DIY: Oil System Priming Tank

[m sprank]

It can cause an air damn.  Blockage due to the inability of the pump to make enough pressure to "burp" the bubble.  Thats what the scare was about.  People filling the oil filter and then never building pressure while cranking. 

[Max Capacity]

Interesting,... I fill mine about half full. 

But it's not a fully filled, sealed system, so to speak. There is plenty of open space in the system for air to move around and vent out. 

I realize between the pump and filter it is, but once the oil leaves the filter, isn't it being pushed to the engine where it sprays around inside the valve covers and such ?

I recently changed the oil on my 86' F150 with an EFI 302 V8, 43,000 miles on the engine. The truck had sat for a few days before the oil change. I don't put oil in that new filter as it's on an angle on the block. When I started it afterward, there was a little knocking until pressure built a couple of seconds later.

 

[m sprank]

With the air bubble between the oil in the sump/pump and the oil in the filter the system is able to pressurize, but not enough to force the oil in the filter out. So the pressure sensor upstream of the filter never sees enough to turn the oil light off while cranking.  Have heard new engine istalls had the issue following instructions from IAG. 

i never tested personally. Maybe a half full filter does not cause an obstruction. My thought was always that when you perform an oil change there is plenty of residual oil to lubricate during cranking to build pressure. For a new build I trusted my assembly lube to do its job. 

Edited June 9, 2023 by m sprank

[Enlight]

Here's Flatiron's Tuning's video about the air sandwich problem. I think @Max Capacity's precaution would prevent this problem.

 

[Max Capacity]

That issue seems to be on a new engine. Which they filled the oil filter completely. No oil flow at starter cranking speed.

When I started the new short block for the first time back in May 2012, I just started the engine like I do every day. I don't recall if I did the half full oil filter for that or not. My pressure light went out in seconds, just like every time.

I wonder if those "pro's" would just start the new engine, like I assume the factory does, maybe they would not have an issue. I doubt the factory primes each engine before starting it.

I do recall, back in May 2012, I had the key on the "on" position a few times before the first start-up. When it came time to start it, I made sure, once again, the fuel pump primed, gauges sweep, then start. Engine cranked three times and was at idle, oil light went out in seconds.

I also recall back in 2005 or so with our Honda race motor, trying to get oil pressure at starter speed, that was the longest 30-40 seconds of my life. That was a 486whp 1.6L single cam.

[KZJonny]

7 hours ago, m sprank said:

For a new build I trusted my assembly lube to do its job. 

 

22 minutes ago, Max Capacity said:

I also recall back in 2005 or so with our Honda race motor, trying to get oil pressure at starter speed, that was the longest 30-40 seconds of my life. That was a 486whp 1.6L single cam.

Been there. I get being precious about a new assembly, and especially with all the time money and work that goes into it. But if the engine can't survive being cranked for a while, after having been treated with some assembly lube in critical spots along the way, then I think you've got bigger problems? I mean, 30s of cranking, at starter speed, lubricated by assembly lube before you get enough pressure to turn off the oil light (50psi?)

I really do want to hear your experience with the pressure sprayer method tho. I do suppose that the fewer seconds the engine turns withough lubricant the better!

[Max Capacity]

The pressure bottle method has been around here for years now. I have never used it.

[m sprank]

6 hours ago, Max Capacity said:

The pressure bottle method has been around here for years now. I have never used it.

Same. 

 

[Enlight]

Well I did my prime today and got oil coming out of the turbo feed and both AVCS solenoids.

^ Precious