View Single Post
Old 05-25-2011, 11:17 PM   #34 (permalink)
Dean in Milwaukee
EcoModding Lurker
Join Date: Jan 2010
Location: milwaukee
Posts: 34
Thanks: 0
Thanked 5 Times in 4 Posts
Higher compression adds mechanical advantage to the power stroke, independant of other also desirable factors.
Consider that an engines effective power stroke is mostly done barely 1/3 way down the stroke, and think about it this way:

Imagine a small firecracker being used to push a cannon ball out of a cannon. Would you get the best push on the cannon ball if the ball was right down on tight on top of the firecracker, ( high compression)or if it was held a bit away, giving some volume around the firecracker? ( lower compression)

Having a fixed and limited amount of firecracker produced gas available means that with more chamber volume the peak pressure realized will be reduced, reducing energy transfered to the cannonball even though you used the exact same firecracker, and the cannonball will go less far.

Hope this helped.

Dean in Milwaukee
  Reply With Quote