I'm just finishing up my cam swap. I primed the oil pump to fill the lifters. Then I marked off the HB in quarters so I could follow the firing order to adjust the valves.

I tightened the rocker 1/2 turn. I have Crane roller rockers. I followed Ede or Madmax (can't remember now) advice and tightened the nut 1/4 turn, then snugged the set screw, and then tightened the nut the other 1/4 turn so the thing would jamb real good.

After all said and done, I can still compress the lifter a bit when the lobe is on base circle. Is this correct?

 

also, am I cool using the same distributer I had before?

 

Astro,

If you primed the lifters adequately, you shouldn't be able to compress them at all. Have you tried the "spinning push rod" trick? (Spin the push rod to see if there is lash in the valve train.)

If you were using a roller cam before, and are using a roller cam now, the distributor gear should be compatible. GM hardens their roller cams, too. If the gear or distributor bushings are worn, that's a different matter entirely.

 

I had a flat tappet cam before. My friends T/A has the same distributer but that's not to say the gear is the same. Any way of telling which gear I should have on my dist?

Vader - thanks for helping me thru this, you've been a great help. -MIC-

 

I disagree with Vader... with hydraulic lifters correctly adjusted, you can almost always push the plunger down into the lifter when the valve is fully closed. In fact, the plunger has about .100" of travel; ¾ turn of preload will take up about half of that; with ½ turn preload, you should be able to push the plunger down about 1/16" by hand.

If you have a stock late-model distributor and a cam that is not billet steel, i.e. a street flat tappet or hydraulic roller, then your dist gear is compatible. Billet cam = bronze dist gear.

 

You shouldn't be able to when they're filled with oil.

 

RB,

I'm interested in your experience on this. Whenever I've had am oil filled lifter (with good check valves in the plunger) the plungers have been nearly incompressible. Maybe I'm just a weakling, and this is why I have better luck lashing the valves hot with the engine running. I've always got them close enough to start and run by using the cold method, but like to hot-lash to be sure.

I'm aware of the plunger travel in the lifter body, and it is usually just a little over 0.100" in effective range as you state for many lifters.
These Crane 99277 (anti pump-up) have 0.156" of plunger travel, for example:



I generally like to run these on the "loose" side, or closer to the top of the travel to prevent lifter pump-up and valve float at higher RPM/oil pressures. Regardless, I've never been able to compress them once they are correctly adjusted. Hmmm - I wonder what I'm doing differently.

 

how to set your valve lash with hydrolic lifters
rotate the engine with the proper tool until the exhaust starts to open. this ensures the intake lifter is on the base circle. adjust your lifter. rotate the engine until the entake valve is closing and adjust your exhaust valve. note - it is important that you adjust a valve when the lifter is on the base circle. if the exhaust is already fully open, or starting to close, then you may already be on the ramp opening the intake valve and result in an improper adjustment. you can also watch multiple valve action and do several at once, or jsut go one by one. the haynse(sp) manual has a procedure of puttingit at top dead center and adjusting I2 E3 E5 I8 and rotating a rev and adjsuting others. i can't remember the procedure so check it out. the individual metheod above will work fine.
how the actual adjustment is made
with the lifter on the base circle, rotate (spin) the lifter back and forth and tighten the rocker until it snugs and stops spinning. if you are he manning it or have a super tight grip, you will still be turning it after the snug point. loose and delicate. after it is snugged, the proper adjustment is to tighten 1 full revolution. many people run with only 1/2 to 3/4 turn to get a little more hp by preventing pump up, which is what i would recamend. some even run with as little as 1/4 turn past snug.
the blead down debate
i would say it all determines on what kind of lifters you have. if they blead down easily, then you should be able to compress them. if they have strong check valves, then probably not. remember that oil can exit out the side and get out through slightly worn lifter bores and oil also travels up the push rod to luberecate(sp) the valve train. in general i would be leary of this metheod because i see the potential for someone to tighten the lifter so tight that the plunger bottoms out because they can compress them. this, in essence, is turring a hydrolic lifter into a mechanical one which will be quite prone to valve float and possible pistion contact, depending on cam timing and clearance, when the lifters pump up to thier normal state.
jess

 

With normal lifters and engine oil of some sort in the lifter, its pretty hard to push the plunger down by hand unless something is wrong, at least thats been my experience. Now, with the light oil the lifters come with, they are extremely easy to push down.

I'm pretty ****, so I measure the preload with a dial indicator on a couple of the cars I have. Mostly the reason I do that rather than setting the lash while the engine is running is I cant hear the lifters hardly at all over all the other noise. I do think that setting them with the engine the best way for just about anyone to set the lash though, if you can hear them ok. Little messy, but effective. The spin the pushrod method can be dangerous if you dont know what you are doing or the lifters arent filled with engine oil. Some of those lubricants make it really easy to spin the pushrod and you're already well into the preload area.

1/4 turn with the set screw down? Did I say that? Seems like alot to me... although I cant remember ever having measured it, I usually just tighten the set screw and then give both that and the locknut a turn to where its nice and tight.

You might try adjusting them with the engine running, might be easier for you to do. IMO its the easiest and safest method if you can hear the clacking of the loose rocker ok.

 

Vader -

You're right, they can take a great deal of pressure to push down when they've been oiled, and sometimes go down only very slowly besides, as the oil is forced out. Usually the act of turning the motor over slowly by hand a couple of turns is enough to force the oil out to the point that they can be depressed.

I agree about the lash. I don't like to leave them at the factory spec, because when you do that, if the tension on the lifter from the valve spring goes away even for a brief instant during high-RPM operation, the oil pressure will force the plunger to try to take up the slack; this is what people commonly refer to as "pump-up". The only reason for having any preload at all is to allow the whole mechanism to expand to compensate for temperature changes, and wear; ¼ turn is plenty for that.

I usually do them by hand, by finding the max lift point on each valve with a dial indicator, and adjusting the one opposite it in the firing order (#6 intake max lift and adjust #1 intake for example), just exactly as I would do for solids. Then I add the desired preload. I usually use something like ½ turn on all-new valve trains, and ¼ turn on used ones.

 

I have set up various hydraulic roller motors & found even after priming the oiling system you can still compress the plungers. If the intake manifold is off, you can watch the plunger as you turn the adjusting nut, if it compresses, you have gone too far. Spinning the pushrod doesn't always work, depending if the lifters are pumped up enough or not. I move the pushrod up
& down while adjusting the rocker, just until it won't move. Of course the lifter has to be on the base circle of the cam. I then look at all plungers to see if any are pushed in after rotating the engine over. Double check my work & move on.

 

Wow...thanks for all the replies. This was very informative.

I've always heard that adjusting the lifters with the engine running is the best way. Unfortunatly I can't since I have to take my A/C compressor and Alt off to get the valve covers out.

I had them turned 3/4 turn and this morning when I started it they were clattering for a while. So I got in there and did another 1/4 turn. Then they were all quiet.

I also have Crane Roller rockers. Do these tend to be louder than stock stamped rockers?

 

ttt