David Vizard. High Lift Low Duration ?

[Henrysnephew]

The lash factor in a solid roller's life is undeniable.  I've got a '70 Harley Sportster that I bought new.  They have four cams that utilize solid roller lifters.  Correct valve lash is set to ZERO with the engine cold - I think that's why it's still rollin' after 50 years.  Randy M

[Blueoval77]

You can't solve the issue.  Anytime you have something with lash and high spring pressure, it will fail eventually.
[/quote]

Oh boy , well "Eventually" is relative now isnt it ? 

[gt350hr]

   The roller cams we use aren't "mild" by any stretch of the imagination , which is why we need high spring pressures. I could see a tight lash , "soft lobe" combination "working" but wouldn't possibly make big power like a super fast lobe like we commonly use.
   Randy

[Barry_R]

   Solid roller lifters have ALWAYS been prone to failure because of one thing , valve lash. Pressure feeding helped and some feel the bronze busing is the answer. "I" like the tight lash concept to limit the pounding.

Anything with needle bearings HATE impact loads.  Load bearing area is limited to the number of rollers since they are all line contact by design.  Most roller bearing applications run at zero lash or with some amount of preload to prevent brinelling of the bearing race.  Everything we do on race roller stuff is to work around that limitation.  Spring pressure requirements are more about camshaft design and control.  Folks that have the finances to run and develop on a Spintron can sometimes get away with far lower spring pressures than would be expected - the rest of us use spring pressure as a way to get into a safe zone on things.