View Single Post
Old 05-26-2013, 06:45 PM   #8 (permalink)
Shortie771
Eco Sol
 
Shortie771's Avatar
 
Join Date: May 2009
Location: Paradise, TX
Posts: 343
Thanks: 24
Thanked 88 Times in 52 Posts
Quote:
Originally Posted by smokey442 View Post
What you gain with both the miller or Atkinson cycle is an increase in the expansion ratio. Most engines specify compression ratio. Mathematically compression and expansion ratio are the same. You can manipulate them mechanically in them in the case of the miller cycle by delayed intake valve closing. This lowers the pre combustion pressure to lower the detonation threshold for a given octane. Small gain in reduced pumping losses at part throttle by reducing intake vacume. You do not need a supercharger to take advantage of this method.
Can this be done to the stock camshaft? I wonder how that conversation would go at a machine shop... Me: "I would like to get an Atkinson regrind on my cam." Machinist: "You want to, huh?"
__________________




Best Tank = 42.72 mpg (in the 94 Del Sol)

CR-Z Current Mods:
Max Sidewall PSI
  Reply With Quote