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Topic Review (Newest First)
06-16-2012 10:24 AM
cobalt327
Quote:
Originally Posted by spinn
Tryingto figure out if that could occur by the method i use.

Not contradicting your information. Didnt mean to imply you said anythjing. Those are my theories, or what ifs.

My thinking , some engine revs up and drops oil psi. Then the plunger relaxes and creates this pushrod/rocker clearance . So you compress the lifter plunger with preload to allow a saftey margin for this occurance. Is this wrong, or do not get the prupose of preload?



Lose has one o. I think it is like look,or took. The oo sound in loose. Nevermind, stupid thought. Neither here nor there really.
Using your method (zero lashing w/o any preload) works. It has been used for years by racers who anticipate their engine will experience valve float, which is one main way for a hydraulic lifter to pump up. If there is no clearance to allow the plunger to pump up, there won't be any chance the valve will be momentarily held off its seat causing the engine to lose power, or worse.

Oil won't compress, so as long as there's enough oil pressure to replenish what is 'lost' to the top end through the pushrod (to lubricate/cool the rocker and spring), the lifter won't pump down. The way the valving is arranged in a hydraulic lifter, there is oil being released to the top end of the engine only during the time the lifter is dropping and the valve is closing. That is unless the lifter is an "edge orifice" type, which isn't seen much anymore.

Bottom line is there is no down side or loss of lift when using 1/2 turn past zero lash on a hydraulic valve train if the valve train is assembled correctly and the engine is operated within the design limits of its components. Unless of course you are using special lifters that require a different method to adjust, like some Rhodes and other fast bleed lifter designs.
06-15-2012 06:29 PM
joelster
Quote:
Originally Posted by ssmonty
I bet if you set them until they just stop making noise on a 90 degree day, that they will make noise on a 50 degree day.
ssmonty
Nope. You guys act like an engine shrivels when it's cold out. Adding a simply 1/8th of a turn is more than enough to compensate for any "growth" that can occur no matter what the material, aluminum or iron. My solid roller lash adjustment has a difference of .005 between hot and cold. That's an iron block with aluminum heads.
06-15-2012 03:20 PM
ssmonty I bet if you set them until they just stop making noise on a 90 degree day, that they will make noise on a 50 degree day.
ssmonty
06-15-2012 02:00 PM
spinn Tryingto figure out if that could occur by the method i use.

Not contradicting your information. Didnt mean to imply you said anythjing. Those are my theories, or what ifs.

My thinking , some engine revs up and drops oil psi. Then the plunger relaxes and creates this pushrod/rocker clearance . So you compress the lifter plunger with preload to allow a saftey margin for this occurance. Is this wrong, or do not get the prupose of preload?



Lose has one o. I think it is like look,or took. The oo sound in loose. Nevermind, stupid thought. Neither here nor there really.
06-15-2012 11:39 AM
cobalt327
Quote:
Originally Posted by spinn
So theortically if i run up to 5000rpm , and do Not use the extra 1/4 turn. My lifter will bleed down and loose lift? Cause i dont see it happening at idle or cruise.
I don't know where you got that from. I said above "It would only lose lift if there was clearance between the pushrod and rocker arm." In other words, if the cam, lifter, pushrod, rocker arm, and valve tip have zero clearance between them, there will not be any loss of lift. BUT- if there is any clearance between the parts, that will reduce the lift.
06-15-2012 09:57 AM
spinn So theortically if i run up to 5000rpm , and do Not use the extra 1/4 turn. My lifter will bleed down and loose lift? Cause i dont see it happening at idle or cruise.

They want that 1/4 turn or full turn in case it bleeds down, creating lash/space between. Then lifter plunger/internalspring takes up the space from collapsing lifter. Or something. On a light spring rate valvetrain and mild cam is this even a reality?

When the lifter stops ticking while i set it running, the plunger should already be slightly depressed. Maybe that IS the perfect amount of preload.
06-14-2012 07:46 PM
cobalt327
Quote:
Originally Posted by spinn
If there is oil pressure in the lifter, and zero lash, how is it loosing lift?
It would only lose lift if there was clearance between the pushrod and rocker arm. Any lash will be subtracted from the valve lift- just like if it was a solid lifter valve train, the solid lifter valve clearance is subtracted from the theoretical lift.
06-14-2012 07:22 PM
spinn Nah, hydraulic are easy to set.

It is this preloading that have me asking questions. I cant believe you want the lifter plunger in the middle. if you have cleaned out a lifter you know what im talking about.

All my past works of performance i used something like this for a gm inital startup adjustment. Just to get it close.

At TDC position Adjust intake valve on cyl Adjust exhaust vlave

1 2 8
8 1 4
4 8 3
3 4 6
6 3 5
5 6 7
7 5 2
2 7 1

This is just putting it together to start and break in. Then you adjust up with it running loosen till ticking then tighten to slowly till it goes away.

There was a nice lady involved and wanted it to not come back. The preload info does have me thinking.

