote 0 0
dods1600

Thanks a bunch Ryan that certainly does help me.

1600cc biggest most powerful engine for a stock beetle. Power house!:) Smokes the tires in first in the rain
Quote 0 0