Ironxcross

comments, hints, suggestions, anyone???

Zeueses 97 RamAir

You do one at a time take rocker off put new one on tighten lock it down and start you can tell if it sounds right. then adjust dont tighten to tight.

BUBBA

My suggestion: Don't do it.

91RSLT1

Bubba,

Why is that? I find it easier to set lash with it running. The TDC method works but I seem to have better luck/results with the engine running. I have Crane gold 1.6rr, but to the original poster what RR, cam, springs, valves, are you stock? To me it sounds like you have none of the above, based on your sig.

BUBBA

It's just a suggestion: If you use the EOIC method and set the Preload--not lash---to 1/4 to 1/2 turns past 0 on all of your rockers, then you have them pretty much the same to start out. Then, if they are excessivelyl noisey, you can always run the engine and tighten them down a bit to quite them. An again they would probably require about the same amount of tightening, e.g. another 1/4 to 1/2 turn.

Just seems to be a tad easier than trying to adjust them when it is running, trying to listen to them, getting splattered with hot oil an messing up your nice clean engine.

Either way is going to work out. Hydraulic lifters aren't as fussy as solid lifters as far as lash v. preload, given the fact that setting a correct preload for maximum performance is desirable---a little more noise along with a little less preload may be worth it if you are in a speed contest.
JMHO

97s10ondubs

I always set them running, just put a piece of cardboard in the way so the oil wont splash out. I just tighten them each until they are quiet, then I go back one by one and do it to quiet then 1/4 turn.

rpm4lalo

I turn the car on and get them tight enough with my fingers for it to run at idle for awhile, once the engine is warm and still running of course I adjust my setup to 1/16 past zero.
1.6 comp magnums NSA's
Comp r lifters
7.20 1 piece hardened TF PR's
Isky Adj. Guideplates
7/16 arp rocker studs
PAC 1518 Springs

95camarodude

forget that do it with the car off and loosen them all. then set the to zero lash (which is when the nut stops on the rocker and then give an extra half turn. WITH CAR OFF if not be prepared to clean up the mess and some extra oil.

97s10ondubs

How do you know the lifter is not at the peak of the lobe? That idea is not accurate unless you know that the lifter is at the base of the cam lobe, hence using TDC method. I have done mine multiple times w/o making a mess so take advice for what it's worth.

BUBBA

The cam lobe associated with the valve being adjusted should be on the base when you use the EOIC method. I.e. when the Exhaust Valve just starts to open, you adjust the intake, and then you continue to rotate the the crank until the intake has opened all the way and is about half way closed and then you adjust the Exhaust Valve.

Obviously, you need to have the valve closed on the rocker that you are working on. If you start with the 1st cyl on the driver's side and complete that bank, then continue on with the passenger side until all the rockers have been adjusted, you should be damn close. And as mentioned, if they are still too noisey, you can tighten them up a tad.

It's a matter of opinion and choice, i.e., it's your mouth, you can haul coal in it if you want to.

FASTR

Ok, I had to deal with this many times with my race car and Ill tell you what I learned and you can decide what you want to do.

Ive built a few race engines, I ran them all with a hydraulic roller. I used to do the normal TDC procedure and use either 1/4 turn or 1/2 turn. Never netted me the results I wanted so I started doing it while the engine was running. No matter how you do this, it will be messy. I made aluminum "pans" or shields that fit on the edge of my heads with the covers off. This did help (and I used little clip-on blockers to plug the oiling ports on the rockers). Still sucked. If your not super fast and effecient its going to get real hot.. and still messy. Pissed me off. (for the record, you loosen the nut until you hear the clicking, then you slowly tighten until the clicking stops. Once you are at that 0 lash point you give it the 1/4 or 1/2 turn. With a nice lumpy cam, the "noise" is alot harder to distinguish. Your not quite sure where you are at)

I spoke with many different mechanics and engineers about this. The smartest thing I ever learned was from an R&D engineer at Crane Cams. (I am an engineer as well, so I relate to them much better).
He gave me alot of design theory, and the lash setting procedure he gave me was this:
Use the typical TDC method with the engine off. Rotating the engine accordingly and set the lash on the correct corresponding cylinders. Twist the push rod between your finger as you Slowly tighten the nut. As soon as you can not twist it, it is at 0 lash. I thought this sounded real subjective, but once you do it you realize its really easy to do. All of a sudden it just locks in. Once you are at 0 lash, set a dial indicator onto your rocker at the point directly over your pushrod. (I would use a magnetic base, stuck to the block in the lifter valley) Set the dial indicator at zero. Slowly tighten your nut until you get a value of .030" (thirty thousands). You now have the pintel (or plunger) pushed down in the lifter .030". This is an ideal setting for higher rpm use of hydraulic roller lifters. (Note: for this to work properly you need to have your lifters full of oil and/or primed. I would soak lifters in a bucket of oil for 24 hrs, which would fill them. After installing them, I would push on the push rod a few times and "pump" the lifter up before setting the rocker arms on. You want them stiff (or loaded) to properly set the .030" depth.)

After I started using that procedure it worked perfect every time. Its a little tedious, but MUCH easier than using your ear. Trust me!
I ran my big cam 383 to 6900 rpm with good springs and no rev kit.

Just my 2 cents
J

shoebox

If you wait until you cannot twist the pushrod, you are already past zero lash and the lifter is starting to compress. When you begin to feel drag on the pushrod is zero lash. If you are going to be so exact to use a dial indicator, you should at least start at zero.

Of course, with all the methods and the way people interpret and actually adjust their valves proves one thing-it's not so critical in most cases.

blue

I agree. Last time I did mine, some of them could be tightened down half way to the bottom of the lifter's range and still turn freely. I personally wiggle the pushrod up and down as I tighten to zero lash.

MikeGyver

Is this something one might need to do on a typical, stock, high mileage LT1?

shoebox

Stock hydraulic lifters will stay in adjustment for a long time. If you have never adjusted them, it might not hurt if you have nothing else to do.