GEN IV Oil pressure question?

Ok, I have just rebuilt this L94, TSP Cam had to replace the oil pump when cold it takes a few seconds to build pressure, but goes to 50 Psi. When hot idles between 15 and 20 Psi. When I first start it cold the rockers click for about 3 seconds then quite down. I have installed a manual gauge and pressure is a little higher than the OEM gauge. Is this normal it seems the gauge is lazy but lazy on the Manual also, Now I'm pulling manual oil pressure from the drivers front port on the block. Does this seem normal or should I pull the trans or engine and go threw it to figure out what is going on. The second new pump is building more pressure when cold but I get idle at 700 rpm is between 15 and 20 Psi.

Just looking for a second opinion.

Thanks.

Try using a quality oil filter. Could be the drain back on the filter is bad, or, the oring is bad on the oil pickup tube to the oil pump.

All the stuff on this engine is brand new. The oil filter has been a Mobil 1 , AD delco filters and a K&N Filter no change with the filters. I have changed the oil filter 3 times changed oil from 5w-30 to 10w-40 and sae 30 HD the 30HD oil gives me a solid 40 psi cold idel, when hot 10 to psi at hot idle and a solid 20 - 30 psi driving 55 mph. I have pulled the pan and blocked off the Oil check valve in the pan. New High Vol High Pressure pump from GM performance. Only thing I can think is that the BarBell in the rear of the engine o-ring is cut or it is pushed out of the oil galley?
At this point I am pulling the engine out putting it on the stand and going threw it again. Little upset about this but we got to do what we half to, fixing anything wrong. Any Ideas?

Please let me know.

The cam retainer plate could have a bad seal too, if that is an issue oil pressure will be lower than usual or none at all.

I'm guessing if you plugged the valve in the oil pan, you've deleted DOD? Might be possible that the DOD/AFM towers on top need plugged with 1/4 rivets.

So first (speaking from experience on a 2x (10K motor) rebuilds) do not use a GM pump unless modified. They have lost may LS motors coming down of a full pull with the check valve stuck open and the resulting no oil pressure. Lost my first on a dyno run. Second, leaks around pickup tube are common. SacCityCorvette Billet Barbell, Front Oil Galley Plug, Pickup Tube Hold Down help. I also used Schumann Pro Series High Volume LS Oil Pump LS-PRO-XV which fixes the the check valve sticking issue. Make sure to align the pump correctly. Should make 15lb at 700 rpm idle and hits what ever you set the bypass to by 1500. 10-40 is too much for an LS. AMSoil DOMINATOR 10W-30 Racing Oil is as heavy as you want to go. So I am told by several LS engine builders. They prefer high quality 5-30 on a good build.


Good Luck.