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VALVE ADJUSTMENT
<--StartFragment--> Posted by Dave Dodge on April 14, 1998 at 21:28:13:
In Reply to: The valve thing... posted by DJ on April 14, 1998 at 11:35:28:
Over the years I have developed a method of adjusting the valves on V-4's that
is accurate and quick. The crank and rotor position is the same using the rotor
TDC marks. Make sure that the cylinder you are adjusting the valves for is on
TDC compression stroke. On the rear cylinders the cam lobes will be pointing
AWAY from each other, and on the front cylinders the lobes will be facing UP and
slightly towards each other when the particular cylinder to be adjusted is at
the correct position.
**IMPORTANT** Note revised measurements below.
Loosen and back off the adjusting nuts on the intake and exhaust rockers. Place
a .004" feeler gauge between the cam lobe and rocker arm. Snug down the
adjusting screws (with your fingers) until each screw just touches the valve tip,
then move the feeler gauge back and forth to make sure there is drag (not tight/not
loose) and tighten the nuts with a wrench. Now recheck the clearance
at the valve with a .006" feeler gauge. The feel should be a snug
.006" or a loose .005". Re-adjust the screw if you don’t get this
feel on all four valves. Use same procedure on remaining three cylinders.
There is a 1.5 to 1 rocker arm ratio, so .004" at the cam gives you a snug
.006" at the valve. This procedure reduces the risk of uneven rocker
adjustment. Once you get the feel of a snug .006" clearance, you will find
you have proper setting for long cam life and minimal (if any) clatter.
IMPORTANT: I always torque the adjusting nuts to 15 ft.lbs. Tighten the nuts
with a wrench enough so they wont come loose, then rotate engine until rocker
arm depresses valve about half way. This will allow room for the torque wrench
and the pressure against the adjusting screw will keep it from turning while you
are torqueing.
Ron Butterfield
***REVISED MEASUREMENTS***
DRP has tightened the tolerances by .001" since the procedure was placed on
the net. You now want .003" between the lobe and the rocker, which equates
to .005 at the valve tips. In the end you want no less than .004 (tight) and no
more than .006 at the valve tips. He posted this to the list on 10-7-99.
-update contributed by LAWRENCE ZOIA
<phezanthawk@email.msn.com>
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Bob
San Diego, CA
1985 V45 Sabre
rhampto1@san.rr.com <mailto:rhampto1@san.rr.com>
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