You want it to wipe down the center and 90deg angularity. Adding .040" lift isnt going to change angularity much. Add .1" lift and start looking for pushrods.
Guides hole can be enlongated / chamfered?
Hittinng the retainer is a podiblilty and spring coil bind from lift. But rocker to spring is hard to come by.
06-14-2012 11:30 AM
Irelands child It looks like there must be a different way for everyone as far as adjusting rocker arms. Today I'm in the process of converting from pedestal to stud mounts via a Crane mod and Comp roller rockers on my Ford 5.0L. I've asked opinions on a couple of different Ford specific sites - you guessed it, now with the one above (which at least wasn't my question this time) up to five with more coming most likely before my day is over. The methods that make the most sense are the ones that put the lifter on the base circle then do the adjustment. Of course, and to confuse the issue is push rod length and where the rocker roller rides on the valve stem and plus whether the rocker will hit the retainer or even the valve spring. Almost makes me wish for a mechanical camshaft, shaft mounted rockers and feeler gauges
06-14-2012 06:54 AM
35WINDOW I thought I knew how to adjust Hydraulic Lifters, but I recently bought some Morel Lifters for my Car and was perusing their website and came upon this:

"Adjusting the Zero-lash setting of the Lifter:
1. I always like using the firing order to set the valves. Put the engine on #1 cylinder.
2. What we want is the int. and exh. to be on the base circle of the camshaft.
3. Adjust the rocker until the push rod just starts to get tight while taking the pushrod and rolling it between your thumb and finger. Once you feel drag, this is what we call Zero-lash.
4. You are now ready to tighten down on the adjuster using the following method:
a. It is important to know the thread pitch, in threads per inch, of the adjuster nut, because one complete turn of the nut will move a distance of one complete thread. Therefore, verify the thread pitch of the adjuster nut, because racing rocker manufacturers use different nut sizes and thread pitches.
b. If your adjuster nut is 7/16 x 20 threads per inch, then divide 1 inch by 20 threads per inch. One complete turn down on a 7/16 by 20 adjuster nut will move .050".
c. Next, divide .050" divide by 4 to calculate the distance for a quarter-turn of the adjuster nut (.050" / 4 = .0125").
d. For a 3/8 x 24 adjuster nut, the calculations are: 1" / 24 TPI = .042" per full turn and .042" / 4 = .0105" per quarter-turn.
e. Use the chart below to determine how many quarter-turns to tighten the adjuster nut after Zero-lash:
Cast Iron block and Cast Iron Head = .020" - .025"
Cast Iron block and Aluminum Head = .030" - .035"
Aluminum block and Aluminum Head = .045" - .050""
06-13-2012 10:23 PM
spinn If there is oil pressure in the lifter, and zero lash, how is it loosing lift?

About the oil squirting, I am starting to think that the valve train geometry was incorrect. With such a mild cam i dont know. Oil pressure does that? not bad valvetrain geometry pinching the rocker bleed hole, and increasing the pressure there ? Once the rockers were loosened they all oozed evenly. No noise cold or hot.

The little things are nice to know.
06-13-2012 05:36 PM
cobalt327
Quote:
Originally Posted by spinn
Thanks.

A full turn after the ticking stops . Really? What would be the reason. Depending on the rocker stud thread I would think that would lift the valve and give you problems.
The basic idea is to set the lifter plunger to the center of its travel. That gives the most leeway for temperature expansion/contraction. The old manuals for a SBC said anywhere from 1 to 1-1/2 or more turns after zero lash, but this has largely been replaced by using 1/2 to 1 turn total. For instance, Comp Cams recommends 1/2 turn for regular SBC lifters. The amount of turns needed to set the plunger in the middle of its travel will vary from engine to engine, because of differences in the thread pitch, rocker ratio, and lifter design.

What you have done is in essence zero lashed the valves. Not usually a problem, but there may be a bit of noise from the lifters if there is any lash when the engine is cold. If there is at least some preload, there should not be any unnecessary noise.
06-13-2012 05:16 PM
hpete The lifter adjustment doesn't cause the oil squirt, oil pressure does that. Without the extra quarter turn the lifters will be a little softer at low rpm, this may trim a little lift and duration again at low rpm. This may or may not be a good thing, it's kind of a poor mans rhodes lifter.
06-12-2012 09:10 PM
spinn Thanks.

A full turn after the ticking stops . Really? What would be the reason. Depending on the rocker stud thread I would think that would lift the valve and give you problems. He had the rocker so tight the oil shot out from the rocker like a jet. A little splatter is expected. What is scary is he tried to drive it like that.

Also for a high school kid, a 15 second flat car is fast. Dont understand what he was upset about. A stockish 79 camaro 350 / th350 with a K camkit, is not going to cut into big block territory 13's.
06-12-2012 07:50 PM
DoubleVision With it running is always how I adjust them, this is how I can tell what the engine likes. How I adjust them is back off really slowly until it ticks. Then tighten really slow until the tick stops, then give it a quarter turn. I've seen guys go half turn, 3/4 turn, full turn, you name it. There's another trick called "Zero lashing" hydraulic lifters but since it involves more time and makes a mess I only do so on the ones I build and don't recommend it to others. I've learned so much about valve adjustment I can do it without oil squirting everywhere.
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