valve adjustment
 

I set my valves on a new 502 by turning them 3/8 turn past zero lash on the heel of the cam. Now after I have run the engine through a heat cycle, the rockers seem alittle loose. (no ticking) I can spin the pushrods with my fingers on the valves that are closed. Is this normal

what are you running roller rockers or stamped steel stock rockers?
zero lash then 3/4 of a turn works perfect you need for zero lash when running.... 3/8 is not enough. start on the base circle @ each rocker are you running a adjustable valve train the new stock vtr is non ajustable u just torque them to spec.

adjustable --- roller rockers

Use 3/4 of turn after zero lash as stated. That is near perfect for the amount of preload needed.

Like these guys said, you need more pre-load than 3/8 of a turn. Some say 1/2, some say 3/4, so I adjust a little more than half. More like 5/8 of a turn. Crane used to have a good tech sheet on adjustment. Do a search you can probably find it.

3/8 of a turn will be o.k. - in fact if the valves ever float, the lifters will not pump up as far and you could avoid major engine failure. With the engine stopped (no oil pressure) you should be able to turn the pushrods where the valves are closed, not where they are open.

If you will read your books and read from almost all cam manufactures..they say 1 full turn after all the slack is out of the rocker arm.

Hyd lifters need about .040 of preload. 3/4 of turn after zero lash is about perfect to attain this.

Adjusting Hydraulic Lifters for Proper Preload

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 which 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 to return to a neutral 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 neutral 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". Turn the adjusting nut down one half to one full turn from that point. Lock the adjuster into position. The intake is now adjusted properly.

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.

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

valve adjustment
 

this was the way i learned years ago and is the easyest way to do it.i belive the method is called split over-lap adjustment

not necessarily. my comp .300 taller hydraulic roller lifters came with directions that went totally against everything I have ever known when it comes to adjusting hydraulic lifters. Comp actually reccomends 0 to 1/8 turn of preload after the push rod stops spinning saying that any more than 1/8 turn will damage the lifter? I dont know why I read the directions on this one occasion but I am glad I did lol:lolhit:

I too have replaced my lifters at just prior the 200hr mark and bought the higher rpm CompCam Pro Magnum lifters (#887-16) thinking they were better than the basic street lifter. Also reading the install sheet by chance and read about the 0-1/8 turn lash...???
Well as stated, I also have always done the 1/2 turn lash setting but did the 1/8 this time on these.
Have not had a chance to run the motors on the hose or in the water yet so I wonder who else has used the "high rpm" lifters at this setting and how it worked out?

Did a bunch of searching on the web and found that a lot of CompCam ProMagnum lifter users found best result with 0 to just off 0 lash. So I guess the high rpm style hyd. lifters need less lash over regular lifters that like 1/2 turn.

Fixx
 

Comp cam states that 1/4 turn is equal to .025..i don't believe in adjusting your lifters to 3/4 turn..you can only compress a hydraulic lifter .100 max then it turn into a solid lifter..lets say the retainer clip that holds the plunger comes out of the lifter,this will allow the lifter to pump up to its maximum lift capabilities and possibly allow the valve contact the piston..i have always used the 1/4 to 1/2 turn method so the lifter cant be pumped up the the max..This also allows the valve train to have more cush (between .050-.075),if you tighten them to 3/4 turn you will only have .025 of cush in the valve train..been dong it this way for years and never had any type of valve train problems..The more you preload the lifters the more they will pump up :)

After more talk with other engine gearheads using these im going to re-set at just past 0 lash.

Comp says 1/4 turn for .025 preload, but Crane says 3/4 for .040. Merc used to spec at 1/2-3/4 for the HP500's. Exact results will vary depending on lifter geometry and the exact amount of preload needed will depend on the lifters being used. I have generally done about 1/2 turn, snug the poly lock and then another 1/8 turn using Crane products.

I used the Comp. pro magnums #cca-875's on a sbc. I always adj. a 1/2 turn. Was amazed to read directions for 0-1/8 turn. Did the 1/8 and valve train is very quiet. Runs good too.

Good luck...hope it works for you.

Fixx
 

Wazz up jimmy:) how in the heck are you?

Take your time setting valve tr. and adj. will work out. Good luck. Let us know how it works.

I will. Got them re-lashed last night. Ran the oil pump and they are solid with no bleed down. I think just past 0 was the ticket.

Update...sorry so late.
Motors run the best they ever did...is it because of the new lifters and the just past 0 lash? who knows but im glad I lashed them to the spec sheet. They even idle crisper.