I just could not bring myself to trust plastic/copper tubing (visions of no oil pressure, or hot oil spraying all over my carpet, etc.) when I installed a mechanical gauge, so I went with larger ID/braided line from Summit (?).

6 VOLTS/POS. GRD. NW INDIANA

I too have had a faulty check valve in an oil filter which would give a delay on getting a pressure reading.  This delay was noticed the next morning after the oil had been changed and that delay became a way of life until the next oil and filter change at which point the delay was eliminated.  Wasn’t too worried at the time as I had figured it was an oil filter drainback issue and this particular vehicle (’55 Customline) had both a light and gauge and both were indicating a delay in oil pressure upon startup and started with the oil change.  That was an AC filter that gave the trouble and I simply went to using Motorcraft oil filters exclusively on the Fords after that.

 

And I agree with John in that the oil line itself being full of oil may also be a contributor as cold oil will definitely not give an instantaneous result on the gauge.  On the race cars, I’ll typically use a larger oil line to the gauge for a more accurate response rather than using the 1/8” copper tubing.

Lorena, Texas (South of Waco)

fellas, I have a mechanical gauge. The line I have going to the gauge is copper, not plastic. I just cannot figure out why the oil pressure takes a while to read now, when before (the first 3-400 miles or so) it read instantly.

I think what I might do is tap into the oil galley with a mechanical gauge right on the block with a T fitting and see if that makes a difference... I have not noticed any peculiar sound(s) upon startup, and it does have excellent pressure throughout (according to the gauge).

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

I know this is obvious, but there will also be some "drain" back" while the engine is sitting. The looser the bearings get, the more oil drains from the bearings and gallerys. It will take a moment for the pump to fill everything back up when you start. If you really watch, it will seem like an hour and a half with no oil pressure.

Frank/Rebop

Bristol, In ( by Elkhart) 

Dan:

Do you have an electric or a mechanical gauge?  If it's mechanical, when you installed the tubing to it it was full of air.  Air moves readily through a small tube.  As the gauge cycled a few times, oil worked its way up the tube.  I don't know why, but it does.  Oil moves more slowly in a small tube than air.  Maybe it's only a gauge issue.

John

John - "The Hoosier Hurricane"

Eddie - that is one of the things that baffle me. Both oil filters that I put on are the same brand. I can try a motorcraft filter and see what happens. how long does that take...

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

Hey Dan;  had a problem with the filter not having a check valve to keep pressure on when the engine is off.  Put in a Ford motorsport filter and now have pressure right away.   Some filters do not have the check valve.  Maybe????   God Bless   Eddie

Eddie

Lake Forest, Ca. 92630

Got a situation on a fresh 292. The new oil pump (gear type) was installed when the motor was put in. 15w40 rotella oil (the old formula, with zinc). Break in has gone fine, and so did the first 500 miles or so. It seems to take 3-4 seconds to get oil pressure to my mechanical gauge I have under the dash (Sunpro, also new when I put the motor in). After that, oil pressure is fine, at idle, stop and go, WOT, cruise, hot motor--whatever. Just seems to take a few seconds to get a reading.

For the first 500 miles, I had oil pressure instantly when I turned the key. I did change the oil filter and oil (same weight/brand) after break in but still a problem. I do not think this is an oil filter deal. What about that pump? it is a Melling.

Is the oil draining back through the oil pump???

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com