So I have been using simple head pressure to feed the MOP bypass, and it occurs to me maybe it would be a good idea to pressurize the auxiliary 2 stroke oil tank to help better simulate the circumstances the MOP would normally see under full oil system operating pressure.

Its been a while since I have played with the MOP, but IIRC the OMP should see no significant increase or change in oil flow rate from a higher pressure at the intake orifice assuming there is oil there for it to pull into the MOP...

But still, I am thinking that it might be a prudent solution to help mimic the conditions seen at the MOP in its originally designed form.


My reservoir tank, while substantial in volume, equipped with level sensor, and slosh resistant to air bubbles, is fairly low on the car, and does not supply a great deal of head pressure.

The setup I am using has not seemed to be an issue from everything I have checked.

So I am wondering what everyone else that is using a OMP with auxiliary tank has for a setup? Where, how high is the aux oil tank mounted and the plumbing employed in your OMP bypass setup?

And whether anyone has any opinions about pressurizing the aux oil tank with a small low Psi 12Vdc electric air source , and whether it would be a prudent addition considering the MOP and its original functionality?

 

I like the idea of inducing pressure into the tank, but let's be honest here, why waste money, time and increase weight to install a electric air source when you can just plumb charge air? Make sure the tank seals good and put a check valve in place so it has pressure over a long no boost drive, and does not need to be re-presurized every time you go into vacuum...



J.

 

We used to use charge air to activate and push the intercooler water spray cooling. I'd use a similar thing.

Car comes on boost, it needs the oil metering system to increase. So use the charge air to help increase it during that time?

 

Not sure of what bypass your are talking about. Here is how a stock OP works.


The stock OP/OMP system oil cavity is not under pressure.
Oil comes through around the shaft and that which makes it to the end and into the cavity fills it up through the rectangular opening to the left of the pump drive shaft.

Any excess then drains through the small hole on the left back into the oil pan.

The shaft drives the MOP pump and the internal flow rate valve is controlled by the ECU.

When using an external 2 cycle oil tank, one way is to use a separator plate between the housing and MOP so oil can not leak into the engine through the two holes.

Only then will there be light pressure do the oil tank being higher than the MOP.

 

My Aux tank is plumbed in this manor, and includes a 1 way check valve for replacement air.
I thought about using the charge air, but as you stated, when it is in vacuum, its not really accomplishing the task that was outlined above.

That being said, it seems like a easy no mess solution, just wanted to pursue something that was more full time duty cycle, if required at all ?!?

 

I don’t think pressurizing the OMP feed line will increase the amount of oil delivered based on how the OMP works in any measurable amount if I am not mistaken?

The issue is more about how well does the OMP pickup its “feed” oil under drastically lower pressures than the oiling system sees ~1ft of head pressure VS the stock oiling system, again assuming this is even true.

 

I am using the Rotary Aviation MOP bypass IIRC, it blocks off the stock feeder oiling system, but still passes the shaft drive from the engine to the stock OMP, as well as pipes in its own feeder line, but I am sure you probably know about that piece and its operation?


Its very possible Im misunderstand the way the feeder oil system works then, I would appreciate a more elaborated explanation if you would be so kind.

What is limiting the amount of oil pressure seen bleeding around the OMP drive shaft if I understand your explanation correctly?
Assuming you were to stop oil escaping back to the oil pan, what would you suppose the oil pressure seen there would be?
And would it then be practical to allow the engine side shaft cavity to then drain as was originally intended?

And if you had to make a supposition about the small amount of head pressure supplied by an auxiliary tank through a 1/4 line ~1ft height difference, would you be inclined to believe that alone would be sufficient to feed the OMP under normal/ or even severe conditions?

 

Keep it simple. pressurize it with an inline check valve. That is how I intend to do my setup... unless I can figure out a good way to have a high mounted tank.

 

Thats not a bad idea!
That would allow it to only be pressurized, and the check valve would suppress vacuum pulses, as well as keep residual pressure in the tank...



Where would you mount a tank at any higher point?
And at what capacity?

Mine is not very high, but I have ~2 gal capacity, and never have to think about it, until the alarm goes off which is nice!