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Old 03-14-2011, 02:22 PM
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#1 TDC = #8 TDC? (sbc)

I've set the valve lash using the 90* method on my solid cammed 383, but I've noticed that when #1 is @ TDC, #8 also seems to be @ TDC as there is lash present in both the rockers for #8. I know #8 follows #1 in the firing order, but alternative valve adjustment charts I've looked at show that only #8 exhaust should be on the base circle when #1 is @ TDC.

My cam duration is 249/249 @ 0.050.

Does this sound right?

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Old 03-14-2011, 02:40 PM
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Why don;t you use the correct tried and true method:: intake closes, set the ex, ex opens set the intake. Its just that easy. You'll only have to do it once.
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Old 03-14-2011, 10:44 PM
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Lots of ways to skin that cat. A Motors Manual will say you can set half the valves on TDC, rotate the crank once and set the other half. I always ended up with a couple noisy ones with that method.
On way to do it, and one I like for no particular reason, is to mark off the cylinders on the distributor, then set both valves on a cylinder when the rotor points to it's corresponding position.
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Old 03-14-2011, 11:23 PM
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When #1 is at tdc, #6 is also, but one of them is at the peak of the compression stroke and one is at the end of the exhaust stroke.

Contrary to most good advice, whenever I've set my lifters (hydraulics, not solids), I've found the best way to do it is to:
1. Use roller rockers with polylocks --- boy, does that make things easier.
2. Simply set the rockers fingertight to zero lash all around.
3. Bump the starter just a bit so that you see rocker movement (be sure the ignition is disconnected!) indicating that the open valve(s) has closed and another (or others) has opened.
4. Fingertighten them all again.
5. Repeat this process about a dozen times, more if you are the very cautious sort.

Chances are by this time you've gotten them all zeroed on the base circle of their respective lobes. I continue until I've gone about 4 or 5 starter bumps without finding any rocker that I can tighten further. It doesn't take very long. Now preload them with that extra 3/4 turn. And finally --- this is another reason roller rockers are cool --- start the motor and check to see if anybody is clattering around. Roller rockers don't squirt oil at you. You'll know fast one way or the other. Assuming the answer is 'no', put back your valve covers and go.

Last edited by Leoman; 03-14-2011 at 11:35 PM.
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