I understand hydraulic lifters. I have questions on roller lifters ...

1) Does a roller lifter still get 'pumped up' with oil?

2) If not, does that mean that valve lash adjustment is more critical with roller lifters?

Hydraulic lifters get 'pumped up' with oil, and thus take up some of the 'slack' of the valve adjustment - in my mind, to a very small degree, this tells me that it's not a REAL technical issue to adjust valves when there are hydraulic lifters involved, since the oil 'pumping up' the lifter assists in making the total length needed (between rocker and cam lobe).

I also assume this is why for the last 18 gazillion years we have the "Great Turn Debate" - where some say 1/2 turn, some say 3/4 turn, some say 1 full turn ... after the valve stops ticking when adjusting on a running engine.

How does all this relate to roller lifters if they do not 'pump up' with oil?

 

On the inside, a hydraulic roller lifter looks just like a hydraulic flat tappet lifter.

Personally, when I tried adjusting my factory hydraulic roller lifters to 1/2 or 3/4 turn down with a ZZ4 cam, they would clatter. When I turned them a full turn down, they were nice and quiet. And, for what it's worth, the car ran quicker than it had before.

I would shift 1-2 at 6000 RPMs, and 2-3 at 5500 RPMs. It saw 6300 RPMs many times (usually on the freeway on-ramps when I was horsing around and not paying proper attention to the tach). Never complained. Haven't heard any complaints from the guy who bought the engine, either.

 

OK, cool. So, in essence, the roller lifters 'pump up' like a hydraulic lifter when the oil pressure is introduced, right?

 

No... a roller lifter can be a hydraulic lifter.

There are flat lifters and rollers, and there are hydraulic lifters and solids. That means you can have hydraulic flats, hydraulic solids, hydraulic rollers, and solid rollers.

 

Oh, yeah - I know there are solids as well. But I'm under the assumption here that most stock configurations use a hydraulic type, whether roller or flat. So, my curiosities are settled now, thanks guys!

 

On my recent 355 build with a Lunati 54779 cam, I adjusted mine to 1/2 turn past zero lash (static adjustment when building the engine) and they are perfectly quite. It really depends on the cam and that is why a lot of people recommend adjusting the valve lash while the engine is running.

 

My understanding is that as hydraulic lifters still have a maximum length they can produce you still have to adjust your valvetrain so that they don't need to reach this maximum length ... if not you will get clearance between rocker and valve stem thus causing noise (and damage ?)