I am slowly getting my motor back together after a cam swap. I saw on Horsepower TV where they adjusted the valves on a motor with the manifold off. All they really said was once both lifters are all the way down in the bore on one cylinder, you can go ahead and set the preload on those lifters. Is this really true? It seems like a really easy way to adjust the valves. This is a hydraulic roller motor.

Thanks, Erik

Yes, it's true. This is a very easy way to adjust valves particularly with hydraulic lifters as you can see the the amount that the plunger actually moves.

sounds like we are almost neck and neck Erik! just got done adjusting the valves on the 383!
mised you at the good guys show, we hit the drags friday and the show saturday. got some amazing pictures again this year!
now i just need a place to post them, hmmm.

personally, i always adjusted hydraulic lifters hot with the engine running. 1/4 turn clockwise after the clatter stops always seemed to get the most stable high rpms. but then again you DO need a baseline after a cam swap. in that case, poly locks are so sensitive you can pretty much feel zero lash, and as long as the cam is on the base circle, you'll be ok. if you want to get picky,add about .002 lash for iron heads and .004 for aluminum heads BEFORE preload as the warming engine will tighten tolerances a bit.
check out http://www.centuryperformance.com/valveadjustment.asp
for some excellent guidelines!
bet you'll be on the road before i am! ;)
Eric B

Eric, yes I did miss Goodguys this year. Hospice brought my dad home from the hospital on the 2nd of July and gave him 48 hrs. Hes still here today though, tuff guy.

I figured this was the easiest way to adjust the valves. I just wanted comfirmation of this before I start it. I will be on the road in two weeks for sure.

We need to hook up sometime and run them.

Later, Erik

i'll be looking at a gear change & some tires first!

glad to hear your dad is hanging in there, but i know how tough that can be too.

keep in touch!

Eric B

dont waste time adjusting lifters when cold- especially hydraulic-they bleed down.
get then close to start it up, then run engine to warm
get ready for a mess of oil everywhere
and tweek to just stop of the clatter of each lifter

It's interesting to me that the guys who adjust hydraulic lifters with the engine running don't do the same with solid lifters if this method is so accurate. You can adjust the hydraulic lifters perfectly on a cold, never started engine if you know what you are doing. You adjust them just like a set of solid lifters to zero lash, then tighten the lash 1/4-1/2 turn more. Zero lash doesn't mean collapsing the lifter, just the point where the slop is out of the valvetrain. You can tell this by the feel of the rocker arm when the lash is gone but the lifter isn't preloaded. If you tighten to the point where the pushrod gets hard to rotate, you're in trouble. Save yourself a mess and do it with the engine off.

Agree to the above,, providing you don't begin with a collasped lifter but you would know that prior to. You are working with lifter preload here plus the adjustment when doing this hot or cold but motor off. Adjusting hot/off you just compensate for heated surfaces. Anyone still use the P/G tool?

true, if the lifters have not bleed down...depennds on condition of lifters and maybe how long engine has been down, etc...

to add to thought, parts are moving when the engine is running, taking up tolerance slack between parts dynamically...
so static adjust will be close, but adjusting while running will be more accurate..
I adjust mine statically as best as possible and always go back and tweek when started - they usually need more adjustments

Here is the easiest way to adjust your valves/lifters with the engine off (solid or hydraulic). This works no matter how radical the cam is, unlike some other methods that you are "guessing" if the lifer is on the base circle.

1. Turn the engine the normal running direction (clockwise in this case). when the exhaust valve ofthe cylinder you are adjusting just starts to open (rocker just moves), then adjust the intake valve of that cylinder.

2. Once the intake valve is adjusted, keep rotating the engine the same direction watching the intake valve you just adjusted, take it to full lift (rocker all the way down), once it starts to close (rocker just coming up). Stop and adjust the exhaust valve of that same cylinder.

Repeat these steps until you have done all cylinders. Just remember exhaust opening, adjust intake. Intake closing, adjust exhaust.

Now with a hyd cam and the lifter empty, you have to be careful when checking for zero lash, do not twist the push rod between your fingers to feel for drag, gently pull up and down on the push rod until you fell there is no more slop (You do not want to start collapsing the linfter). Stop at that point and give the nut 1/4-1/2 turn more. If you follow these directions I promise you will not have any problem and will not have to adjust them again.

