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  #16 (permalink)  
Old 06-09-2010, 07:12 PM
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Quote:
Originally Posted by BBCMudbogger
I understand the OP to have a hydraulic roller cam if the wear is uneven enough to make any difference I would have bigger worries than how to adjust the valves to compensate.......and in the quoted post above if by "full" roller you mean solid roller then you are doing it wrong.Valvetrain noise isn't the way to select engine oil weight....LOL

My mistake, I should have been more clear, I have hydro's I'm still trying to get the lingo correct. Flunked englihs in high skool. I can't seem to post anything here without being corrected.

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  #17 (permalink)  
Old 06-09-2010, 07:42 PM
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Quote:
Originally Posted by Fast 4 Door
My mistake, I should have been more clear, I have hydro's I'm still trying to get the lingo correct. Flunked englihs in high skool. I can't seem to post anything here without being corrected.
Actually, "comp 270 full roller" has nothing to do w/hydraulic or solid lifter type- EITHER type lifter can be a part of a "full roller" valve train- "full roller" only means that the rocker arms have roller trunnions and tips, and that the lifters are rollers. Some might say the cam bearings can be roller bearings, too- but this isn't necessary for a valve train to be full roller.

So your description- provided that you have roller rockers AND roller lifters- is fine.
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Old 06-09-2010, 07:57 PM
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Quote:
Originally Posted by Fast 4 Door
My mistake, I should have been more clear, I have hydro's I'm still trying to get the lingo correct. Flunked englihs in high skool. I can't seem to post anything here without being corrected.



I apologize for the sarcasm in my last post, Just seemed to me like BBC had nothing better to do than try to make me look stupid . After all, if I were to crank down on some solids like that, I don't think I would still have a motor to talk about. And just for the record, I' m just trying to sharing my experience. Not school someone.
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  #19 (permalink)  
Old 06-09-2010, 08:41 PM
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I mostly just signed up here for these little smiley things>> < I really do like these things.. Sometimes when it's all been said these things are better than words
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Old 06-09-2010, 09:25 PM
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valvetrain

Quote:
Originally Posted by Fast 4 Door
My mistake, I should have been more clear, I have hydro's I'm still trying to get the lingo correct. Flunked englihs in high skool. I can't seem to post anything here without being corrected.
I've been following the thread and it seems that Sooper is just experiencing what alot of us have on different valvetrain issues. Fast4Door,I don't think anybody is talkin out of line here or trying to make anybody look stupid.

I will occasionally correct someone if what they said was dyslexic(backwards) or if the wrong terminology is used, but the intent isn't to belittle anybody just set the record straight on what is fact.

Sometimes folks have an opinion on the fix for a given problem, but sometimes the fix isn't always the same for a given problem. I think sometimes folks are a little paranoid on the forum and bite back at someones statement. This turns in to an argument that didn't need to start to begin with. This leads the OP into being paranoid about posting because he got into an argument over something he said that was just his opinion.

This leads into nobody wanting to post which makes the forum boring.

Okay, Back to the valvetrain thing. I'm speak from years of fixing valvetrain issues, not some intimate knowledge of valvetrain dynamics.

Everything everybody has said here has substance to it.
I THINK that lifters don't all hydraulically harden at the same amount of plunger travel. I have found stock lifters to need a full turn to function correctly or you give up lift. In other words it seem like the lifter is moving up with out lifting anything until the travel is satisfied for it to hydraulically harden. By the time it finally starts getting the valve to open, its already hitting the other side of the lobe and going down.
This results in a really soggy running engine if you're only using a 1/4 or 1/2 turn of preload. Keep in mind we're talking stock cam and lifters.

Every hydraulic high performance cam and lifters I dealt with would not tolerate a full turn of preload with out pumping up and staying pumped up( never bled down and was holding the valve open) I finally figured out that stock cam adjustment doesn't work with HP cams.

After trying adjusting them while running and cold before startup and found that 1/2 turn always seems the perfect adjustment. In fact, I've finally mastered perfect cold adjustment and can adjust a fresh engine, bolt the valve covers on and not have to take them back off. But every so often you have some settling of clearances in the pushrod seats and the head gaskets that requires a readjustment. I've found that fel-pro perma-torque gaskets eliminate the need to re-torque and loosing valvetrain clearance.
I use Comp products pretty much exclusively at least on about the last 6 engines I've built and they say 1/2 turn is approx. .030" and it worked perfectly for me on flat tappet and roller hydraulics. I use the spin method on the pushrods and have gotten alot better than my first try with pre-adjusting.

A comment on economy rebuilt engine valvetrain, I've found a few 350's about impossible to adjust till quiet. Seems like the economy lifters, valve springs, rocker arms and maybe some lifter bore slop, are just noisy even with perfect adjustment.

