UXV 500

[Lang01]

Hello all I'm new to the site.
I have a UXV 500 with little to no oil preasure.
We have just rebuilt engine which included crankshaft.
When engine is started it pushes a slight trickle out of the oil cooler hose and hardly enough to fill the oil filter.
We have checked and blown through all lines from the oil pump.
Checked oil pump to make sure within spec and direction.
Running 15w 40 oil
I'm thinkin oil preasure relief valve but looking for ideas possible checks.
TIA
Keith

[Lang01]

Also oil pickup screen

[CROSSBOLT]

These ball and roller bearing engines have a real low pressure system. It is more of a "flow" system but your description is alarming. I kind of wonder how it is possible ro reassemble wrong. I am NOT saying you did assemble wrong! About the only place the oil pumps to is the head. I will bet a gasket is missing a hole either at the head or cylinder base. Also look for a gasket that can be installed upside down/turned over.

[Lang01]

Thanku appreciate the feed back.
I have pulled all the top end down all looks good.

It looks like the pump pumps from the pump to the oil cooler through the filter up through the cylinder into the head which is all clear and I've blown through. It has nothing( (No oil) at the oil cooler and filter. No doubt something I have assembled wrong but I'm still thinkin maybe the preasure relief valve not seated or maybe not in however we didn't remove anything other then the crank in the crankcase but the case did go to the engine shop.

[CROSSBOLT]

Yes, check the relief. I lost all oil pressure in an aircraft engine because of small trash in the valve. This was after an overhaul, too.