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Discussion Starter #1
Got into a discussion about this with a buddy and we both are trying to figure out why you don't do it....was does priming do that is potentially so harmful to engine components?

What does a new primed lifter do that is so catastrophic? Inquiring minds need to know....

Thanks!

Rod
 

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Rod,

Well, they say... Priming new lifters can make them "solid" and make them possibly hit other things like pistons, I myself think it is a bunch of baloney. I prime my lifters and adjust thereafter, have always done "it" this way and have yet to have a problem.

BTW, my stick conversion is done.

Regards,

Bob
 

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it has been a long time but when I was in school I took an automechanics class and during rebuild we were instructed to prime the lifters?
 

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How would priming them make them any more solid than when they pump up from regular oil pressure?
 

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Hydraulic lifters have some "give" planned into them. If they are "over primed and act solid" That may cause some mechanical interference. I say it's BS myself...If you have measured for the right PR length, you will be fine.
 

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I have always primed my lifters. Most are anti-pumpup designs anyway. Even if they are not. If your clearances are that close I think you have other (potential) issues that is just waiting to bite you.
 

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Discussion Starter #7

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The reason priming is not a good thing is, any engine that has adjustable rocker arms and hyd. lifters, need a certain preload. Install lifters, pushrods and rocker tighten the rocker adj. until all slack is out and tighten another 1/2 to 3/4 turn or .050 preload. If you prime the lifters first, then when you try to tighten the rockers to get the required preload you will be trying to open the valve. I'm not saying you can't do it other ways, but that's what's recommended
 

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I have never primed them before, only soaked them in oil before install. Granted, I have only built one engine for my cougar that used hydralic lifters, but I had no issues. I have built engines for other people using the same method and had no issues then either.
 

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I have always primed them myself, but if you look at the crane cams web site on thier recommendations is not to..? My thinking is that I want to have a better idea that my valve train geometry isn't going to be an issue once they are up to near running condition. (Before I actually run it) If it causes an interference then you obviously have an issue and I don't see how that could be because you pumped them up since that would be the running state anyway??.. So I have no idea why they say don't? Must be a good reason, I just imagine it.
 

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Hi Rod, haven't seen you on here in awhile.

Lots of mis information on this thread.

Short answer..don't start the engine with the lifters dry. It's preferred to have oil in them before start up.

I don't have time right now for the long answer, but can post tomorrow if their's interest. Been doing lifter testing and development for way to long.
 

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I was hoping you'd chime in, Brian.

My short answer is that not all lifters are created equal. Go by what the manufacturer says to do.
 

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The long answer.

Lifters aren’t dry from the factory. They contain and are shipped with leak down fluid which is used to check the clearances from the factory before shipping. Leak down fluid is kerosene based and contains rust preventative and anti scent chemical. It’s very low viscosity to speed up the process of checking the leak down rate at the factory. The older leak down fluid had a distinctive smell and use to be referred to as birth control fluid in the factory. When you came home wearing that smell, no woman would touch you. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>
The grey area is it evaporates over time. OEM lifters usually get used within a couple months from production, so it’s not an issue. Aftermarket lifters will likely sit on the self for some time and the longer they sit the fluid will evaporate. Although, it still won’t be dry as the fluid in the high pressure chamber will not evaporate.<o:p></o:p>
<o:p> </o:p>
Basically, were talking about two different methods of priming the lifters.<o:p></o:p>
Priming them on the bench before installing them into the engine. Soaking them in a container of oil does nothing unless you stroke the lifter to ingest oil into it. My suggestion is if you want to fill the lifter with oil before installing it into the engine use a low viscosity oil. Transmission fluid works well. Submerge the lifter in a container of oil and stroke it using an arbor press to evacuate the air and ingest the oil into the oil feed hole. The lower viscosity oil will L/D faster and make setting the pre load once installed easier. Good method just make sure you use low viscosity oil. <o:p></o:p>
<o:p> </o:p>
Priming the lifters once install in the engine. The preferred method and what the different vendors will recommend. From Crane cam now S&S cycle web site which are our lifters. . “What is very necessary is the priming of the entire engine's oil system before starting up a new engine for the first time. This is done by turning the oil pump with a drill motor to force oil throughout the entire engine”.<o:p></o:p>
This will fill the low pressure chamber on the lifter and pre lube the vale train and bearings prior to starting the engine. NO, you cannot pump up the lifter and hold a valve open or cause any damage with this method. The only way a lifter pumps up is to have fluid enter the high pressure chamber and this can’t happen unless the lifter is being stroked. The only way a lifter pumps up is to take up lash in the valve train (which it’s suppose to do) and this can hold the valve open once the lash is no longer there until it L/D to the normal operating position again. Pre load on the lifters should be set before priming the oil system. <o:p></o:p>
<o:p> </o:p>
Keep in mind that lifters don’t pump oil. The oil pump supplies the oil and pressure to the lifters. The lifters meter or reduce the amount of oil going to the valve train. This supplies more oil to the bearings and reduces oil aeration in the system. Also cuts down on emissions as well. <o:p></o:p>
 
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Discussion Starter #15
Thanks Brian!

