How do you know or tell if Hydraulic Roller Lifters are or have floated?

[Qikbbstang]

Obviously a collection of shattered needle bearings in the bottom of the pan and it sounding like a real loose solid-cam is to late after the fact....................

[Barry_R]

I will use time on the dyno to give examples.  It's easier on dyno than it is in the car.  You are not fixated on little things - like guardrails or competitors, or traffic, or your girlfriend, etc.

You can hear it - the engines sound will get "raspy" or coarse right at the upper RPM ranges.  If you pull the rocker arms you will see a "butterfly", "bow tie", or "criss-cross" wear pattern on the valve tips.  The dyno sheet will show a sharp edged and significant drop in power/torque at high RPM instead of a smooth roll over.  If you have clear evidence you will sometimes see a corresponding +/-5psi drop in oil pressure as the parts separate.

In the car - if you are going to 6500 RPM with normal non-trick hydraulic roller parts you are floating the valves.  Pretty much guaranteed.

[blykins]

Barry gave the best clues.  The sound is probably the easiest to detect. 

If the lifters came apart every time you floated the valves, then there would be a lot of replaced lifters out there.  It just doesn't happen that way.  If a roller lifter couldn't handle a little lash, then a solid roller lifter wouldn't last 1 mile.     

[Qikbbstang]

Thank You Gentlemen:

 But Re: "If you have clear evidence you will sometimes see a corresponding +/-5psi drop in oil pressure as the parts separate."


Just checking because I have a sideoiler that is oiling my rocker shafts through the stands - not the pushrods, as numerous exotic rocker support systems do.


   I can see the both the top and bottom pushrod tips loosing oil if they were oiling but production FEs and my side-oiler feed oil through the stands.


 

[blykins]

Do you have a motive behind the questioning?

[Qikbbstang]

  Re: Do you have a motive behind the questioning?


 Nuck.......... Nuck........Nuck.... Why Certainly..............


My 427's finally getting close to together (custom pushrods this week) and to be dropped into my 4spd "Bullitt"  S-code
    I'd like to know what it takes to float the Hyd Rollers

[blykins]

What would it take?

1.  Too little spring pressure. 

2.  Too high rpm. 

3.  A very aggressive cam lobe shape.

4.  A combination of 2 of the above.