Finally took off the heads of my old block, nothing unusual, no valve strikes (M6) for beating the hell for 80Kmi w/oem shifter, exept in the broken rod piston, well... again the usual some valve strikes in a daisy patern but not much.... lots and lots of carbon buildup thou

my question is that I understand Part of the concept of the Hyd lifters, they are some sort of a captive piston controlled by oil presurre and the area of the piston is just enough for NOT to lift the valve under relaxed state and oil pressure, and the compressing force is managed by a some sort of check valve.

how if the liftert floats the check valve opens to close the valve, or the lifter stays elongated beyond openning distance permanently.

if a lifter "collapses" it is correct that the seal created betwen the piston-cyl inside the lifter, or the check valve are compromised.

My lifters about ten of them are free moving (with my finger in the cup they move about 1/8" with little spring resistance, the rest are definetelly harder to move but non the less they move under finger pressure.

it is possible to clean the inside of the piston assembly in case of debris inside? taking the square snap "ring" (square) from the top of the lifter.

(see, less smily faces!)

 

Better replace them, I recommend Comp Cam 850-16 (about $199) at most sponsors

 

THE RIVER OF MONEY KEEPS FLOWING aaaaaarrrrrgggggggg!!!!!!!!!!!!!!

 

Haha! Sorry, but that was funny.

You know, the Comp 850s are cheaper than the stock lifters and far better.

 

I know im going to sound like a noob but even with all my engine knowledge and working on cars as a kid, Ive always wondered how in detail how the hydraulic lifters work and how the solid lifter differs. Ive checked out Crane's website but no one shows a breakdown of a hydraulic lifter and how it works in motor. I think I know at one moment, but then reading more stuff confuses me. Ive always thought the lifter was nothing but a roller attached to the lifter base and that raises and lowers the pushrod, but now hydraulic lifters im lost.

Dixit

 

I did not realize.... even controlling flow to the pushrods!!!! trhu the lifter piston!!!!

 

These are the parts in a hydraulic lifter. The plunger sits on a spring inside the lifter. The pushrod seat is installed above the plunger with a thin metal shield between it and the plunger. A snap ring, not shown, holds everything in place.

 

I just got a set of Crane 144530-16 (for 00-02 LS1s the part number for 97-99 is 10530-16) lifters from one of the sponsors for $198.xx shipped and from what I understand they are the best. They have antipump-up valves in them. My buddy who does all my work uses nothing else. PM me for which sponsor if you like.

Drew

 

Ok but when the cam lobe pushes the lifter up this moves the pushrod up and opens the valve. My main area I get lost on is how the hyraulic part works in this. If the cam lobe pushes the lifter up, what happenes internally in the lifter? To me it seems that the spring absorbs the lift and then when the spring bottom's out it then sends the lift to the pushrod. Or does the spring have alot of pressure that it never bottoms out, it just helps smooth the valvetrain.

To me having a solid lifter sounds better and less of a headache but dont get why hydraulic is the way to go for quiter valvetrain and supposedly less harsh on valvetrain and cam.

Thanks for taking the time to explain how it works.

Dixit

 

A solid or mechanical lifter is basically a solid chunk of metal (although the pushrod seat is a separate piece because it is made from a material that can endure the constant contact of the pushrod).
In a hydraulic lifter, the plunger can move up and down a small amount within the lifter.
Engine oil pressure forces the plunger upward, but forces from the valvespring, carried through the pushrod, force the plunger down.
As a result, the plunger absorbs shocks and eliminates clearance in the valvetrain.
With hydraulic lifters, valve lash is not necessary as long as lifter preload is adjusted properly.
Engine oil travels through mechanical lifters as well, but the lifter acts only as a conduit to carry oil to the pushrods, which transport the oil up to the rocker arms.

 

Okay that definetely made sense, just about what I thought how it works the whole time. Now if the hydraulic lifter moves a bit to absorb the shocks then techincally is it not screwing up the valve lift open/duration? I mean if it say absorbs .100" then say my lift was on the cam at that moment was .150", then it really only opened .050". I assume it pushes back once the oil pressure pushes the seat back to the top and gives back that say .100" it took, but doesnt this make a very inconsistent valvetrain then?

When we talk about preload I understand most of it there, but say you take a LS6 stock block, and I replace the stock lifters with CompCams oem replacement onces, how do I make sure the preload is identical? Plus how can I adjust it if the lifter is not adjustable and the ls6 rockers are not adjustable either?

Im learning a good bit here. Keep it coming Predator-Z

Dixit

 

When you use stock rockers, you adjust the preload with custom length pushrods.
Idealy they will all be different length, but going to the closest .05" is OK since the lifter absorbs the minute differences.
That is why adjustable rockers get you a more accurate preload and are usualy quieter if properly done.
A dial is used to measure preload or there is the old marking the p-rod method and measuring the drop difference.