User Guide

Dyno2000 Advanced Engine Simulation—65
Camshaft Modeling
should be interpreted to fall within a range of dimensions that are commonly asso-
ciated with applications requiring optimum power at peak engine speeds.
CAMSHAFT MENU
The final component category allows the selection of the single most important
part in the IC engine: the camshaft. For many enthusiasts and even professional
engine builders, the subtleties of cam timing defy explanation. The reason for this
confusion is understandable. The camshaft is the “brains” of the IC engine, directing
the beginning and ending of all four engine cycles. Even with a good understanding
of all engine systems, the interrelatedness of the physics within the IC engine can
make the results of cam timing changes read like a mystery story. In many cases
there are only two ways to determine the outcome of a modification: 1) run a real
dyno test or 2) run a simulation. Since the camshaft directly affects several functions
at once, e.g., exhaust and intake scavenging, induction signal, flow efficiency, cyl-
inder pressures, etc., using a computer-based engine simulation program is often
the only way to accurately predict the outcome.
The Dyno2000 makes it possible to test the effects of cam timing in seconds. The
Valve Motion Diagram
.000
020
40 40
60100140 180 220260300 60 100 140 180 220 260 30020
.050
.100
.150
.200
.250
.300
.350
.400
.450
.500
60° ABDC24° ATDC24° BTDC60° BBDC
INTAKE EXHAUST
BDC
TDC
BDC
IVO IVCEVO EVC
ICAECA
VALVE MOTION CURVES
Exhaust
Centerline
Intake
Centerline
The best way to visualize
camshaft timing is to use
this “twin-hump” event
drawing. It shows valve
motion for the exhaust
lobe on the left and the
intake lobe on the right,
positioning the valve
overlap and TDC at the
center. Study this
picture. It will help you
quickly evaluate cam
timing specs and visual-
ize how they relate to
one another.
Camshaft Menu
The Dyno2000 can test the
effects of cam timing changes
in seconds. Several cam pro-
files are included in the drop-
down menu, and you can easily
input any custom timing and
valve lift specs. Test cams from
manufacturer catalogs or load
camfiles directly from the
Motion Software CamDisk™
containing over 1200 read-to-
test cams.