Scary. So, there are times when the MOP is not feeding oil at all ?!?
There should be a continuous flow of oil.
For every two gallons of gas you use, at least an ounce of oil should pass through the MOP - not a 1/2 ounce of oil and a few cc's of air!

No wonder there are engine failures.

 

No, No - don't misunderstand me - the existing oil in the lines do not drain!

The air pockets that formed in my lines were only about 1/4-1/2 inch long in each line from the air pocket in the adapter.

I could see these small air pockets moving slowly as the oil is being used - all the while the engine is getting oil. The only time the engine is not getting oil is the last 1/4-1/2 inch of the air finally being pushed out at the end. You see, the air will not work it's way to the top, except with oil usage as the lines are too small and the oil too thick.

 

Ahh. OK.
On my current setup, I have little 1/2" bubbles in the clear lines that never move at all.
I'm hoping that replacing the MOP completely will solve this and the Sohn adapter is just an improvement, not a solution.
I have concluded that pre-mix is the only thing preserving my motor at this time.

 

You know, I was thinking about your situation the other day and was wondering if your OMP oil flow issue isn't the OMP, but maybe that your combustion chamber oil injectors (droppers-like) are just plain clogged up with carbon to the point of preventing any flow.

The OMP provides very little pressure, and with the carboning that is notorious in our motors, your injectors themselves may be just be clogged.

I suspect this is impossibly hard, but can the oil injectors be pulled and cleaned - or you could possibly run some really killer cleaner though it (double dose of BG44k?) to get all the carbon out of the combustion chambers and possibly clean them up enough to flow again?

 

When I do the Sohn installation, I'll pull the UIM and then oil squirters.
I wanted to check the check valves, anyway.

 

I really wonder whether the best thing for the rotary is just to premix and disconnect the OMP altogether

 

As noted elsewhere, the SpeedSource team does both, so I will go with them on that.

 

been done for quite a while on 7's that don't regularly replace engines.

 

are the bubbles at a high spot on the tubes? i'd think with the tiny flowrate the bubbles could find a high spot and could just sit there even when there is flow.

 

Not true. I've accidentally gone a full fuel tank in my RX-7 with no oil metering and no functioning OMP and the engine still works just fine. I'm not recommending that anyone do this though.

 

No, they were along its full length at uneven intervals.

When I installed my other pump and my Sohn adapter and started it up today, the bubbles all marched up the tube very slowly and were replaced completely by oil from the reservoir.
Now there are no bubbles at all and the tubes are clearly filled with oil (the refractiveness of the tubes is completely different now).

So, clearly, my other MOP was not functioning for whatever reason.

 

jeff, I just checked my omp tubes leading to the engine from the pump, and I can't see any bubbles in the lines at all.

 

Cool. That is how it should be.

 

Excellent!

You must have given it a good hard run to flow enough oil to clear the air pockets so quickly.

 

Oh yeah.

Well, I've used about 2 or 3 oz of oil in 100 miles, so I'm a happy camper!