Sure doing it when running works but, you have to start somewhere. When I was a kid I used to do it that way and that's the way I was taught. There are better, less messy ways.

true, if the lifters have not bleed down...depennds on condition of lifters and maybe how long engine has been down, etc...

to add to thought, parts are moving when the engine is running, taking up tolerance slack between parts dynamically...
so static adjust will be close, but adjusting while running will be more accurate..
I adjust mine statically as best as possible and always go back and tweek when started - they usually need more adjustments

More accurate than what? What is tolerance slack? If I preload the cold lifter by 1/2 turn of a 3/8-24 nut on a 1.5:1 rocker it will be preloaded by about .031". How hot will the engine have to get to affect this setting by 10%? Can you tell the difference between being preloaded by .034" as opposed to .028"? If the lifter works best with a .040" preload, how do you measure that with the engine running? If you have solid lifters, how do you adjust them? Do you use an accurate method?

Typical hydraulic preload is from .020" - .060". GM cams are usually 1 full turn from zero lash cold. Comp cams are typically 1/2 turn from zero lash cold. The only way to mess up is not starting at zero lash. Royce mentions finding zero lash, I agree with him on not spining the pushrod...

The lifter has a spring in it so it shouldn't be collapsed unless some preload is placed on it. If unsure just back off on the rocker and start over by finding zero lash again.

Staying on topic adjusting the valves before installing the intake just allows visual confirmation the lifter is on the right part of the lobe.

More accurate than what? What is tolerance slack? If I preload the cold lifter by 1/2 turn of a 3/8-24 nut on a 1.5:1 rocker it will be preloaded by about .031". How hot will the engine have to get to affect this setting by 10%? Can you tell the difference between being preloaded by .034" as opposed to .028"? If the lifter works best with a .040" preload, how do you measure that with the engine running? If you have solid lifters, how do you adjust them? Do you use an accurate method?

not saying either method is the only way to go, as I am not a mechanic or engine builder, just an engineer who thinks too much...

these are just my thoughts, or theory and my reasoning why I like to adjust them while running....
Tolerance slack is "lash" between all moving parts.
if there werent tolerances, things would bind up when they heat up.
internals of bearings, between the rollers and cages, cages swell, shafts/rollers center themselves while spinning, etc.
so all the parts have tolerances that change, when they heat and also when they become dynamic - spinning when running, tolerances between parts grow and shrink throughout the system - total them up and you get dynamic slack.
so adjusting dynamically, you are able to take these tolerances into account, probably not much overall, unless your engine is worn.

Also, hydraulic lifters are just that, and oil pump,
they are designed to operate based on oil pressure of engine while running - they are charged up each cycle to full pressure - to take up this tolerance slack between the engine parts from wear over time..that is why there were designed.
this pumping does not occur when not running - when cold ,they are just at the last pump pressure or less, if they have blead down. so you are taking a chance and assuming they are fully charged.

And lastly, everytime I did them cold, I always have to go back and do again after engine warms up on a least a few.. I guess I am not an expert at static lifter adjustment..

I would think anyone who has to ask, probably is in the same boat...
and as a topper, my brother in law (truck mechanic) insisted as you, that static is the only way to go, had a hot shot speed shop adjust his lifters that way ....they were clicking and ticking the next day so he went back himself and adjusted them when running...

Hydraulic lifters are spring loaded, and will return to their maximum height when you release the pressure on them. Crane Cams has a nice article that explains the function of hydraulic lifters. A quote from them:

Hydraulic Lifters Can Be Adjusted at Any Engine Temperature

Since hydraulic lifters can compensate for thermal expansion of the engine, the adjusting can be done with the engine cold; hot adjustment is not necessary.

http://www.cranecams.com/?show=techarticle&id=2

IMO...
It doesn't matter hot or cold...period, end of sentence, badda-bing-badda boom. Looks like Comp Cams says the same...and they know their stuff!

If you can't adjust them cold because they tick when it runs, you aren't doing it right. There is not one single cam out there, whether it be stock or radical, that I couldn't adjust while cold and leave it there. I always had problems adjusting them cold, however, when I didn't use the EOIC method. Since then, it's never been a problem.

Matt,
until I start using the EOIC method I had trouble getting them right cold too. The main problem is you are guessing n if you are on the base circle or not. The more radical the cam the harder it is. using the EOIC method it doesn't matter how wild the cam is, you will be right on the money. I just taught this method to a friend who has been wrenching for years, he was having trouble with a 302 Ford getting the lifters set cold. I walked him through it and bam first try it was done, he had been through them several times using different methods and was still off.