My take on the oiling system crossover tube for the small block
I have solid lifters, and I do not have a problem because of good lifter clearances and plugging the flow to the driver side. I did not change cam to bearing clearance, just checked it
"the other thread said the cam bearing clearance basically closes the oil feed holes up to the galley which effectively restricts them."
This statement was said by you and quoted by procharged on the first page of this thread.
You made this statement in another oiling thread.
Checking your cam bearing clearance and your lifter bore clearance to make sure they are correct is good engine building practice as you said, but all cam bearings and lifter bores have some leakage by design. Solid lifters do not require pressurized oil. It is a waste of pump volume that is better sent to the crank. Solid lifters will survive on splash oiling.
Cam bearings leak just like rod or main bearings. The cam only sees half the rpm of the crankshaft. Unless you are using some really monster springs, cam bearings are over oiled and the volume to them can be restricted to cut down on pump volume that again is better sent to the crank. That is the basis of all performance oiling improvements on a sbm.Even if your lifter clearances are within tolerance, they still have some leakage, if you cut the flow to the drivers side, you have cut 50% of the lifter leakage. That oil volume is now available to make good oil pressure and send that extra volume to your crank. In a general rebuild it is usually cost prohibitive to bush lifter bores. If the bores have some wear, they will leak even more to the point that oil pressure could be a problem even with all the cam bearings and bottom end bearings in tolerance.
With a high volume, higher pressure pump combined with excessive lifter leakage you can develop the galley excess velocity problem that is the reason for tubing the block or running a crossover line to fix.
There is no way that I know of to restrict the flow of oil going to the cam bearings other than an inline screw with a smaller size feed hole or drilling new smaller holes in the cam bearings.
You claimed that you did this by adjusting the cam bearing clearance,
and I was asking how you do this.
You dismissed the need to restrict volume to the cam bearings completely in the other thread. You followed Dick Landys oiling mods
By cutting the flow to the drivers side, which was good, but that mod was half the reason for your problem free build, not that you checked your lifter bore clearance. Imho