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I m not going degree i want to set it by hand like the other link says
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Honestly i am in clas 1. Becouse here in holland they dont know so much as you guys in the us . I am a welder no mecanic or what else . My hobby is my van i want to learn things over a v8 engine. But in holland its diffucult to. See a person. Who has the know of the engines like you . So i ask (whit the best english i can) To you guys how to do it.i get a paper from edelbrock. Which says do not pump them up. I was looking on the web what pumping up means. And i found out there are people says yes do it end people no do it not .
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For not pumped up: - Adjust the nut just to the point where any free lash is taken up. You're going to be checking against the spring that want to push the plunger up against the retainer bail or clip so this a bit spongy in feel, it is not necessary to tighten to where the push rod is clamped and cannot be moved at all, this has the plunger bottomed. An advantage to this processs is that the valve will not be opened very far till oil pressure builds in the engine so the lifter to lobe interface will not immediatly be exposed to full spring pressure for a few revolutions. For pumped up: - Adjust just till there is just no lash perhaps even a couple thou loose, although for lifters using the wire bale rather than a circlip to retain the plunger running there is a risk of the bail comming out of its groove so this is not something you want to do for long. The plunger is being held against the retainer bail/clip by oil trapped under the plunger, the metering valve to this cavity needs motion to operate properly set the zero lash against spring pressure with the valve closed. If you set the lash a 1 or 2 turns of the retaining nut it will hold the valve open a small amount which will make the engine harder to start as it will bleed compression until the lifters have been cycled enough to bleed off the excess oil trapped in the adjusting chamber alowing the valve to seat. Of course the cam and lifter interface will see full valve spring pressure from the get-go and these days with break-in of the cam being so critical avoiding this situation could be helpful for lobe/lifter life. The way a hydraulic lifter works is when engine oil pressure exceeds the closed valve spring pressure and a lash exists in the connecting hardware from the lifter to the valve stem tip, the metering valve in the bottom of the plunger is opened by engine oil pressure allowing the cavity between the bottom of the plunger and the lifter's intenral bore to be filled with oil. As the lobe lifts the tappet against the valve spring the metering valve closes trapping the oil in the cavity locking the plunger to the lifter body thus transmitting the motion of the body to the plunger. These opposing forces keep the plunger within the initial adjustment range. The lifter if fully pumped up by the installers action or if in operationthe engine is run at an RPM where the lifters have pumped-up; the only way the lifter can re-establish a proper zero lash position is by cycling off and on and off the lobe. Some lifters have a built in leak like the Rhoads of other anti-pump up lifters and will bleed back down till the valve is closed without cycling, some lifters that shouldn't will still leak enough to do this. All of these leakers that do so by design intent or not are the lifters you hear clatter on a cold start in the morning. Bogie |
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Wezz
![]() The reason you degree a cam is to verify spec.s (a problem with machining), And some cams are ground advanced moving your power band to more bottom end You verify if it is or not, you can also lose a lot of compression depending on where the cam is installed! also a lot of timing chain sets are set up advanced even the 3 key way gear types can be advanced and some straight up! So you degree a cam to set it for when you want the power to come in at a particular R.P.M.! If you install a cam with an advance already in it and gears advanced you can really kill all your mid or top end power!! They sell advanced and retarded wood-ruff keys and other devices to move the degree point! for true power you don't just stab a cam in It, it may impress you when running but you will never know how much power you have missed! Always check the manufacturer of the timing set if the main key way is advanced or straight up! Some builders set them up advanced because as the chain stretches and wears it retards slowly through time and gets closer to straight up position! Jester Last edited by painted jester; 01-31-2013 at 01:09 PM. |
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![]() I'll add: The lifters that are holding pressure can set for a week or more and still be holding pressure keeping a valve open while the leakers slowly loose pressure letting the valves close! Ive torn down engines after setting for years in the woods that had lifter that still held their pressure! Jester Last edited by painted jester; 01-31-2013 at 01:19 PM. |
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Bogie |
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Ok: If you understand what bogie and I posted , that a lifter can hold pressure for a long time with valve spring pressure on it!!! And you pump them up and install them they can hold this pressure during your dry assembly! So when priming the engine they are already filled and holding the valves at max because you filled them already! Now when you first start the engine and quickly bring it to 2500 rpm a few lifters might hold valves open (till the lifters metering system bleeds some oil) causing loss of compression delaying start up and as the engine cranks your break in lube is being rubbed off your lobes and lifters you then can cause damage to the cam and lifters! But if your lifters are installed not pumped up and you do your engine prime with valves set at initial adjustment, as you turn engine over by hand while priming the gallys, the lifters will fill to running position because they have valve spring pressure being supplied to them! You hit the key and your engine has compression from the get go! No delay no rough running till they bleed off! If you have very close tolerances and the prepumped up lifters happen to hold the valves open a hair too much you may have slight contact and bend or damage your valve train!
100,000 people may never see a damage caused by pumping up their lifter before installation but if you are the one in the 100,000 that does you will wish you read and followed directions ![]() Jester If you don't understand Im sorry I tried to type it as simple as I could Maybe someone can explain it better then I. I understand it and know what I am trying to tell you so it looks good to me
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So the savest way is to not pump them on. Like the edelbrock say
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In my opinion yes! especially if your a beginner and doing your own adjustments 0 or a couple of thousands lash initial adjustment before start up is tougher then a fractional turn of the rocker arm nut for a beginner
Put your country and age in your profile Wezz ![]() Jester |
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Ok thanx for the good explains
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What you really need to worry about is breaking in the cam correctly. |
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I don't know what type of lifters you use, but I can take any of the new lifters I have here (Edelbrock at the moment), pump them full of oil and put 50 lbs on them and they'll bleed down. Edit- I had to go back to see what even brought this all up in the first place. Seems it was because someone said that pumping up lifters would destroy the engine. The reason I posted in the first place was to put that notion to rest- NOT to say "pump up lifters". In fact you'll never hear me recommend it. If it has to be asked whether to do it or not tells me there's no experience w/doing it. But one problem that new builders have is feeling when they're at zero lash. Hard to do even when jiggling and not twisting the p-rod until you know what to look for. So a lot of guys get this wrong- and end up bottoming the plungers and then adding preload, lifting the valves off the seats. Then the engine cranks, and cranks, and cranks w/o starting up. So if having the valves off the seat for a revolution while they bleed down (even if this was necessary) will delay starting, what will having the valves cranked well and truly off the seats do? When the lifter is full of oil, one thing is sure- you can feel zero lash. Last edited by cobalt327; 01-31-2013 at 09:33 PM. |
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