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Discussion Starter · #1 ·
Hello Guys,
Im new to the forum and have a question. I a going to do a valve adjustment on my stroked 350, it has a larger cam in it, not sure of the duration, but I cant help but think that there is a different process to adjusting the valves with a larger cam then the stock cam process. And what I mean is with a stock cam, you turn to TDC, and adjust a CYL 1 exhaust/intake, and then another series, then rotate 360, start on CYL 6 and so on. But with a bigger cam, wouldnt that process change? as if you would want to do each cylinder individually because the duration's are bigger and different? Any info would be great, or just let me know if Im off my rocker.

Thanks,
Mike
 

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with larger cams depending on grind, a cam can have more valve overlap meaning both valve are open at the same time as one closes and the other is opening, so weather its solid lifter or hydro lifter, its best to do the EOIC method.. Exhaust open Intake Closed.. When the exhaust valve starts to open,set lash on the intake valve.. rotate engine working on the same cylinder, then as intake valve starts to close, adjust lash on the exhaust.. its that simple..
 

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dub,

In the "good-ol-days" we called this method "Valve Rock" So when one cylinder is at "valve rock" the cylinder opposite it in the firing order can be adjusted both intake and exhaust. So if you put #6 cylinder at VR you can adjust #1. then to adjust cylinder #8 you turn the crankshaft so that #5 cylinder is at VR. I hope you get the picture.

Scholman
 

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EO/IC Method (Exhaust Opening/Intake Closing)
In order to adjust the preload, the lifter must be properly located on the base circle or "Heel" of the lobe.

At this position the valve is closed and there is no lift taking place. You will need to watch the movement of the valves to determine when the lifter is properly positioned for adjusting.

1. Remove the valve covers, and pick a cylinder that you are going to set the preload on.

2. Hand rotate the engine in its normal direction of rotation and watch the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder's intake rocker arm. (Why? Because when the exhaust valve is just beginning to open, the intake lifter will be on the base circle of the lobe- the correct position for adjusting the intake.)

3. Back off the intake rocker arm adjuster and remove any tension from the pushrod. Wait a minute or two for that hydraulic lifter' push rod seat to return to the "up" position. The spring inside the lifter will move the pushrod seat up against the retaining lock if you give it time to do so. (If you are installing brand new lifters they will be in the "up" position when they come in the box.)

4. Now spin the intake pushrod with your fingers while tightening down the rocker arm. When you feel a slight resistance to the turning of the pushrod, you are at zero lash.

NOTE: If you are uncertain that you are feeling when all the lash has been removed (the "zero lash" point), jiggling the push rod up and down can give a better sense of when all the clearance has been removed.

5.Turn the adjusting nut down one half to one full turn from the zero lash point. Lock the adjuster into position if using polyloks. The intake is now adjusted properly.

NOTE: If using stock-type lock nuts, be sure to use new lock nuts; old lock nuts can back off and the preload will be lost. Do not use stock type lock nuts on aftermarket studs or the threads will be damaged. Follow the manufacturer's instructions.

6. Continue to hand turn the engine, watching that same intake. It will go to full open and then begin to close.When it is almost closed, stop and adjust the exhaust rocker arm on that particular cylinder. (Again, when we see the intake almost closed, we are sure that exhaust lifter is on the base circle of the lobe.) Loosen the exhaust rocker arm and follow the same procedure described before in steps 3 and 4 to adjust this rocker arm.

6. Both valves on this cylinder are now adjusted, and you can move on to your next cylinder and follow the same procedure again.

Something that you also might find useful, is go to How To Make A Timing Tape. This temporary timing tape will allow you to check and set the total timing even if you don't have a timing light that reads advance or a degreed damper. You can also use it to permanently mark the damper for full advance, etc. as you see fit.

If there's any doubt as to whether or not the timing mark on the damper and the timing tab is accurate, refer to Determining top dead center.
 

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F-BIRD'88 said:
Use the intake closing....exhaust opening method.

google it
I would do that method to get it close for start up.

Once everything else is checked out, then bring it to operating temp and set the valves engine running. some people even place the engine in drive, engine running and set the hydralic valve adjustment against the parking brake.
 

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Discussion Starter · #7 ·
Wow guys, Thanks for the great info, Ive been on a couple of chevelle only sites and they act like I have the plague or something. I appreciate all the info.

Thanks again.

Mike
 
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