Can Oil Be Sucked, or Must it be Pushed?

[Winston]

Kind of a complicated question actually.

At sea level there is 14.7 psi pushing on everything. If you can create an area with less than 14.7 psi, liquid will flow there.

A pump that creates a perfect vacuum can lift water approx. 32.2ft. Since oil is lighter than water, (SG=0.86, approx) you could lift it approx. 37.5 ft.

Does that help at all? What are you trying to do exactly?

 

[XS650]

Oil filtration on the "suction" side of hydrualic systems is coarse filtration designed to keep the big crud out of the pump. It doen't take much restriction to cause pump cavitation and screw-up oil flow.

The screen is all the filtration you should have there. You may have to drill into the cases to tap into the presurized oil circuit, bummer.

Wrong motorcycle, but this will give you a clue what you might be into.
http://www.xs650.net/oilc.htm

 

[mario]

Through a filter, that is.

I'm trying to design a better, add-on filtration system for an obscure Italian motorcycle, which sucks its oil through a screen and then through the pump and to the rest of the engine.

Are there any successful "suck-through" filtration systems, or is it just not possible?

Thanks!

 

[Pantera 74L]

Be very very carefull. The only suction side filter's that I know of are the screens on the oil pump pickup, auto trans filters and diesel fuel filters on Cummins.

It would be dangerous to put an oil filter on the suction side as you only have 14.7psi to move the oil through. Actually less than that as the pump will not pull a perfect vacuum. As the filter plugged the restriction goes up and may starve the pump. Not a good thing.

 

[mario]

OK. Thanks. Sounds like I'll need to re-think my approach to the problem.

 

[Gary Allan]

You may be able to install a bypass filter without taxing the main oil supply. The cheaper Amsoil setup has a 0.030 restrictor in the outlet. That, I think, should be a leak tolerable by any pressurized oil supply. That would afford you some filtration ..actually superior filtration. The only thing that you'll miss is random particles ..which is what you do already.

Can I assume that this engine has an oil pressure gauge?? If so, you can see if the bypass filter has any impact on pressure to the engine. It can be tapped to any pressure port.