View Single Post
911st 911st is offline
Registered User
Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
Got it.

I am just starting to learn about cams.

I played with some numbers for our cams, ports, and the curtain area under the intake valve seat.

It seems that our valves only have to be open about 40-50% to equal the same area as our ports. Even on something like an SC or 3.2 w larger ports.

This fits with what your guy was saying.

If so, extra lift is not what gets us more into the cylinder!

I suspect total lift on our cars is more a product of duration. That is if the valve is going to be open longer, we need a larger dome on the lobe to accommodate it.

The byproduct of this might be that the valve dose open quicker with more lift (steeper ramp) and that to might help increase total flow potential to a small degree.

Just guesses and I would like to know if I am on the right track.

Many say the SC cam makes more low end than a C2. I am thinking that is because the C2 has more lift and can not be advanced as far without increasing piston interference potential.

If one wanted to retard an SC cam instead to early 3.0 specs it should move the HP peak from the 5500 we see on a 930 to about 6000rpm which should put it on par with the C2 cam.

Just a guess.
Old 01-28-2010, 02:48 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)