Okay guys, i have searched through tons of oil pressure forums on here and havent found my answer. so i have a 350 that was just rebuilt. i have low to no oul pressure unless its cold and it shows 20-25 psi. but when it warms up some it shows like 2 maybe none pressure. i got a new gauge and its not the gauge. also at higher rpms like before it shifts into 2nd theres a sorta loud rattle. so i was wondering why i dont have much pressure and if the rocker arms wernt tighten properly if they could be loose? i did not recheck them after the new break. and maybe a clogged pickup screen cause low pressure?

everything is new in this engine besides the crank,block and the actuall heads and rocker arms.
New valves, springs pushrods lifters,all bearings new oil pump,new noise geardrive , new lunati cam 284dur.458lift and new valve springs 0.550 in. maximum lift. installed at 1.750 in. and the pushrods are standard length
im using 5w30 and added and extra quart on 20w50 because i didnt think the HV oilpump was not getting enough oil because it was sucking so much and also thought the oil was tooo thin?

let me know if i missed something

 

No larger capacity oil pan?
You replaced the oil gauge, is it mechanical or electric? If electric, what about the pressure switch/sending unit being bad?
Did you braze the oil pump pickup to the pump housing? They can fall off if not.
Have you tried running the engine with the valve covers off to see if you are in fact getting pressure or not?
With zero pressure or close to it, the heads should be running darn near dry.

 

well we primed it on the stand and it had TONS of oil all over everything with the valve covers off so i know it gets oil. stock pan, and i just had to redo the 2 piece rear main because the one i got was **** and go a better one. so the pickup was on when i put the pan back on. and i replaced the mechanical one twice. thge oil gallery plugs are in foresure because i replaced them with new ones and i know there tight.

 

A few more ideas....
1) Your new oil pump could be defective.
2) The bypass valve (in the oil filter housing) could be stuck open.
3) You're using a Fram (orange) oil filter.
4) You have a kink or obstruction in your oil gauge tube.

 

that is what we were thinking is its a defective summit POS pump. how do u check the bypass valve? and nahh were using a microgaurd and just got a new gauge/tube.

 

Remove the oil filter, and look at the relief valve hole that's next to the oil filter fitting. Make sure no crud got stuck between the valve and housing. I would also try a different better name brand oil filter, just in case that one isn't flowing well. I like using the AC Delco/STP filter, but everybody has their favorites.

 

Did you put new cam bearings in? I have seen plenty of engines with bad cam bearing that loose oil pressure when hot. Your rattle is prob the lifters pumping down. I like melling pumps, and I pound the pickup in with a small tack

 

Update: so pulled the pan again and replaced it with a new melling std volume std pressure pump and new pickup tube. No change. Turned the oil filter "bracket" around got like 15 psi then drops to like none. So i pulled one of the valve covers off, started it up, not getting a single ounce of oil up through the heads at all. so what im turning to at this final point is bearing clearances. i swear ive checked like everything else besides plastigaging the bearings.

 

Alrighty then, who rebuilt the engine? Is it possible there was an oversight, and the crank journals were ground, but you don't have undersized bearings? I guess hindsight is 20-20, but while the pan was off would have been a handy time to check the crank with a micrometer to be sure.

 

ALLWAYS Plastiguage or mic crank rods and bearings before final assembly! also NEW CAM BEARINGS FOR A NEW CAM! dont do these things and oil pressure ALLWAYS suffers. Id pull that engine and check everything! its bleeding internally for sure