Re: Camshaft tech

From: Sean_Meldrum@ittauto.com
Date: Wed May 20 1998 - 12:21:32 EDT


It seems the data at the end of my previous post was a little messed up.
Here's the corrected info....hopefully it formats ok:

Camshaft Tech:

                           Varying Lobe Separation Angle
+--------------------------------------------------------------------------
----------------------------------------------+
| Tighten |
                   Widen |
|-------------------------------------------------------------|------------
--------------------------------------------------|
| Moves Torque peak to lower rpm | Moves Torque peak to higher RPM
     |
| Increases Maximum torque | Decreases Maximum Torque
                |
| Narrows Powerband | Widens Powerband
                              |
| Builds higher cylinder pressure | Reduces maximum cylinder
pressure |
| Increases chance of knock | Decreases chance of knock
                |
| Increases cranking compression | Decreases cranking compression
        |
| Increases effective compression | Decreases effective
compression |
| Idle vacuum reduced | Idle vacuum increased
                        |
| Idle quality reduced | Idle quality improved
                            |
| Open valve-overlap increases | Open valve-overlap decreases
           |
| Closed valve-overlap increases | Closed valve-overlap
decreases |
| Natural EGR effect increases | Natural EGR effect reduced
               |
| Decreases Piston-10-valve clearance | Increases Piston-10-valve
clearance |
+--------------------------------------------------------------------------
-----------------------------------------------+

         Lobe separation Angle
+--------------------------------------------------------------+
| Above 114 degrees = Extremely wide |
| 114 - 112 degrees = Wide |
| 112 - 110 degrees = Moderately wide |
| 110 - 108 degrees = Moderate |
| 108 - 106 degrees = Moderately tight |
| 106 - 104 degrees = Tight |
| Below 104 degrees = Extremely tight |
+---------------------------------------------------------------+

                            Advancing/Retarding Cam Timing
+--------------------------------------------------------------------------
----------------------------------------------------------+
| Advancing |
                        Retarding |
|-----------------------------------------------------------------|--------
------------------------------------------------------------|
| Begins intake event sooner | Delays intake event
sooner |
| Open intake valve sooner | Keeps intake valve
open later |
| Builds more low-end torque | Builds more high-end
torque |
| Decrease piston-intake valve clearance | Increase piston-intake valve
clearance |
| Increase piston-exhaust valve clearance | Decrease piston-exhaust valve
clearance |
+--------------------------------------------------------------------------
------------------------------------------------------------+

*** 97 RPM Dakota - 14.98 @ 91.76 *** http://surf.to/real-per4mance ***

sean meldrum
Email @ Home: spm@c3net.net
Email @ Work: sean_meldrum@ittauto.com
Truck mods: http://www.geocities.com/MotorCity Downs/7875/signature.txt



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