I recently rebuilt my 1973 F350 with an FE390 engine. After installing the engine in my truck and starting it the first time, I have absolutely no oil pressure. I checked the wiring and that's fine. I removed the oil filter and started the engine for a few seconds and absolutely no oil came out. When I rebuilt the engine, I put a new oil pump and pickup tube in it. Can anyone give me a suggestion as to what might be wrong with my oil control system. Any ideas would be helpful. Thank you!

 

Double check that the dizzy connected to the oil pump shaft.

I don't know if it's possible to miss the oil pump shaft when I stalling the dizzy but maybe????

​​​​​​You did install the shaft while installing the new oil pump correct??

Faulty oil pump (unlikely)

Is the pickup screen installed on the oil pump so that it's low enough to suck oil?.

How was the pickup attached to the pump. I guess it could have fallen off and in the bottom of the oil pan.

If you remove the dizzy you should be able to see the top of the oil pump shaft. With a old dizzy taken apart or I believe there is a tool you can drive the oil pump off a drill to build pressure. (I do this on builds before even attempting to start).

 

Adding to the list: how many quarts of oil did you put in this engine?

 

I put 5 quarts of 10-30 hight zinc break in oil

 

Should be enough but ... Although you will find some disagreement, most sources will say six quarts with the filter. Not everyone has confidence in all of the dip sticks one may find on a 390. What does your dip stick say? When to read the stick is also a subject of discussion. Some say that you need to let the engine rest a while after running before the dip stick will tell the truth but if your oil pressure is zero this is not a good idea.

 

Yet another suspect on a rebuilt FE has to do with what happened to the lifter valley plugs. They should be removed when the block is being cleaned and replaced afterwards. One of these plugs can only be seen by looking into the cavity where the distributor goes before installing the dizzy. If that plug was removed and not replaced, oil pressure would plummet. That one is easy to miss.

 

Rebuild, and two starts now with no oil pressure? I hope you were generous with the red prelube gelly. A good prelude with a drill definitely in order before #3.

At least disconnect the coil and spin it over looking at the gauge.

 

5 or 6 or 7 it wouldn't matter.

To have no oil at all at the adapter it has to be the pump, pump drive or suction.

 

I would highly recommend not attempting to start a brand new engine again with no oil pressure.
Pull the distributor and verify the oil pump drive shaft is in place, then spin the pump with a drill and see what you get.

 

Agreed, bearings might still be okay but the cam is most likely toast. it you have high pressure springs it is toast.

 

1 piece of wire from a wire brush can seize a oil pump. If you are lucky you may have sheared the roll pin on the distributor, slightly unluckier you may have twisted the oil pump shaft into something that looks like Licorish. Real unlucky you tear half the teeth off the cam and other half from distributor. Step one, pull distributor cap, see if rotor turns during cranking. Go from there.
If the roll pin is broke the timing will move quite a bit.

 

Since it will run that means the gears are intact, but the hex shaft could be gone.

 

For what it is worth column:
I am not a engine builder BUT the few I have built NEVER leave the engine stand until I see plenty of OP with the drill and see the oil.
then valve cover, s,

 

This was my thought, easy oversight I can see it happening. More so if it's not something you do every day.

OP has a lot of things to verify and get back to us on findings.

I am fearful for the cam shaft hopefully it's a roller.

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Agreed, I always put a mechanical gauge in place of the sending unit and run the pressure up with a drill. I leave it on until the break in is finished.

I used to rotate the crank 1/4 turn at a time to help get oil to the top end but I think it does more to wash cam lube off than anything else so I stopped that.

Roller cams are worth every penny I don't miss the drama.