The reason this modification was originally developed was to expedite oil drain back to the crankcase in road racing applications. AFAIK, Wheel to Wheel originally developed this, so Kurt could comment better than I.

 

So if your not road racing why would you take a chance modifying? I am planning my head/cam install and don't think I want to chance it especially since I only drag race!

 

I don't know of any 'risk' associated with this modification, so I don't see a negative aspect of it.

 

No risk associated that I have seen. The oil drains back faster to the pan. If you are running different rear gears or stall speeds the engine is operating in a different rpm band than the oiling system was designed for causing your oilflow inside the engine to go up, this mod raises the oilflow back to the pan.

Kurt

 

I didnt drill mine when i swapped heads. the trays are only going to hold so much oil holes or no holes... doesnt seem really needed? though im sure it wont hurt anything if you have trays out already, i just wouldnt be pulling the heads to do this.... with the harmonics of lifters moving up and down so fast i cant imagine oil staying in the cups at high rpm anyways..

 

i dont think oil on the cup is an issue, its the oil thats trapped in the actual tray.
oil on the cup is a good thing, or youd burn though pushrods and lifters.

 

oops when i said cups i meant the trays... lol


obviously the cups on the lifters themselves are always going to have oil because its being pumped into it.