Advanced Engineering Tech - Whats the difference with more or less lifter preload?

OK im running morrel lifters. Thinking specs are .030-.050 preload ?

Lets say engine is set at .025-.030 will it be pumping less oil to top of engine?

Whats the affect of have more preload or less preload on a lifter?

I think preload is less about oil pumping and more about keeping parts of the valvetrain in contact with each other. Too little preload and your pushrods will start bouncing off of your lifters, resulting in valve float or perhaps something worse.

Too much preload will not let the lifter fully pump up, and may damage the lifter, cam, or pushrods.

If I'm full of shit, someone please jump in here and correct me.

Preload is basically a happy medium.

You want to keep a constant pressure on the lifter, without bottoming it out. This takes up any lash in the valvetrain.

As long as the preload is within spec, it shouldn't affect oil flow to the top end of the engine.

Whats the affect of have more preload or less preload on a lifter?"Preload" is something I know next to nothing about. I wonder if some cam gurus can come in here and tell us idiots a little about it in general, etc...

Good info here:

http://www.hardcorels1.com/vbulletin/showthread.php?t=1815

http://www.hardcorels1.com/vbulletin/showthread.php?t=2938

Every engine builder has his own preference, but in my experience w/ hyd. rollers, slightly less pre-load = more usable rpm and louder valvetrain. More pre-load = less off-idle torque and 100 or more less rpm on the top-end. This would be agressive ramp-rate cams in the 230*-up area, and if u have a lot of overlap, looser helps the idle. You can definetly hear mine if that tells you anything about my thoughts.

Every engine builder has his own preference, but in my experience w/ hyd. rollers, slightly less pre-load = more usable rpm and louder valvetrain. More pre-load = less off-idle torque and 100 or more less rpm on the top-end. This would be agressive ramp-rate cams in the 230*-up area, and if u have a lot of overlap, looser helps the idle. You can definetly hear mine if that tells you anything about my thoughts.

Depends on Who's lifters also.

I think preload is less about oil pumping and more about keeping parts of the valvetrain in contact with each other. Too little preload and your pushrods will start bouncing off of your lifters, resulting in valve float or perhaps something worse.

Too much preload will not let the lifter fully pump up, and may damage the lifter, cam, or pushrods.

If I'm full of shit, someone please jump in here and correct me.

No,pretty much right on the money.