Should I have oil pressure when cranking engine?

[52FordF3]

I just dropped the engine back in the truck. Before I dropped the distributor in and do the wiring I just wanted to crank the engine over and see if I get oil out of the side of the engine where the oil filter feed line comes out. Nothing comes out. Shouldn't I see oil come out? Do I need to prime it somehow first. It is making me a little nervous. I do not want to crank it over too long and damage something. What am I missing here?

pics of engine in truck
http://www.jefftrumbull.com/?aid=5

[JSeery]

Yes you often have to prime them and yes you should be getting oil out of that port.

[petehoovie]

Did you pack the oil pump with Vaseline? This should be done to 'prime' the pump....

[Ross F-1]

How long did you crank it? Was this with the plugs out or in? I'd be inclined to just start with the filter connected and see if it builds pressure. Unless the oil pump is completely dry it should pick it up quickly with some running RPM.

[Jack E/NJ]

>>>Do I need to prime it somehow first. It is making me a little nervous.>>>

To make myself less nervous in such cases, I attach a big funnel to the sender or filter port. Then pour a quart or three of oil into the funnel and let it slowly percolate down thru whichever path(s) it wants to follow to reach the pan.

Jack E/NJ

[tubman]

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I have a thread on here I just resurrected where I had the same problem. Long story short, I installed a known good pump and pickup and got 10 lbs cranking with a 6 volt battery. I didn't go any further until I got pressure and I don't think you should either. One thing : do you have the proper restrictor fitting on the oil filter canister?

[52FordF3]

I was thinking of the pour oil back through the input of the oil filter line. I will try that next when I can. I do not have the oil filter canister on the block yet. I just wanted to see if oil came out from the block that goes to the canister. I did not pack the oil pump with vasoline. I never had any issue with "normal" blocks I built before. Just being extra careful since this is my first flathead.
Thanks for the feedback guys!!

[GB SISSON]

I screw a barbed fitting into the sender port and put a piece of tubing on it. The other end of the tubing is pressed over the snout on my goldenrod pump oil can. After this I have good oil pressure while cranking with the plugs out.

[G.M.]

Remove spark plugs, put a little MMO in all cylinders, put a rag over
the plug holes and spin the engine with 12 volts. The oil pressure
you see on a mechanical gauge will be the pressure driving at over
40 MPH. G.M.

[52FordF3]

Thanks everyone. I think the issue was the old oil gauge. I bought a new cheapie and it registers now. When cranking I got around 20psi. I proceeded to get it running and it maintains about 40 psi.

[tubman]

Originally Posted by G.M.

Remove spark plugs, put a little MMO in all cylinders, put a rag over
the plug holes and spin the engine with 12 volts. The oil pressure
you see on a mechanical gauge will be the pressure driving at over
40 MPH. G.M.

Not to be argumentative, but are you sure about this? The best I could get cranking the engine was a little over 10 lbs. When I finally started it, it had 40 lbs at idle.

[G.M.]

Originally Posted by tubman

Not to be argumentative, but are you sure about this? The best I could get cranking the engine was a little over 10 lbs. When I finally started it, it had 40 lbs at idle.

I'm positive about it, did it over 50 times. I do this with the intake
manifold off and can adjust the front bypass valve to get the pressure
I want at over 40 MPH. I check the oil pump for pressure before
installing and if it is adjustable set it higher than the front valve
so the front controls the pressure, G.M.

[G.M.]

Originally Posted by tubman

Not to be argumentative, but are you sure about this? The best I could get cranking the engine was a little over 10 lbs. When I finally started it, it had 40 lbs at idle.

I'm positive about it, did it over 50 times. I do this with the intake
manifold off and can adjust the front bypass valve to get the pressure
I want at over 40 MPH. I check the oil pump for pressure before
installing and if it is adjustable set it higher than the front valve
so the front controls the pressure. Were you cranking with the plugs
removed and 12 volts to a 6 volt starter?? G.M.

[12cliff23]

kind of along the same line, I took my oil filter and line off my 8ba for cleaning
and noticed the brass fitting near the top of the filter canister has a very small hole compared to the one on the bottom. does the size of the hole have anything to do with oil pressure?
thanks
cliff

[JSeery]

Yes and no, if the restrictor is removed it can lower the oil pressure going to the engine. But it is not there to regulate the oil pressure, it is there to restrict the amount of oil entering the filter.

[12cliff23]

thanks
cliff

[Bruce Lancaster]

My procedure is to put in the last two quarts of oil immediately before fire-up on a new engine. Simple rig, just a coffee can and hose with a 1/4 pipe fitting on hose to go into a rear port. The oil dribbles in high in the system in a few minutes. Doing it this way I see the gauge move on first turn and full pressure the instant the engine lights up.

[G.M.]

Originally Posted by JSeery

Yes and no, if the restrictor is removed it can lower the oil pressure going to the engine. But it is not there to regulate the oil pressure, it is there to restrict the amount of oil entering the filter.

There is another restrictor hole in the vertical outlet pipe in the filter.
The oil from the canister flows through this hole on the way back to
the pan. Over 30 years ago I drilled both restrictors open some for
better filtering but don't remember how much. If I recall .080 seems
to ring a bell and the hole in the return pipe was over .125.
After over 30 years the 39 has over 125,000 miles, oil pressure hot
at idle 15 to 20 and 45 plus at driving speeds. Used Castol 20/50
from start up. Recently switched to 20/40 Cummins Blue diesel oil
because of additives in this oil. G.M.

[52FordF3]

I have always used Rotella T in all my solid lifter engines. So would this Cummins Blue diesel oil be a better choice?

[G.M.]

Originally Posted by 52FordF3

I have always used Rotella T in all my solid lifter engines. So would this Cummins Blue diesel oil be a better choice?

I think Cummins Blue is better but only you can decide that. Open
the attachment in my last post, compare the additives in both oils
and the results of an expert oil engineer. I think any small advantage
to better lubricant over thousands of miles has to reduce wear. G.M.