Kink in oil pressure line? While doing the headers? Copper or nylon easy to damage

Part of the problem was a bad battery not spinning the engine as fast, oil pressure is good now with the new filter and new oil
I think might have had a stuck bypass? but we are all good now, just need to reset the valves. Hope this helps someone down the road

Want to update on this, still not happy with how long it takes to build pressure.
it takes over 30-40 seconds of cranking. It does build up but not like it use to.
So pulled the pan and took the pump out, opened the pump and it was clean inside
relief valve moves freely I can see oil up on the cam and pistons.
So I have pressure but why so long to build after no internal changes?
Thoughts and Thanks

Not sure what oil line you have to the gauge, but if its the small copper or nylon remove it and install the larger braided oil line. The gauge will respond much faster to cranking pressure and the blip of the throttle.

I won't EVER use the starter motor to build oil pressure, NEVER
That is a old SB Chevy SOP, think about how many RPM the motor is spinning over on the starter and then how many when running
Will the oil pump work better at 150 RPM or 600 RPM?
I also fill all my oil filters up completely (until they won't take any motor after soaking full many times ) with oil before mounting them on the motor, that way I don't have to worry about how long my motor will run with no oil pressure after changing the oil and filter

If you run the 1/8" plastic line, it is possible to restrict it by over tightening the compression fitting on either end. I once "dampened" an over active, jumpy gauge this way.Works but you have to sneak up on it.

How fast does it build if you just start it?

Hint....... I would stay away from cheap oil filters. Please use a wix racing oil filter.

The Wix racing oil filters bypass at least 20% more oil than their standard 51515 Ford, Mopar oil filters. I don't want trash being bypass into the motor
I use them,51515 filters now instead of the racing filters on everything I own except the race car that has a big remote mounted NASCAR type race filter

You can say whatever you want to say about any brands of oil filter or use whatever you want, but ...... use a filter that can handle the psi in a effective manner.

Have you split open a oil filter?
I have years ago(1973 or 1974) on the first Hemi stocker we where racing in NHRA stock, 50W Valvoline oil and 20F outside air temp breaking in the cam in the drive way at 2000 RPM, bang it split down the center, what a mess
As far as oil filters and bypassing, I like my motors to get clean oil, not with larger particle in it due to the filter bypassing 40% cold oil

When installing the
new hedders I had to raise the motor and looks like I dented the pan enough to have the pickup
make a witness mark on the bottom of the pan. Also had a thick layer of brown sludge where the pick
up sits (oil is Clean). Cleaned the pan and ready to put back together I hop it was just a combo of those 2.
No clue what the sludge was, not abrasive and no metal and yes I bent the pan back

How do you measure the bypass quantity?

Wix has stated that their race filters with internal bypass bypass 200 % more(40% vs,20% than the stock filters do, they have also stated that their stock bypass filter can bypass up to 20 % with cold oil at the lower air temps, below 40F.
No rumors or I think I heard kind of information from me!

Ok. You're not actually measuring, just using supplier literature. So the literature is saying that the valve is twice as big, so it can theoretically bypass twice as much. But in reality, it will only bypass the amount needed to control/balance the pressure differential dictated by the bypass relief. You will not actually know if, when, or how much oil is bypassed. Arguably, another good reason to not use a high volume oil pump and high viscosity oil.

I had a similar evasive pressure problem. Car would have pressure then lose it. Prime it with a drill and great pressure. Long story short it was a cracked pickup tube that finally broke off at the block (rb motor)

Same here except a hemi. Car would prime fine cold with a full pan of oil and be fine for quit awhile and hold 75psi until enough oil stayed in the top of the engine to get level below crack and would lose it's prime when the rpms were reduced.