<VV> Lifter operation

[Bernie Livengood]

All hyd lifters work the same way!  There are (3)three
basic types.  Ball, disc, pin.  Back in the mid 1950's
I had the privlage of attending many technical
mechanic classes provided by the different
manufactures at the selected dealerships ie
Ford,GM,Chrysler,international,etc. with my father who
was a master auto mechanic with a GM dealership at the
time. One such class was on hyd lifters. GM was having
issues with hyd lifters in the early  V8 cadillacs,
oldsmobiles, Buicks and then just released Chevy SBC.
This class lasted about three hrs. It covered how the
lifters were design to function, how they worked, and
repair and overhaul of the lifers and what to lookout
for. The class was hands on! Yes, hyd lifer overhaul
was a routine thing back in the day. That was my
training on hyd lifers and all the years experience
since.  Bob Helt has described the workings of the hyd
lifer exactly right.  The proper method lubing and
pumping up (bleeding) is samerged in oil, a proper
actuating tool (pushrod)and the clearing of bubbles in
the oil surrounding the lifter. Another way is
intalled in the engine and pressurize the oil system
and slowly rotate the  engine until you see a study
rate of oil from the outer end of the pushrod.  There
you have it Gentlemen!  Make use of it and get on with
it!   Bernie 45+ yrs in aviation and automotive
maintenance
--- BobHelt at aol.com wrot.e: 

> In a message dated 7/20/2007 8:40:21 AM US Mountain
> Standard Time,  
> chsadek at comcast.net writes:
> 
> With all due respect, Bob, not true. That is not how
> current  hydraulic 
> lifters work.  I have OBSERVED the oil going to the 
> rockers, while priming.  You 
> need to disassemble a lifter and take a look  at how
> it meters oil. I have. 
> 
> Chuck S
> 
> And.....
>  
> 
> Smitty Says:  You are usually right about things Bob
> but not this  time.  
> Better go to the garage and take one apart yourself.
>  I don't  think anyone has 
> done more hours of research trying to find out how
> lifters  operate in the last 
> three years than I have.  I lost three sets of
> heads,  thousands of dollars, 
> and in effect, an engine because of the crappy SBC
> lifters  we are pretty much 
> forced to deal with.  I have torn down more lifters
> than  I would have 
> believed existed and they all have one thing in
> common.
>  
>  
>  
> Hi Guys,
> I can see that despite your many years of experience
> and disassembly of  many 
> lifters, you both still have an incomplete
> understanding of how a lifter  
> operates. So please allow me to enlighten you so you
> will know.
>  
> There are two oil compartments within the SBC or
> Corvair hydraulic lifters.  
> The upper one receives the flow of oil from the
> gallery and is filled with oil 
>  by the pump oil pressure. To get any oil into the
> lower compartment, oil 
> must be  forced past a check valve. This requires
> some oil pressure to accomplish 
> and  only occurs after the upper chamber is
> completely filled. This is done 
> by  use of a metering valve at the top of the upper
> compartment. When the  
> lifter is in operation (engine running) this
> metering valve is thrown by  inertia, 
> first, up against its upper seat (lifter moving
> down). This   blocks-off any 
> flow to the pushrods and rocker box allowing the oil
> pressure to  force oil 
> into the lower chamber. The point here is that
> unless this flow to the  pushrods 
> is blocked-off, the oil won't be forced into the
> lower compartment.  Then 
> when the lifter is moving up, the metering valve is
> moved off its upper  seat by 
> inertia and the oil flow is diverted to the pushrod
> instead of the lower  
> chamber. This lower chamber by the way is what fills
> with oil to raise the  
> internal piston to take up any slack in the valve
> train.
>  
> So if you both are correct and you have just
> installed a new lifter, or  
> lifters, without first filling them with oil, both
> chambers are basically empty  
> (maybe containing a little kerosene, and maybe not).
> So when you  finish engine 
> assembly and use your electric drill to run the oil
> pump, you want  the 
> metering valve to be pushed up against its upper
> seat so as to force oil  into the 
> lower chamber. However, as you both assert if THIS
> DOESN'T HAPPEN, then  oil 
> is now allowed to flow only into the upper chamber
> and from there to the  
> pushrods and rocker box, where you now observe it.
> The problem here is that if  the 
> metering valve is allowing oil to flow to the rocker
> box, then little if any  
> oil is actually being forced past the check walve
> and into the lower chamber, 
>  pumping the lifter up. No oil in the lowed chamber
> means the lifter is not  
> pumped up.
>  
> So AGAIN, I suggest that watching for oil dribbling
> out of the pushrods  
> after installing new lifters and running the oil
> pump with a drill motor is NOT  
> the best way of assuring yourself that the lifters
> are pumped up. You are only  
> seeing oil that has flowed into the upper chamber
> and then into the pushrods, 
>  and little if any going into the lower chamber. You
> certainly have no  way 
> of knowing how much oil is being diverted (if any)
> into the lower  chamber.
>  
> Regards,
> Bob Helt
> 
> 
> 
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