I've been chirping at you on different threads - thinking you might come back and look at some of the threads you replied to...

Anyway, hope all is well and thanks again for the detailed explanation. I'm sure there are a lot of folks that will be able to take advantage of your background on this subject - which I didn't know...

Rod
 

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Good info for sure - never heard about the trans fluid but I guess that does make sense.
 

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It would appear that I did perform it correctly then. I didn't mention earlier about priming the engine before start up, but would assume that everyone does. I have never started a new engine without priming it before. It seems to me that it make sense that priming the engine would get the oil in places that is needed in the lifters.
 

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I've been using a modified pump sprayer for years to prime. I was at the local parts store and noticed that they were selling a pump up oil priming unit. They were talking bad about it. They were saying that's what assembly lube is for. There's more to it than just lubricating parts. Newer motors have hydraulic timing chain adjusters. Someone warned me about the dohc requiring an unexpected 8 or 9 qts. or oil because of all the cavities and passages. I fill my motor with oil by way of priming on major repairs and check the dip stick. It takes longer fill the motor, but believe its good insurance. The only time I have ever had a problem with lifters is from starting the engine after cam and lifter change without priming the oil system. some of the lifters collapsed could have been low quality lifters But I suspect it was the rattle up start. It didn't sound good. The second time around I primed the system and it fired up instantly. It lived a normal life after that but start up is the most critical time for a cam. Stopping to tearing down to replace collapsed lifters always stuck in the back of my head. I prefer to set preload un primed. If I put the engine together I know where the piston to valve clearance is and have did rocker arms un bleed down with no problems. I have one motor out there with a big cam, big valves and pistons .004" out the hole it may be possible on a bad day something could happen if I hammer fisted it during preload adjustment.
 

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OK, the only thing that I grossly disagree on here, is setting the lash.... if you have to do this..... If you do, you are going to "zero" lash, and then some fraction of a turn on the adjusting nut. The engine really doesn't care if the lifter is pumped up or not. In time, it will reduce pressure to where it needs to be....equilibrium, if it is "over pumped" which it won't be if you prime the system after you set the lash... If I was installing new heads on an old short block, there is no way that I could (easily) "unfill" the lifters to make this scenario suggested possible!

The important thing here, is that once you do set your lash up, with new lifters, rebuild, etc, that you prime the system to displace air. Your lifters may not be totally pumped up yet, but they will do so very quickly upon start....as they now have at least some oil in them, vs nothing. Pumping the system up by hand with a speed handle is probably the oldest method of doing this. Usually a few turns the wrong direction will result in "bloop...bloop...bloop"noises in the pan....reversing the direction will soon result in resistance to spinning....and if you have your valve covers off, you will be able to see the oil come out of the rocker arm tops! This means that your lifters are at least partially full, the pushrods are full, and everything in the engine is gonna rock and roll that first couple of revolutions when it starts! Doing this will let you get on with other important things.....like fuel leaks, oil leaks....etc!


If you really are concerned about pumping up the lifters as much as you can before start, you can crank your engine by hand, to the three degree settings that you used when you set the valve lash......prime the system a few turns at each position and you should be golden......now to figure where to put the distributor rotor....hmm.....

Cheers! :)
Steve
 

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Lash-solid lifters
Preload-Hydraulic

OK, the only thing that I grossly disagree on here, is setting the lash.... if you have to do this..... If you do, you are going to "zero" lash, and then some fraction of a turn on the adjusting nut. The engine really doesn't care if the lifter is pumped up or not. In time, it will reduce pressure to where it needs to be....equilibrium, if it is "over pumped" which it won't be if you prime the system after you set the lash... If I was installing new heads on an old short block, there is no way that I could (easily) "unfill" the lifters to make this scenario suggested possible!

The important thing here, is that once you do set your lash up, with new lifters, rebuild, etc, that you prime the system to displace air. Your lifters may not be totally pumped up yet, but they will do so very quickly upon start....as they now have at least some oil in them, vs nothing. Pumping the system up by hand with a speed handle is probably the oldest method of doing this. Usually a few turns the wrong direction will result in "bloop...bloop...bloop"noises in the pan....reversing the direction will soon result in resistance to spinning....and if you have your valve covers off, you will be able to see the oil come out of the rocker arm tops! This means that your lifters are at least partially full, the pushrods are full, and everything in the engine is gonna rock and roll that first couple of revolutions when it starts! Doing this will let you get on with other important things.....like fuel leaks, oil leaks....etc!


If you really are concerned about pumping up the lifters as much as you can before start, you can crank your engine by hand, to the three degree settings that you used when you set the valve lash......prime the system a few turns at each position and you should be golden......now to figure where to put the distributor rotor....hmm.....

Cheers! :)
Steve
I have no tech concerning why you don't prelube hyd. lifters, I used to then read in literature packaged in a box of lifters NOT to prelube. I haven't prelubed new lifters in quite some time and can report no difference in the result.
Lifters that have not been prelubed, much easier to set the lifter preload.
 
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