I have been doing research on setting the lash and there seem to be a lot of methods. From what I understand, you have to set the lash while the lifter is on the base circle - which is about half of the cam for any given lobe. It seems to me that any part of that base circle is as good as any other part of that base circle - as long as the lifter isn't on the lobe. I have just replaced all the lifters and all of the pushrods. My intake is off. It seems very easy to tell where the lifter is - rotate the engine (by hand of course), if the lifter doesn't move, you are on some part of the base circle. I would think at any given time most of the lifters are on some part of their respective base circles. Why can't I set the lash on any given lifter when it doesn't move when the engine is rotated?

 

Are you dealing with solid or hydraulic lifters?

 

Your proposed lash adjustment procedure will work. You will, however, need a dial indicator tagged to the lifter on each valve as it is adjusted to make sure the lifter is in fact not moving.

Unless you're running some huge monster cam, the adjustment procedure in the Chassis Service Manual is a whole lot easier to do and works as well as any other procedure. The CSM procedure requires only four crankshaft positions to set all 16 valves.

 

Zero lash is usually 1/8-1/4 turn past just stop clicking. Zero lash is for hyd only.

To do it right, you have do do it with the motor running. I took a used steel valve cover and opened up the top so i could access the adjustment nuts, it keeps the oil mess down when tighten to the head with a gasket.

Doug

 

If you have hydraulic lifters your idea can work but the safest is to rotate the lobe away from the lifter to make sure you have true base circle to avoid mistakes.
Production Engine rebuilders will install a lifter and push rod with the lifter sitting on the base circle. They will install the rocker arm and start bringing the adjustment nut down while rotating the push rod with fingers only. When the rocker arm makes contact with the push rod the push rod wont rotate easily any more. At this point they will tighten an additional bit and they are done. The additional amount varies by builder. Some go 1/2 turn, some go 3/4 turn, some go 1 full turn. Each seems to work. If you go too much you will hang a valve open and that is not good. Once you have set a single lifter this way do not touch it again. On install you have one chance to adjust a lifter without the engine running. After you partially load a lifter it will not reset to the top of travel till the engine is running.
After a few moments the push rod will spin again as the lifter bleeds down, ignore this and work through all 16 till done then oil the rocker arms and put on your valve covers.
If you go back and try and adjust more you will end up bottoming out a lifter which will hang a valve open on start up so once adjusted don't touch that one again.
If you install one rocker and push rod at a time and adjust one at a time you will know where you are and when you are done. Very easy for anybody to do.
If you have a Solid Lifter cam these instructions don't apply and you need to pay attention to Intake and Exhaust and adjust for each on each cylinder.
With Hydraulics Intake and Exhaust adjust exactly the same.

 

I have hydraulic roller lifters

 

Thanks Avispa, the procedure detailed the CSM is what I was looking for. It seemed to me that you should be able to adjust more than one valve or cylinder at a time - I just didn't understand the valve train relationship enough to know which ones

 

I am a 1/4 turn guy myself....... I use the tighten till the pushrod does not turn, then rotate the engine and get the rest.

my car runs OK.....

 

Does not turn? I always move the pushrod up and down, and tighten the nut just to the point there is no more vertical slop, then go another 1/4 turn.

 

a newly assembled engine? Have these lifters been ""pumped up running yet""????????

Sounds like no, so you get them close with snugging them, then a 1/4 turn loose, I hope you pre-filled them, then go through it again, and then rotate the engine watching the sequence of which rocker is moving in relationship to the timing marks and cap off of the distributor and wiggle each push rod when the rockers are up on the firing (valves closed- no rocker pressure on push rod, because alot of people get out of sequence!!!) then fire it and adjust while running!

