Oil pump check valve?

I was wondering if the 6.2 engine oil pump has a check valve to prevent the oil in the galleys from draining back down into the oil pan. I’ve studied the oil routing through the engine but can’t seem to see one on the diagram. Does anyone have any knowledge regarding this?

I don't think so. I know if you ever let the oil pan drain plug out of one for an extended period of time and then fill it with oil and install a filter.
It will take a short time for the idiot light to go out on start up. So I would say no. I know why your asking. I would pull the wire from the injection pump and crank that new engine a few times before laying the coals to it. Good Luck.

Hey Rick - thanks for the reply. The reason I was asking about a check valve is because I am considering installing an aircraft pre-oiler pump to flood the bearing surfaces with engine oil prior to cranking. I have sourced the pre-oiler pump and worked out how to suck engine oil from the oil pan, but am not sure about where to return the pressurized oil back into the engine. If I install the return line at the rear of the block above the factory oil filter, and if the engine oil pump does not have a check valve, the pre-oiler pump would probably be circulating engine oil from the oil pan in a loop back to the oil pan. The main purpose of the pre-oiler pump is to flood the bearing surfaces, but without an internal check valve I don't think it wll work. If in fact there is no internal check valve, and if there is no way to install one, I may need to run the return line to the front of the engine and connect at the turbo oil port. Or simply abandon the idea all together. That is the decision I have to make.

Most automotive engines don't have a check valve in the oil circuit. If you pressurize the oil circuit the internal clearances in the oil pump will minimize oil backflow into the pan. There might be some but the majority of the flow will exit thru the bearing clearances. It will depend on the flow capacity of the pre oiler pump on how effective that will be.



Eddie

Just remember, volume over pressure. The pressure will kick in as long as you have enough volume, or when the motor starts. As long as there is a layer of oil, you will be fine.

Eddie & Gimp - Thanks for your replies. The whole reason for considering a pre-oiler pump is to add as much protection as possible to my P400 engine build. Everything I have read indicates that the majority of wear in an engine occurs at start-up before the bearing surfaces are flooded with engine oil. This is especially true for off-road excavating machinery in cold climates. Those engines are run long and hard and hot, and when shut down, the hot oil drains down into the pan. Then when they are cranked again the next sub-zero morning, it takes a few seconds for the oil pump to provide the thicker cold engine oil to the bearing surfaces. It is during these critical few seconds that the bearing surfaces are most at risk.

I began to think about a pre-oiler pump system when I added up all the $$$ I was investing in my P400 engine and 700R4 transmission. I researched it and discovered that pre-oilers are popular in the airline and areospace industries, where a bearing failure can be catastropic. I found an economical pre-oiler pump at Infinity Areospace http://infinityaerospace.com/product/other/pre-oiler-and-back-up-engine-oil-pump/ . The model I am considering is a GP302-24L which provides 2.1 gallons-per-minute at 30-40 psi at 24-volt. They offer the same pump in a 12-volt but I would want the 24-volt to reduce the amperage load and also so that the power would come from the back battery.

I had originally planned to pressurize the oil port above the oil cooler lines (see image below). This pressure point would be the closest to the pre-oiler pump and offer the least resistance to flow and pressure. Your thoughts?

For What it is Worth:

There are several oil pre-lube system on the market.

One is http://www.engineprelube.com

There are several others, run "prelube oil pump truck engines" in google you will see several.

Review there sites you will get several ideas how they are differently installed.

Regards

Joseph