Since I'm using Harland Sharp rocker arms, I need these to be oil-through pushrods.
The “traditional” method for top end oiling with HS rockers is thru the head/shaft.
With the standard ball type adjuster, there is no way to get the oil from the pushrod into the rocker body.
In that scenario, pushrod oiling would be dead headed at the adjuster.
Ahh, so originally when I was buying these I called HS and specifically asked about what they post on their product page for these, that being:
Special Notes:
- Needle bearings allow for more oil flow to the rockers.
- Oil restrictors may be necessary to maintain oil pressure.
Their response was: the roller needle bearing setup opens up the passages and if you maintain the factory top-end oil feed, chances are that you might be dropping oil pressure and flooding the top end with too much oil. Basically uncontrolled oil leak!!
They suggested that to avoid this I could go down the path of switching to a pushrod feed and either completely blocking off the stock feed, or limitting it with a plug. I subsequently tapped the head oil feed to accept a plug, which I have drilled 1/16", thus giving me a 0.063" oil feed. I can of course open this up as necessary, or at the very least this gives me some control over how much factory oil should be fed to the rocker arm assembly.
But...that also means that the bulk of the rocker arm adjuster/pusrod oiling has to come from elsewhere, that of course being through direct pushrod oil feed.
