>When you are tuning the car, what torque do you use on the valves? I have
>a >slight racing cam in this car. One guy told me it is no big deal,
>another told >me if engine is not stone cold, the settings would not be
>right and are very
>critical, to prevent the cam from wearing out. Which is right?
A torque wrench is not necessary, and probably not POSSIBLE to use for this
application. I've never used one. The critical specification here is a
matter of CLEARANCE between the end of the valve stem and the end of the
rocker arm. There are a couple of different ways to go about this, but the
easiest for ME to remember is to start with the timing mark lined up so
that #1 piston is at TDC on the compression stroke. (Double check this by
popping the distributor cap and making sure the rotor is pointing at the #1
terminal... also, the rockers for #1 will have a little slop in them)
Then, you loosen the securing nuts on the ends of the rockers... just
loosen!! All you want to do is to be able to rotate the set screw within
the nut. With the nut tight, the set screw will not rotate. Put a box end
wrench around the nut (just let it hang out there!) and use a screwdriver
for the set screw. Anyway, you use a feeler gauge of the appropriate spec
and slide it inbetween the rocker and the valve stem. While sliding the
feeler gauge back and forth, tighten the set screw until you feel a "slight
drag" on the feeler. This is the tricky part, 'cuz it's tough to know what
exactly "slight drag" means. What I like to do is once I think I'm close I
try to ROCK the feeler slightly and see if I feel it rocking... if I do,
then it should be JUST A BIT tighter. When you're satisfied with the
clearance, and with the screwdriver still in place, hold the driver firmly
while tightening the nut. Trick here is to not let the screw rotate
anymore, 'cuz then you've changed the clearance again. You do both the #1
rockers this way, and then turn the engine over to the next cylinder in the
firing order. (1-5-3-6-2-4) You can tell when you're at #5 when the rotor
points right at the #5 terminal and #5's rockers are loose. Do this for
each cylinder. I like to take the plugs out, too, 'cuz it makes turning
the motor over easier. (don't use the starter.) As far as torque goes,
all that nut has to do is keep that set screw from moving. Go easy on it.
If one ends up backing off a little, well that's no big deal. Worst case,
you'll have to adjust the valves again, and it really isn't all that hard!
Others will tell you other tricky sequences which you might find easier.
You'll just have to write them down... my sequence is easy as long as I can
remember the firing order. Point is, aside from speed, there is no reason
to use one sequence over the other. Someone correct me if I'm wrong.
The next trick is to know what your clearance should be. Different cam
grinds have different specs. Stock is .010", while mine is .014". You
really have to know what that spec is. The other thing is that you should
do the work after running the engine to operating temp. I've done this
operation in about an hour before, which I was proud of, but I bet there
are others reading this that can do it much faster! Obviously, speed is
not your concern though!
Hope this helps!