oil pressure problem

[Mike Taylor 3601]

Your original problem sounded like oil getting away from pickup,Your next problem sounds familiar,you did'nt say what pump you put in when you changed,but I ran into problems w/ 3/4 pickup hex drive pumps that melling has,they idle good and drop pressure when rev'd.I sold several and everyone has been took back out& replaced for that reason,replaced with 5/8 pickup HV melling select pump and fixed it.
It acted like cavatation,but could'nt get to stop tried different pickups,clearances on pickup,overfill w/oil, just switched to 5/8 pickup pump and fixed everytime.
Years ago we used run 3/4 pickup bbc pumps in sbc without any problems,so I don't know why we could'nt get those pumps to work,I remember comparing pumps and could see no difference other than pickup diameter.
Mike Taylor 3601

[Adger Smith]

Take those nice screens out of the drain backs in the block as well as the vent pipes you screwed in the lifter valley. I bet it has a vac pump on it too. The oil rope that builds up around the rotating assy can keep the oil out of the sump. Get a good windage tray & pan combination on it that scrapes the oil back to the sump.
Those long stroke SBC's need the "right" pan and windage control.
Keep in mind your 434 has a lot more movement above the oil pickup than a 327 or 350.

[Reed Granrt]

Originally Posted by Adger Smith

Take those nice screens out of the drain backs in the block as well as the vent pipes you screwed in the lifter valley. I bet it has a vac pump on it too. The oil rope that builds up around the rotating assy can keep the oil out of the sump. Get a good windage tray & pan combination on it that scrapes the oil back to the sump.
Those long stroke SBC's need the "right" pan and windage control.
Keep in mind your 434 has a lot more movement above the oil pickup than a 327 or 350.

Yall better listen to Adger
I just got two 434 SBC off my dyno. Both wet sump, one with vacuum pump other without. Customer furnished both oil pan systems. Both blowed a hole in the oil as RPM went up. We dont run any screens as we have seen this problem a number of years ago. Ya got to get the oil off that rotating assembly. Spend time getting oil back too sump. Ya better look at windage, cause it is for real, both above the crank and below the crank.
reed

[79transam]

my pan has a scraper on it. its for my setup. i havnt tried a windage tray though

[Marine One]

Clarification - A loss of clamp load does not "spin bearings". When you see a spun bearing, you also see it extrude out from the sides. This is not because something was loose, but because everything was tight. In other words, the loose cap and spun bearing is a symptom of a larger problem.

A loss of clamp load will result in a bearing that retains its original width, but flattens out and has "bite / chomp" type witness marks. This is from the cyclic load on the rod journal...open, close, open, close...bite, chomp, bote, chomp....

[Ed Wright]

I can not imagine anybody putting a high volume oil pump in a SBC. Don't know why they even make them.

[Tony Curcio]

What happens if you put another half quart or more above " measured normal oil level"?