Adjusting hydraulic lifters
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==Overview== | ==Overview== | ||
| − | + | The following is based on instructions originally from Crane Cams. It is recognized by many as being the "go-to" method of valve adjustment. This method also works on any OHV engine using hydraulic lifters that has an adjustable valve train. The possible differences are: | |
| + | *the firing order | ||
| + | *the order of the valves in the cylinder head | ||
| + | *the amount of preload to use | ||
| − | + | ==A word on the amount of preload to use== | |
| − | + | Below are some things to check that could have changed the amount of hydraulic lifter preload: | |
| + | #Camshaft base circle diameter | ||
| + | #Pushrod length due to wear or replacement | ||
| + | #Milling heads/block | ||
| + | #Different thickness head gaskets | ||
| + | #Valve seat height changes from seat replacement or from valve seat grinding/cutting done during valve jobs | ||
| + | #Grinding the tip of the valve stem when doing a valve job or different length valves | ||
| + | #Lifter height due to different manufacturer | ||
| + | #Change in rocker arm type or design, or ratio | ||
| + | The recommendation given below to use 1/2 to 1 turn past zero lash is based on what has been shown to work well in the past when using stock or performance hydraulic lifters. However, the amount of preload may be different, depending on the type and brand of hydraulic lifters being used. For example, there are Comp Cams and Rhodes lifters that are set much as a solid lifter is set. Always refer to the manufacturer's instructions first before proceeding. | ||
| + | [[File:Hydraulic Lifter.jpg|frame|Generic hydraulic lifter]] | ||
| + | [[File:Lifter cutaway preload.jpg|border|400px|left]] | ||
| + | <br style="clear:both"/> | ||
| + | ==Firing order== | ||
| + | [[File:Chev sb bb v8 firing order.jpg|right|frame]] | ||
| + | |||
| + | ===You will need to know:=== | ||
| + | *The firing order of the engine you are working on. | ||
| + | :The Chevy V8 is <font size="4">1-8-4-3-6-5-7-2</font> | ||
| + | *The direction the distributor rotates. | ||
| + | :The Chevy V8 is <font size=4>CW</font> | ||
| + | *The order of the valves as they are located in the cylinder head. | ||
| + | :The Chevy V8 is <font size=4>E - I - I - E - E - I - I - E </font> | ||
| + | <br style="clear:both"/> | ||
==Adjusting hydraulic lifters for proper preload== | ==Adjusting hydraulic lifters for proper preload== | ||
| − | '' | + | ==='''EO/IC Method''' ('''E'''xhaust '''O'''pening/'''I'''ntake '''C'''losing)=== |
| − | ''' | + | *'''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. | |
| − | 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 | + | |
'''1.''' Remove the valve covers, and pick a cylinder that you are going to set the preload on. | '''1.''' Remove the valve covers, and pick a cylinder that you are going to set the preload on. | ||
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'''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.) | '''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 to return to | + | '''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.) |
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| + | '''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'''. (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.) Turn the adjusting nut down one half to one full turn from that point. Lock the adjuster into position if using polyloks. The intake is now adjusted properly. | ||
| + | <p>'''NOTE:''' If using stock-type lock nuts, no further action is required. Do be sure to use new lock nuts if using that type; old lock nuts can back off and the preload will be lost. Do not use lock nuts on aftermarket studs or the threads will be damaged. Follow the manufacturer's instructions.</p> | ||
'''5.''' 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. | '''5.''' 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. | ||
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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]]'''. | 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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== Adjusting lifters using a video presentation == | == Adjusting lifters using a video presentation == | ||
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Sometimes a video presentation helps to fill in the voids in describing a written direction of a project. [http://www.youtube.com/watch?v=89o5rLpbCgI&NR=1&feature=fvwp Valve lash adjustment video] | Sometimes a video presentation helps to fill in the voids in describing a written direction of a project. [http://www.youtube.com/watch?v=89o5rLpbCgI&NR=1&feature=fvwp Valve lash adjustment video] | ||
| + | ==Resources== | ||
| + | *[http://www.crankshaftcoalition.com/wiki/Valve_train_points_to_check Valve train points to check] | ||
| + | *[http://www.crankshaftcoalition.com/wiki/Category:Firing_orders Firing orders] | ||
| + | *[http://www.crankshaftcoalition.com/wiki/Category:Adjust_valves Adjusting valves] | ||
[[Category:Engine]] | [[Category:Engine]] | ||
[[Category:Adjust valves]] | [[Category:Adjust valves]] | ||
[[Category:Good articles]] | [[Category:Good articles]] | ||
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