Has anyone ever had any difficulty adjusting hydraulic lifters in a small block??? I have a stethoscope (mechanics), but wanted to know the best way to accomplish this. I have all of the directions for my 68 327 to find zero lash, but needed to know how to deflect the oil properly with the rocker arm covers off. Should I use Oil deflector clips (Mr Gasket brand)?? Or should I butcher up an old valve cover with the top cut off only??? Have any of you had any problems with adjusting lash, that is, mechanically after it is done???


Gonzo

 

I set them with the motor turned off and cold.
Remember when deciding where zero lash is you do NOT rotate the pushrod, you move it up and down.
I add 3/4 turn past zero lash.

 

Use a set of rocker stoppers (probably the same as your oil deflector clips). They clip onto the top of the rockers so that oil does not spray all over the place. Go to each rocker and loosen it until it ticks. Then tighten it up until it just stops ticking, then give it another 1/4 turn. If you overtighten, you will know it because the engine will run rougher. When you have adjusted them so that all of the ticking is gone, go back over each of them with the same procedure so that you know the ticking is coming from that valve. This way, you make sure that you don't have some overtightened.

 

thanks, one difference in your procedure from the 68 service manual is that after the 1/4 turn to tighten, then go another 1/4 every 10 seconds until a FULL turn is made from zero lash. Is this necessary, or will just a 1/4 to 1/2 turn do it efficiently?? Will rocker stoppers stop all of the oil from getting outside the top of the cylinder head??? I really want to use something that will keep almost all of the oil inside the head, since my block is prestine at this point. Is that possible?? I am a rookie at this, but want to tackle it efficiently, so I am going to ask a dumb question, their are 8 rocker adjustments on each side, 16 total, right??? I mean, do all 16 rockers need adjusting in the procedure you noted above???

Gonzo

 

although i dont agree with any of the responses, or this technique, you could cut a rectangular hole into the top of an old valve cover to stop the oil, and adjust your lash

 

thats the question I was asking in my first thread, which would be better, rocker arm deflectors, or a butchered up rocker arm cover (same as a valve cover)....thanks for your input My biggest questions are in thread #4, if anyone can answer all of them, I would be VERY greatful

Gonzo

 

"old school", but still effective. It's tough to do without any splatters, but this will do a pretty good job.

 

Gozo use both. That will minimize the mess. The clips will keep the oil out of your face and the valve cover will keep the mess from running down the side of the head toward the exhaust.

 

Good point, I guess I never thought about using both.....I didnt know it was that messy of a job....



Gonzo

 

FWIW - The clips help stop the oil from squirting out at you BUT the oil will still splatter out a bit as it flings off the tip of the rocker while the engine is running. The clips help and I have a set but a cut open rocker cover is a little bit better if you want to keep it cleaner. It helps if you have the idle speed way down.

Truth be told, I now just set them cold using my own procedure. Take up the slack so the pushrod does not move up and down loosely anymore plus a rough 1/4 turn. (If the pushrod is "tight" at this point, you have gone too far). The 1/4 turn preloads the plunger in the lifter but you want to avoid bottoming it out. Rotate the crank 360 degrees and check for any rocker arms that are now floppy loose. The few that will now be floppy loose get the adjustment repeated but the rest are left alone. A visual check of the exposed rocker stud threads will tell you if you are way off. The amount of exposed threads should be about the same for all rockers after the second go around.

Nobody else does it this way but it works for me. I have never seen a cam that has a lobe with so much duration that it is still on ramp when the cam has rotated 180 degrees. For the first go around you are either on the base circle or you are on a ramp - adjust them all. After you rotate the crank 360 degrees, the cam has rotated 180 degrees. The lobes that were on a ramp for the first go around will now be on the base circle for the second round and the rockers will be flopping around loose. Those are the ones that get tightened in the second round. Hydraulic cams ONLY here guys.

Do Not Try This At Home - Adult Supervision Required - Experiment At Your Own Risk - I Am Not A Professional, Just A Bubba

-Mark.

 

Using both is a good suggestion. The clips do not contain the oil enough to keep it off the block & floor.

When you set the rockers, you have to follow a pattern by rotating the crank.. I'm assuming you already know that.

I have found if you use the correct technique when setting the rockers cold/not-running, a "hot" adjustment is not necessary. I hosted a tech session at my shop a few years ago for some forum members and showed them "hands on" how to set the rockers... and as posted above, twisting the pushrods proved to be an inaccurate method, with a brand new set of rockers off the shelf. The internal & hydraulic backpressure exerted by the lifters was not consistent. It is this "backpressure" that causes the friction which determines when the pushrod stops twisting. The lifters that are loose have less backpressure, and you end up over-tightening these to achieve pushrod bind. Hence, the adjustment varied all over the map. Some were good, others were way off. In general, when you use the twist method, some rockers will be too tight, and you stand a good chance of having a piston tap a valve on startup.

I have repaired MANY engines that were damaged simply because of bad rocker adjustment technique.

 

(Cold Method) Everyones "feel" is different, so to eliminate all "subjectivness" that the push/pull or twisty method creates, place a .002 feeler gage between the rocker & valve stem. Tighten the rocker adjust nut till the feeler is snug...remove feeler....then tighten nut to the desired lash...
Eddie

 

Tom, Since you, Mark and Eddie set them cold (which I have never done, or had any instruction on this procedure), I would appreciate any insight (article, or otherwise) on how to get this done in a step by step process. Something like the title: "Valve lash for dummies".....Otherwise, their is an expert engine builder in my area that I could pay to get this done right. IT is not an emergency and I might be over-reacting over the whole thing, but I just want to get it checked, since their is a little noise (tapping, or clatter) coming from the engine after warmed up. The engine was rebuilt in 2002, and runs out great with no knocking, or detonation. Maybe I should leave well enough alone, I'm not sure right now....thanks for all of the advice!



Gonzo

 

I'm in the Norval camp. There is no reason to set hydraulic lifters with the engine running. Set the lash with engine off and cold. That will get you right where you need to be with no mess. I set all mine at 1/2 turn past zero, but 3/4 works fine, too.

 

I agree that the using the rocker stoppers is old school, but it is foolproof. I try to set my valve lash when it is cold, but some people fear that they will set it too tight or too loose and cause engine damage.

If you want to adjust them cold, Lars wrote an article on this for the forum. Here is the link. Valve lash adjustment

 

This is basicaly what my GM service manual says to do.

 

Thanks for the additional input, I will read Lars' article on setting valve lash and go for their....I will be sure to take my time in doing this procedure as I dont want to screw anything up. thanks again guys, I owe you all a beer, or whiskey (I prefer JD), whichever trips your tigger....

Gonzo

 

I'm an ASE Master Technician with over 25 years experence building/rebuilding engines..... These guy's are RIGHT!!!
I adjust mine STONE cold, let the car sit overnight cold!! No mess, done right the first time.

 

I've done it this way for 30 years without a problem. No mess. Sad to say, this is one of those subjects that many myths surround, and everyone you ask will have a different method.

Steve