Need some help here guys. Can someone elaborate a bit on exactly how to adjust a valve to zero lash, with no pre-load.

I'm installing a new cam and it's been awhile since I've done this. I know I need to rotate the engine in it's normal direction, until the lifter on the exhaust valve of the cylinder I am working on starts to move up. Then, adjust the intake valve on that cylinder to zero lash, with no-preload, then 1/2 turn more. (that's the part I'm not sure about, how to determine zero lash). Is it when the push rod becomes snug, but can still spin a bit?, then give it another 1/2 turn, and I'm done?

Thanks

That is correct. The instant it touches the valve is Zero Lash.

When I do mine I jiggle them up and down and also spin them, as soon as you feel any resistance at all and they don't jiggle anymore you are at zero lash. Then set your preload. Since you are installing a new cam it is easier to set the valve with the intake still off.

I just did this on mine on Monday, I wiggled them to no resistence up and down and did the spin thing and went 1/4 turn. Remember don't go back and check cause the lifters will bleed down and it will appear that it's loose again. Unless your runnig a solid then ignore that.

zero lash is exactly what it says ..."zero" . On a hyd cam zero lash is no lash (slack) in the pushrod and no preload. Preload is the extra 1/4 , 1/2 turn you tighten it down.

+1 to doing it with the intake off. Once you have the lifters pumped up with oil it is pretty easy to know when you are at zero - but with new lifters the only thing holding the cup in the lifter up is a small spring - hard to feel, but easy to see when it starts to move. That way you can confirm by feel and sight that you are at zero.

Thanks for the info guys.

That 'zero lash' thing is tough with new lifters that are not full of oil. It's REAL easy to go past the top of the adjustment and all the way down to the bottom if your not carefull. The easisest way i've found on an assembeled engine is to grab the back of the rocker and wiggle it up and down as you tighten the adjuster. You'll feel the end of the slop and know where to start your 1/2 turn preload adjustment.
If you have poly locks it's even easier than that. Get the lifter on the base circle (Exhaust opening / intake closed) and run the poly lock down with two fingers. You'll feel zero lash EASILY with just two fingers. Then add your preload and set the lock. Your done!

Sounds like doechsle has the same petpeeve as I. The is no 'LASH' in hydraulic lifters. 'LASH' is the clearance you set with solid lifters (flat tappet OR roller) but with hydraulics the only thing 'lash' is ZERO LASH,, and at that it is really just the point of ZERO preload... where you BEGIN to set your preload. I know,, it's just a terminology thing. But you'll find a lot more than just doechsle and myself will have raised eyebrows when someone mentions 'lash' when refering to a hydraulic cam.