 

1/4 turn helps avoid pump up because you are leaving the lifter very close to the top of it's travel range. This can be helpful in sustained high RPM running. Production builders try and put the lifter in the middle of it's range so they have fewer failures. A failure could be a ticking lifter. For high revving engines the 1/4 turn is the best advice but be prepared if one ticks you are pulling the valve cover to find it and add another 1/4 turn to quiet it down. Production builders don't ever want to deal with that kind of come back. For a street driver that sometimes is revved to red line I would go at least a 1/2 turn.
In the 80's and 90's we moved lifters out by the pallet, some of the customers built 1,500 engines per week. Got a lot of feedback on what worked. As far as I know the internal lifter components are the same for both the hydraulic flat tappets and the Roller lifters. At least they were up to 2004.

 

and I am just a lowly ex-street racer who can build some mean engines and I know guys have their proven formulas for what they build, but for a recommendation to anyone new or novice, i would rather personally err on excessive pump up than too little preload and chancing the hearing of clatter at startup (clatter can be bad! Very very very very bad!!!!!! ) and you might not be quick enough to caught it or find it prior to doing damage. With too much preload, the valve is being held open to the max so you are just hurting cylinder pressure which is no big deal (also hurting vacuum)!. With some wiggle on the push rod with rocker up, you shouldn't have too much to hang the valve open which would be bad! Very very very Bad!!!!!!

Also it has been a long time since i have ran hydraulics (long long long time), but I used to adjust them using a vacuum gauge!

And then there is the listening hose or listening pipe methods or a combination of all of the above!

 

Ok, let me barge in and confuse u some more rg - well u asked for it. U got the sbc firing order 18436572. Now if u understand that a V8 engine has 2 pistons come to TDC every 90 degrees of crank rotation u will see it follows that firing order. When the dampner mark is on 0 degrees then both #1 and #6 cyls are at TDC. Only one of them is ready to fire with both vlvs closed (lifters on base circle) and the other has both vlvs part open in overlap (lifters on lobe ramp). So yes all u have to do is look at the vlvs and rocker arms to see which cyl is ready to fire with both vlvs closed and the 2 lifters will be on the "base circle" ready to adjust preload. Note the rockers and lifter must have some amount of preload to begin with to see this. If u are setting the rockers up for the first time then u need to just get some preload to start with to see which vlvs open - then u can adj it correctly once u identify which cyl is ready to fire.

Ok so saying it was cyl number 1 that was ready to fire w/vlvs closed and u adj #1 cyl preload. Now turn the crank counter clockwise (when standing in front of engine) 90 degrees. Look at your firing order and guess which cyls are at TDC now? Yep, cyls #8 and #5. And if previous it was cyl #1 ready to fire then now its cyl #8 (if it was cyl #6 it would now be cyl #5). Set your preload on the cyl ready to fire.

Now i think u can see what happens every 90 degrees of crank rotation and which vlvs to look at. Ok then next 90 degrees is cyls #4 and #7. Next 90* will be cyls 3 & 2. Thats one full turn of the crank for 360* and u still have four cyls to do. But now the opposite cyl is ready to fire. If previous was #1 it will now be #6 ready to fire. Next 90* will be cyl #5 and #8 at TDC with #5 ready to fire. Next 90* #7 ready to fire (adj preload). And finally cyl # 2 is at TDC ready to fire and adj preload.

Do it a couple of times on paper and u should have it nailed.

Last i roll/turn the p-rod with my fingers until no more up and down movement and maybe just a little drag rolling/moving side to side. Then i use 1 full turn preload on OEM hyd lifters (unless LS7 lifter which would be more like 1/4 or 1/8 turn).

BTW this is a copy and paste from another thread i posted this in - to much typing to repeat but it doesnt change for a sbc.

Hope this helps more than it hurts.

 

One more thing is setting dry lifters. If i was u i would take 1 new lifter and p-rod and try to depress that cup by yourself. U will find that lifter spring has quite a lot of force even dry and will leave a dent in a block of wood used to push on it with. But the rocker nut and stud thread have quite a lot of mechanical advantage and u can over adj preload just by turning the nut by hand/finger. Thats why u dont focus on the rocker arm when adj preload. Watch the p-rod and nothing else. When the p-rod stops moving up and down but can still be rolled around with your fingers then your at zero lash and can add your preload.

Thats all folks.