Does the OMP on a S4 push the oil up the lines or does vaccuum suck it up..????

https://www.rx7club.com/1st-generation-specific-1979-1985-18/omp-question-427593/

 

This might help:

You guys are all wrong with how the omp works. First of all the omp is not on the high pressure side. It is above the oil pan in the front cover receiving drainage. Second, the omp is not a pump at all. It does no pumping. It is just a valve which opens to vary the amount of oil passing through it whether by electronic control as in '89 and up or mechanically before this point. The oil is actually pulled through the lines by the engine. As the engine turns, it puts a vacuum on the lines. The reason you still have vacuum lines on the oil injectors is because if you didn't, oil flow would be much faster through the lines. The oil injector vacuum lines actually tie in before the throttlebody. They only run to the manifold to get filtered air. Technically you could leave them unplugged but you risk them getting dirt inside them. The air passing through the vacuum lines from in front of the throttlebody allows some pressure leakage. The air moving past the oil lines however still exerts a small pull on the oil. If you were to block off these vacuum lines, the engine would just suck the oil through these like a straw at a much quicker pace. The reason that the rotary aviation reservoir adapter works without a pump is due to this suction. If you really want to get crazy, run the oil injector lines from the engine to a container of oil. It will still suck it through. This, incidentally enough, is how Racing Beat uses oil metering on the engine dynos. The engine is the pump.
It was a reply in this thread:
https://www.rx7club.com/showthread.p...7&page=1&pp=15

 

So in theory, when you are boosting, you are blowing bubbles in your oil!!!

Neeato!

 

First I want to get clear that I don't now or ever think that the omp lines were under great pressure.

What caught my eye in one of the above posts is where the word DRAINAGE was used to describe the source of the oil to the OMP.

If you have Acrobat Reader and go to the LUBRICATION section and blowup the schematic of the oil system, what I see is an oil passage from the front housing passing into the front cover thru an approx number 30size hole , then to the OMP itself.

Now that passage in the front housing is shared with the oil line that feeds my turbo. It ain't drainage as far as I understand the word drainage. It's approx 40-60psi depending on the engine speed.

And no, there isn't any vacuum on the line on top of the oil injectors.

And anyone who has owned/operated a 82 RX-7, carb version, KNOWS that the oil will travel up those oil lines without any vacuum whatsoever. On the first gen the lines terminate in the carb float bowl. Ain't no vacuum thar. The oil just ooches up the lines and dribbles in the float bowls and or the side of the carb if the lines are loose.

 

It didnt pass the sanity check for me either. Maybe I sould have finished the sentence with the patented -humor-