Installing
and adjusting (or "degreeing") the camshaft can
be tricky. It can be done using either:
•
The theoretical
centerline of the #1 intake lobe, or
•
The valve opening
and closing events, based on a
pre-determined amount of Lift (usually
0.050 in.).
The centerline method is not
always reliable with Asymmetrical Lobe Profiles.
For best accuracy, the following is a
combination of methods.
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What tools will I need?
•
Tools to assemble and
adjust the valvetrain
and timing set.
•
A
Cam Degree Kit
•
A
Crankshaft Socket (Some
crank sockets attach the
degree wheel to the
socket. This makes
adjustments much
easier.)
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Are there any tips
before I begin?
•
Before
installing the camshaft
and lifters, wash them
in mineral spirits to
remove the rust
prevention coating. Then
apply a generous coating
of Assembly/Break-In
Lube.
•
If the
opening and closing
points on the Cam Card
are listed at 0.050 in.
of lift at the cam AND
you are measuring lift
at the valve, be sure to
take Rocker Arm Ratio
into account.
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•
For
the sake of simplicity,
these instructions
assume you are measuring
lift at the valve.
•
Make
sure the values listed
on your cam card are
listed for the part of
the valvetrain you are
measuring.
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Initial Steps -
Installing Pieces and
Parts
1.
Install checking springs
on the #1 cylinder
valves.
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a.
If
using solid lifters,
place the dial indicator
directly on a solid
lifter.
2.
Install the camshaft and
timing set according to
manufacturer
instructions.
3.
Install the degree wheel
on the crankshaft.
4.
Attach the pointer to
the block.
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a.
Any
bolt hole should work
fine.
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b.
Make
sure the pointer is
aimed directly at the
center of the wheel.
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c.
Make
sure the pointer tip is
near the edge of the
wheel.
5.
Adjust the degree wheel
to Top Dead Center
(TDC):
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a.
Bring
the #1 piston close to
TDC on the Compression
Stroke (both valves
closed).
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b.
Without moving the
crank, adjust the degree
wheel so the pointer is
at TDC (or 0¡ã).
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c.
Turn
the crankshaft about 1/4
turn backwards to lower
the piston.
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d.
Install the piston stop
in the #1 spark plug
hole.
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e.
Slowly
turn the crankshaft
forward (normal
direction) until the
piston contacts the
piston stop.
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i.
Record
this reading on the
degree wheel.
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f.
Slowly
turn the crank backward
(opposite direction)
until the piston hits
the piston stop again.
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i.
Record
this reading on the
degree wheel.
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g.
If
piston is at TDC,
readings will be equal.
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h.
If
not, split the
difference and adjust
the degree wheel without
moving the crankshaft to
achieve equal readings.
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i.
Turn
the crank from stop to
stop again to confirm
TDC.
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i.
Readings should now be
equal.
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j.
Rotate
the crankshaft to lower
the piston.
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k.
Remove
the piston stop.
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l.
Rotate
the crank so #1 piston
is at TDC.
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i.
Both
valves should be fully
closed.
6.
Install a Solid Lifter
or Hydraulic Lifter in
the #1 intake lifter
bore.
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a.
Be
sure the type of lifter
(Flat Tapper or Roller)
matches your cam.
7.
Install the pushrod and
rocker arm on the intake
valve.
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a.
If
using hydraulic lifters,
be sure to use an
Adjustable Pushrod to
keep valvetrain
geormetry the same.
8.
Set
valve lash and preload,
as appropriate.
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a.
Solid
lifters: Set Valve Lash.
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b.
Hydraulic lifters: Set
Preload.
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Next Steps - Adjusting
and Degreeing the
Camshaft
9.
Set up
the dial indicator on
the valve retainer.
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a.
Make
sure the probe on the
dial indicator is
aligned with the
direction of movement.
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i.
This
will reduce any
geometric error in
measurements.
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b.
Make
sure the dial indicator
has enough travel to
account for the max lift
of your cam, plus 0.050
in.
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i.
This
will ensure the dial
indicator won't bottom
out and give a false
reading.
10.
Check
the intake centerline
(and adjust the camshaft
if needed):
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a.
Rotate
the crankshaft forward
until the dial
indicator's needle
stops.
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i.
You
have reached max lift.
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b.
Check
the probe to make sure
it's still resting on
the valve retainer and
has not bottomed out.
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c.
If
everything is OK, turn
the face of the dial so
the needle is pointing
at zero.
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d.
Turn
the crank until you
reach 0.050 in. before
max lift.
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i.
Record
the reading.
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e.
Continue turning the
crank until the needle
indicates 0.050 in.
after max lift.
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i.
Record
the reading.
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f.
Calculate the intake
centerline:
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i.
Add
the 2 readings together
and divide by 2.
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ii.
For
example, 150¡ã + 66¡ã =
216¡ã / 2 = 108¡ã.
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iii.
This
is the theoretical point
of maximum lift.
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g.
Compare the calculated
intake centerline to the
cam card.
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i.
If
you're within 1¡ã of the
listed value, continue
to Step 11.
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h.
If
more than 1¡ã off,
reposition the camshaft
by adjusting the timing
set according to the
manufacturer's
instructions.
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i.
If
your calculation is
smaller than what is
listed, the camshaft is
advanced.
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ii.
If
your calculation is
larger, the camshaft is
retarded.
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iii.
Follow
this link for more on
Advancing and Retarding
a Camshaft.
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i.
Perform the centerline
procedure again.
11.
Once
intake centerline is
correct, check the
opening and closing
points of the intake
valve at 0.050 in. of
lift:
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a.
Set up
the dial indicator as
before and turn the
crankshaft until the
valve closes.
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b.
The
needle will stop moving
when the lifter is on
the base circle on the
camshaft. At this point,
turn the dial face until
the needle points at
zero.
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c.
Turn
the crank slowly until
the needle reads 0.050
in. of lift (valve is
opening).
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i.
Record
the reading on the
degree wheel.
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ii.
Remember: If the valve
events are listed at
0.050 in. of lift at the
cam, multiply 0.050 in.
by your rocker ratio.
Then record your lift
points at that amount of
lift.
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iii.
For
example, on an engine
with 1.5 rockers: 0.050
in. of cam lift x 1.5
rocker ratio = 0.075 in.
of Valve Lift.
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d.
Continue rotating the
crankshaft past the
point of max lift until
the valve is 0.050 in.
from zero lift (valve is
closing).
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i.
Record
the reading on the
degree wheel.
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e.
Compare the opening and
closing points to the
cam card.
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i.
If
within 1¡ã, the camshaft
is installed correctly.
Continue to Step 12.
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f.
If
more than 1¡ã off,
reposition the camshaft
by adjusting the timing
set according to
manufacturer's
instructions.
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g.
Perform the above
procedure again.
12.
Once
the intake lobe is
positioned correctly,
follow Steps 10 and 11
for the exhaust valve.
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Final Steps - Finish
Installing Pieces and
Parts
Once the
exhaust valve is positioned
correctly:
13.
Remove the dial
indicator and degree
wheel.
14.
Remove the checking
springs, if used.
15.
Reinstall the proper
valve springs.
16.
Lubricate and install
the proper lifters,
pushrods, and rocker
arms.
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Contact Info
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NewCams
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