Theoretical Valve Train Question ?

[salvageV6]

Well maybe not theoretical to some unlucky people. :frown:

Anyway in say ours, or any other hydraulic lifter application most likely, what would happen as in real world damage if the following happens:

Assume a stock system for now.

1. Lifter is fully pumped all the time due to stuck plunger or debris internally, therefore there is no hydraulic action and maximum valve pushrod action all the time on say 1 valve.

2. Lifter is fully defective with no pump up and no plunger action at all and valve is at minimum travel at the valve, and maximum travel internally into the lifter itself.

Any damage as a result of the lifter working, valve actuation, etc.?

Assume no initial debris from lifter parts or other junk in the motor, just from the working or not working of the valve train under these scenarios.

Mostly interested in any cam damage as opposed to how well the valve will work but of course all opinions are welcomed.

 

[turbodave231]

Oh, yeah, you will damage parts. Depending on how long the condition is left running.

Long term, you will beat up the tip of the valve, the rocker arm (both ends) pushrod, and the lifter we know is already toast. You will also damage the cam lobe.

All these pieces are supposed to be in contact 100% of the time in a hydraulic lifter engine. If they have lash (lots of lash in your scenario) the parts pound on each other and start to break down the surfaces.

If you have any parts like this, look at them closely under a low power microscope. Compare the damaged surface to a good one. You can see the difference.