Years ago (~1979?) I had my 29U bearings rebabbitted by a local truck shop. I drove it very little for many years while I was in the Army. In 2003 the car threw a rod bearing. When I disassembled the engine, I discovered that the main bearings had been Groved wrong. Instead of channeling oil to the port in the crank shaft to lube the rod bearings, the groves in the main bearings where channeling the oil away from the port. It was a wonder the rods received any oil at all. Fortunately the mains were not damaged, and based on the advice of an experienced Babbitt shop in South Dakota ( unfortunately now closed) I added additional groves in the Babbitt to channel the oil properly. I only had to have that one rod bearing rebabbitted.
Also of note, check to see if the engine rebuilder left the small hole open in the rod bearings to allow oil to spray on the cylinder walls. You can see where the hole should be by looking at the outside of the rod bearing. Be sure Babbitt is not plugging the hole.
To prime my engines oil ports, I took a new plastic pressure spray tank, added a pressure gage, then installed a long clear plastic tube with a flare fitting. I removed the copper U shapped line from the engine oil pump, and attached the plastic hose to the engine oil port, then put about three quarts of oil in the plastic tank, pressurized it to about 25 lbs, and let er rip. That was plenty enough to force oil to all the lines and move the oil gage.
I next reinstalled the U shopped copper line to the oil pump and engine, then removed the oil pump cover and put into the pump a little Lucas oil, and reinstalled the pump.
Then I removed all four spark plugs, sqerted in a little oil for the cylinders, and turned over the engine with the starter ( ignition off) and spun the engine until pressure showed on the gage. That way I know the oil pump is primed. Then reinstall the plugs and start the engine.
Regarding the oil pressure, when adjusting the oil pressure relief valve after an oil pump or engine rebuild, it is best to start at a low psi and work upwards. First remove the pressure relief valve and be sure it is clean and the plunger moves freely in when pushed in. Then reinstall, leaving the cover off. Have a screw driver in hand, and have an assistant start the engine. Have the assistant call out the oil pressure to you while you adjust the pressure at idle to between 15-20 lbs. Then install the locking pin but leave the cover off for now. Next go for a drive and note the pressure at 30-40 mph. If it is below 30 psi, stop and turn the screw clockwise one half turn, insert the locking pin, and drive it some more at 30-40 mph. Repeat this until you get approx 30-40 psi at operating speed. Then reinsert the locking pin and cover on the pressure relief valve. (The book states 35-40 psi for operating pressure at normal driving speeds, but I run mine at 30-35). Several things to note, (1) the car can operate fine at only 20-25 psi at 30-45 mph. (2) Operating at pressures above 50+ psi can quickly damage your pump gear or worse, the cam gear ( I learned this by experience). If the pressure is above 40 psi, I recommend stopping immediately and adjusting the relief valve down (cunterclockwise). (3) lastly, at hot idle the oil pressure can drop as low as ~15 psi with no problems.
Also of note, check to see if the engine rebuilder left the small hole open in the rod bearings to allow oil to spray on the cylinder walls. You can see where the hole should be by looking at the outside of the rod bearing. Be sure Babbitt is not plugging the hole.
To prime my engines oil ports, I took a new plastic pressure spray tank, added a pressure gage, then installed a long clear plastic tube with a flare fitting. I removed the copper U shapped line from the engine oil pump, and attached the plastic hose to the engine oil port, then put about three quarts of oil in the plastic tank, pressurized it to about 25 lbs, and let er rip. That was plenty enough to force oil to all the lines and move the oil gage.
I next reinstalled the U shopped copper line to the oil pump and engine, then removed the oil pump cover and put into the pump a little Lucas oil, and reinstalled the pump.
Then I removed all four spark plugs, sqerted in a little oil for the cylinders, and turned over the engine with the starter ( ignition off) and spun the engine until pressure showed on the gage. That way I know the oil pump is primed. Then reinstall the plugs and start the engine.
Regarding the oil pressure, when adjusting the oil pressure relief valve after an oil pump or engine rebuild, it is best to start at a low psi and work upwards. First remove the pressure relief valve and be sure it is clean and the plunger moves freely in when pushed in. Then reinstall, leaving the cover off. Have a screw driver in hand, and have an assistant start the engine. Have the assistant call out the oil pressure to you while you adjust the pressure at idle to between 15-20 lbs. Then install the locking pin but leave the cover off for now. Next go for a drive and note the pressure at 30-40 mph. If it is below 30 psi, stop and turn the screw clockwise one half turn, insert the locking pin, and drive it some more at 30-40 mph. Repeat this until you get approx 30-40 psi at operating speed. Then reinsert the locking pin and cover on the pressure relief valve. (The book states 35-40 psi for operating pressure at normal driving speeds, but I run mine at 30-35). Several things to note, (1) the car can operate fine at only 20-25 psi at 30-45 mph. (2) Operating at pressures above 50+ psi can quickly damage your pump gear or worse, the cam gear ( I learned this by experience). If the pressure is above 40 psi, I recommend stopping immediately and adjusting the relief valve down (cunterclockwise). (3) lastly, at hot idle the oil pressure can drop as low as ~15 psi with no problems.