Sorry about the long post, but this comes up alot and I wanted to throw out my opinion on what works for me. Plus I'm sick right now and have time to sit awhile on the computer. olnolan
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Old 06-10-2010, 04:49 AM
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Quote:
Originally Posted by cobalt327
Actually, "comp 270 full roller" has nothing to do w/hydraulic or solid lifter type- EITHER type lifter can be a part of a "full roller" valve train- "full roller" only means that the rocker arms have roller trunnions and tips, and that the lifters are rollers. Some might say the cam bearings can be roller bearings, too- but this isn't necessary for a valve train to be full roller.

So your description- provided that you have roller rockers AND roller lifters- is fine.
Didn't mean anything by it thats why the word IF is in the post.
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  #22 (permalink)  
Old 06-10-2010, 05:08 AM
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This is an Excellent forum.. Duntov
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Old 06-10-2010, 05:20 AM
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Quote:
Originally Posted by BBCMudbogger
IF is in the post.
Understood.
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  #24 (permalink)  
Old 06-10-2010, 02:45 PM
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Quote:
Originally Posted by Duntov
Excellent Bogie!,
That read good, but I'm still unclear on a recommended adjustment. Sounds like you're saying they're more likely to pump up and jack valves open if treated like factory hydraulic lifters. You attribute that more to the cam lift/duration or to the aftermarket lifters? Thanks Duntov
Design:
A hydraulic lifter is an assembly of an outer body into which is placed an inner piston/plunger sub-assembly, and an inner spring that holds the piston/plunger assembly up against a retainer on the top of the lifter which forms a cavity below the piston/plunger and the inside bottom of the lifter body.

The inner piston/plunger assembly is made of the piston/plunger part which is hollow and has an oil entry hole in its side, a top called the socket where the push rod rides, under the socket is a flat disk inertia valve, at the bottom end is a check valve sub-assembly that contains a check valve which can be of a ball or disk design retained against a hole in the bottom of the piston/plunger body with a light spring and a retention cup that holds these pieces to the bottom of the piston/plunger.

The top of the lifter outer body is machined for an inner retention device that keeps the inner piston/plunger assembly from coming out. This device is a either a wire bail or a Circlip. Inside the bottom of the lifter body is a spring that lightly presses the piston up against the retention device at the top.

Operation:
Engine oil under operating pressure is fed into the lifter from a hole in the side of the outer body. This oil passes into the hollow piston/plunger where it goes in two directions: one, past the inertia valve under the socket to feed the pushrod, rocker, and valve spring with oil; the other past the bottom check valve to fill a chamber under the piston/plunger assembly pushing it up toward the retainer thus removing all clearance lash in the valve train. Engine oil pressure is not high enough to overcome the spring pressure keeping the valve closed, but is sufficient to remove the lash. When adjusting the rocker nut, the valve spring is strong enough to overcome engine oil pressure to allow the push rod to press the inner piston/plunger into the lifter’s body. Excessive downward adjustment will at the extreme press the check valve assembly into the bottom of the outer body damaging it. The adjustment is nothing more than depressing the piston/plunger an amount about equal to the heat caused expansion of the engine and its parts, it should be about the amount that a solid lifter clearance is set to as all you want is the lifter to operate where the piston/plunger does not pump up against the retainer with an exception I’ll talk about later, nor so much “clearance” that lost motion in valve train becomes enough to hold the valve open when the piston/plunger pumps up to remove excess clearance due to valve train deflections and spring harmonics.

When the cam lobe starts to push the lifter against the valve spring, the plunger sinks ever so slightly too where inertia plus the light retention spring closes the check valve trapping oil in the cavity below the piston/plunger and the inside bottom of the lifter body and closes the disk valve that controls oil flow into the pushrod. This hydraulically locks the inner piston/plunger to the outer lifter body. Continued rotation of the lobe then pushes the lifter to where it actuates the valve train to open and close the valve. This is one place where a small amount of lost motion occurs as the inner piston must initially move fractionally slower than the outer body. This is done by allowing a tiny amount of oil to leak out while the lifter is rising on the lobe’s ramp.

