383 low oil pressure

[ZDECKICH]

Electric gauge? Wrong ohm sending unit? What's a mechanical gauge read?

As stated above the mechanical autometer gauge. "Mechanical gauge I hooked up shows hot idle its around 5 (on mechanical gauge) shows 0 on the dash gauge. driving shows 15-16 on mechanical gauge and 12-13ish on the dash gauge."

 

[rickseeman]

This is a tough one. I still don't know what to do next except to prime it with an electric drill. It has a new oil pump. It's full of oil. The psi should go to 70 real fast. If it doesn't, how does it "feel"? Does it feel like it's really pulling hard and pumping a lot of oil and a galley plug is missing or a lifter popped out? Or does it "feel" like it's freewheeling and sucking air? Pay attention to the "feel". You are the doctor on this. Is it pulling really hard or is it kinda freewheeling? That is what we need to know. I had a 68 Charger once. Beautiful lines.

 

[4speed68rt]

This is a tough one. I still don't know what to do next except to prime it with an electric drill. It has a new oil pump. It's full of oil. The psi should go to 70 real fast. If it doesn't, how does it "feel"? Does it feel like it's really pulling hard and pumping a lot of oil and a galley plug is missing or a lifter popped out? Or does it "feel" like it's freewheeling and sucking air? Pay attention to the "feel". You are the doctor on this. Is it pulling really hard or is it kinda freewheeling? That is what we need to know. I had a 68 Charger once. Beautiful lines.

Great idea rickseeman. Just to add to that. with a HV oil pump, it should try to twist the drill out of your hand, and make the drill strain.

 

[lewtot184]

As stated above the mechanical autometer gauge. "Mechanical gauge I hooked up shows hot idle its around 5 (on mechanical gauge) shows 0 on the dash gauge. driving shows 15-16 on mechanical gauge and 12-13ish on the dash gauge."

Start taking things apart starting on top. Definitely not right. Could be something as simple as bleeding through rocker shaft not installed properly. Bearing clearances, camshaft or rods/ mains, would have to be very bad for that kind of pressure loss.

 

[BSB67]

1) show us a picture or two of the mechanical and electric gauge hook- up to the block.

2) Remove all fittings attached to the block for both oil pressure gauges.

3) make sure the block passages are clear for both fittings.

4) make sure the fittings/reducers/pipe nipples and tubing are all clear.

 

[lewtot184]

I've been thinking of something that may seem radical but possible. Could a standard rod or main bearing have been used with a .010" crank? Engine would run but roughly, and oil pressure would be very poor.

 

[PRHeads]

I ran into that situation on a 350 SBC ages ago.
10/10 crank, std bearings.
Ran perfect, no noise at all.
Normal-ish oil pressure on cold start, very very low pressure when warm.

 

[Bird 426]

My money is on the front cam plug wasn't installed. Yes, it will still have some oil pressure. I left the back one out on the left rear of a small block, the one that's easy to miss because you don't see it. The engine ran, and didn't hurt anything, was very slow getting oil.to the top end. He's got take it apart and find out what's wrong. I know it, and so does the OP. Can only do so much arm chair quarterbacking.

 

[lewtot184]

And, what if the crank was ground and somebody really missed the number? Pipe plugs can be an issue, cracked pick-tube, etc, etc. Best thing is to take the engine out and do a thorough check.

 

[ZDECKICH]

Engine will come out for sure at the point. Im going to drive it for the next month, if it lets go it lets go. After the month it will just get rebuilt the correct way. Thank you all for the help. Ill let you know what we find once the motor comes out.