When the lifter comes off the closing side of the ramp, the loss of valve spring pressure allows the internal high pressure trapped oil to push the check valve open as well as the disk valve to the push rod and escape. Oil then flows to the rocker mechanism and into the lower cavity till the cycle repeats on the opening ramp. If during this part of the cycle a “clearance” appears due to bending of the push rod, rocker stud, or floating or sticking of the valve; the plunger under engine oil pressure will react to close any clearance until it meets with valve spring pressure. If these events occur the piston/plunger will position itself higher than its initial adjusted position. If the next cycle of the lobe gets to the lifter before it can bleed the excess oil out from the force of the valve spring pushing backwards on the piston/plunger assembly; the base point of the piston/plunger will start that much taller as it hydraulically locks itself for the next opening cycle. Then when the lifter comes off the lobe, the valve will be held off its seat, unless the lifter has enough cycle time to bleed the excess oil out of the lower cavity. This is pump up, it occurs because something in the valve train has put either a clearance by deflecting under load, a loss of valve control from spring surge, or a momentary time lapse against function as in a sticking valve. By adjusting the plunger/piston lower in the lifter body, you increase the hydraulic lash, which at pump up will increase the amount of distance the valve will be positioned above its seat. This, also, increases the time and number of RPMs that must be reduced in which it would take the lifter to bleed down to recover from a pump up situation. So to a very large extent, the lifter’s ability to hold the initial zero lash adjustment is dependant upon when the check and disk valves close and how tightly they close.

The response time and amount of a lifter’s ability to track with the cam profile is directly related to how radical that lobe profile is and the amount of valve spring pressure that pushes on it. All hydraulics have some amount of “leak” down and a response time to recover that on the back side of the cam. There are lifters such as the Rhoads' that have more leak down than would a production lifter in a grocery getter engine. Crane and Comp also utilize fast leak down lifters to the same purposes which is to obtain a faster recovery from a pump-up situation and to build in an amount of RPM dependant variable cam timing. The latter is used on hot cams which tend to kill bottom end torque where a reduction of duration and lift at lower RPMs tends to bring the torque curve peak to a lower RPM and to hold that peak over a boarder rev range which provides more low speed power without resorting to high stall converters and or stiffer rear end gearing. But the down side is these lifters tend to tick at low RPMs where the downward movement of the piston/plunger does not have time to recover to zero lash on the cam heel because of the designed in leak rate. But as RPMs come up, the plunger runs out of time on the lobe to sink as much as at low revs, so the lifter nearly returns to its adjusted zero lash state by its normal operating process of viewing the high leak down as a distance of lash to be taken up. But these type lifters always leak the piston/plunger a bit more than the OEM type so they will extend the operating rev range before pumping up, but always at the cost of a tiny bit of duration and lift at the valve against the theoretical events commanded by the cam. This is where a solid lifter always carries an advantage.

As I said back at the first paragraph of the Operation section, there is a situation where you can push a hydraulic to function more like a solid. If the piston/plunger retention device is a Circlip instead of a wire bail, it is possible to adjust the lash so it is just at zero lash with the engine hot to where the piston/plunger assembly is just touching the retaining Circlip. This will prevent the lifter from pumping up to where it holds the valve off the seat as it takes up lash that develops from deflecting parts and spring surges. However, this can put a lot of load on the retention device which is why Circlips are recommended over wire bails. But bear in mind that a failure of the retention device will result in a messy, if not destructive, situation.

Bogie
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  #25 (permalink)  
Old 06-10-2010, 03:39 PM
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I agree w/ Duntov
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Old 07-16-2010, 11:24 AM
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With a 1:1 rocker ratio, .050" change at the stud (fulcrum) = .100" change at the lifter plunger (less a bit due to angles).

With a 3:1 rocker ratio, .050" change at the stud (fulcrum) = .075" change at the lifter plunger (less a bit due to angles).

With a 1.5:1 rocker ratio, .050" change at the stud (fulcrum) = .900" change at the lifter plunger (less a bit due to angles).

I Think, BBP

Last edited by BUFFALOBILLPATRICK; 07-16-2010 at 11:52 AM.
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Old 07-16-2010, 11:56 AM
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Bogie,

Could you elaborate some on your: "Excessive downward adjustment will at the extreme press the check valve assembly into the bottom of the outer body damaging it"

From my investigation, some adjust their hyd lifters very close to the bottom, to keep high RPM plunger collapse from reducing lift & reducing seat bounce. David Vizard suggests this in one of his books.

Thanks, BBP

Last edited by BUFFALOBILLPATRICK; 07-16-2010 at 12:03 PM.
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Old 07-16-2010, 12:15 PM
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holy Old Post Batman!!!!!!!!!!!!!
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Old 07-16-2010, 12:26 PM
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Yep, 40 days, SOOO WHAT???????
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Old 07-16-2010, 01:17 PM
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Old Posts

Quote:
Originally Posted by BUFFALOBILLPATRICK
Yep, 40 days, SOOO WHAT???????
I'm wit Bill,
I like to revisit a conversation out of the past myself, and I was never picked out for ratiomatic neither.....
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