External Oil Pump One Way Valve Mounting

After getting my engine on the run stand and letting it sit a few days between starts, it does seem that it takes 4-5 seconds before it picks up oil pressure so I decided to put in a check valve. Could you guys take a look and see if what I have mocked will work or do I need to take another approach. I thought I remember reading in my other post, that it was beneficial to have it laying horizontal, just worried about the two 90 degree bends.

I tried this way back but the one way valve I used must have been a restriction, I lost around 20 psi when priming with an electric drill. I removed it and never bothered trying anything else, just went to priming with a drill as part of the start procedure. Of course you may have a less restrictive valve but it's worth checking.
For info we are using a dual line, I only lose prime after 6 or so days, any time before that, the load is already on the drill. HTH's

With a check valve you should no longer have to worry about running the line over the pump. You could get away with a much shorter line running it down and under the pump. The check valve shouldn't care what angle its at.

Using the iron cover ... smart move !!!

I wonder if it is that pump combination with a stock cover causing your slow to get pressure

Why would that be the cause ?!?!?

Very good point on being able to able to use a shorter line. I actually have a shorter line with two 90 degree ends. I held it up against the pump and pan and I actually think it may work. It looks like it will have the check valve in a vertical position. If I can get the line to hug the block it should have enough room to where the crossmember isn’t an issue. I will probably try to mock it up tomorrow and post some pictures.

putting a loop in the hose fixes a prime problem

He doesn't have a prime problem. There is nothing abnormal from his video weeks ago. No engine picks up oil pressure with a tap of the key. Does the engine have oil pressure when running? yep. Is it normal yep. Good to go.

He'll probably cause a high rpm starvation problem, with all this bs and blow it up. Ain't no way I'm putting anything between my pump and its oil.

I have to agree with that.

My thoughts too. Maybe a dual line system would be fine, with double the volume capacity to start.

If this isn't a loop then please tell us what is !!

However with that said, even with a loop all the oil in the loop below that horizontal line will drain back into the pan - very easily and quickly when its hot. What little is left above the pump is all you have to prime with. Then that long loop as to fill up before you have continuous flow and pressure.

So while a loop is a good thing, you still want the feed line as short as possible. As for that check valve, its pretty fat - I doubt its very restrictive to normal flow.

I think what he meant by loop is a 360* loop. Then the oil will stay in the hose closer to the pump.

My point is all of this is nonsense. loops included, but they can't hurt. Stock internal set up has no loop and pump is in the same location.

Put an accumulator on it switch it on while you are cranking, problem solved. Doug

The problems come when the oil is thick, clearance in the pump may be too much, or the lines on the intake side are larger external, which provide a lot of dead air before oil is pulled into the pump gears . With a. Wide clearance like i found on my BRAND NEW milodon highvolume pump, even a high speed large drill had a very hard time pulling a prime. Once oul drains off the pump rotors too much leakage by the extra clearance caused my deal much grief. Two hours of hand sanding the aluminum pump body to reduce clearance may help. I sanded it down from .004 to .0017 clearance, which should help a great deal. I will reporrt back.

I have a hoop or loop, however everyone wants to word it on my dual external line pick with no issues. I also run a Accusump as a primer, or preluber.

I've used two in line oil filters in one of my old dual line Milidon external oil systems with no issue on lubrication on that motor I don't remember the micron rating of those filters, maybe 100+ micron
I had a small piece of the rear main seal holder pop off of it when I used to long of oil pan bolts and that small piece got suck up into the oil pump through the stock internal oil pickup and locked that pump up and broke the oil pump drive shaft off at the top of the oil pump drive rotor in the pump on the return road
Murphy loves messing with us stupid drag racers

I've seen pumps pick up chunks of block and never snap , and putting a filter in the suction line your crazy , What are you protecting with that? Lets see plug the filter destroy my whole engine? At least you stopped trash from getting in your pump.

Heck the factory will bypass the filter on the pressure side before hurting anything.

Actually those (Moroso maybe) inline AN filters where design for that application
I ended up breaking two oil pump drives on that deal before removing the pump and taking it apart One was a new Hi Po Mopar brand and the other was good use stock one, they both snap, twisted off, around the exact same place on the tips
I had to borrow the third one to run that race, I replace it later in that year at another division race

too bawlzy for me. Them engines can barley oil themselves in a perfect world, when you start to get past 6900-7000.

Im with B1MAX... these motors (B/RB/Hemi) have been raced for over 50 years with little to no modification to the external oiling set up but for some reason this one is special????? I think there is an issue that a check valve will not help. But thats my 40 yrs experience talking so I may be wrong
As a point of consideration...every fitting.connection will cause a disturbance in flow (reduced flow) and most if not all of us that have had check valves in any type of system have never seen them fail....as an example I had a check in the oil cooler line on my Bruno, it (the Bruno) got hot enough to melt the DOT spec vent hose laying on the case, why because a piece of debris got in the check and wouldn't let it open (the pressure side) want to bet whats going to happen on the suction side???

The reason I’m not using a filter on my 340, pump feeds straight up to galleys not through all those 90* bends and through a filter that restricts flow. If your pump stops working (0 pressure) let’s see you kill the engine before it blows. By the time it drops it’s already over and gone. Filters are for street cars.

Seems the least harm here can come from a check valve on the pressure side, not the vacuum side. Oil CANNOT leave the immersed suction side unless somehow air to replace the leaking oil can somehow gain entry, and a pressure side check would "check" both air and oil, regardless of loops, fittings, etc.
How/where you can place a check valve on the pressure side for a BBM is above my pay grade.

The closer the oil is to the pump ,the quicker it will prime. I had this problem using a Milodon aluminum pump with internal pick up. The pump needed a bigger O ring on the snout/drive end of the pump. It will suck air if that orific is not sealed.

Short line mock up.
While I am concerned about the check valve restriction, I have to keep reminding myself that on my “race” motor that I spin 7500 it uses a 3/8 internal pickup and the bearings always look good on it when i take it down. Even with the restrictions on a 12AN line it seems it has to be getting more oil than the internal 3/8 pickup. I was first concerned about the 120 degree fitting at the oil pump being a restriction but it does hold 80lbs at idle.

I like to think I'm familiar with every Milodon Mopar oil pump of the last 50 years but I've never seen one like that.

Me too, maybe

It is what you get when order a 21815 (the photo is old to new design)-it just has a Meiling pump cover on it. I called Milodon and they had no reservations with me using the stock style cover on it. It is the same with the their pump cover with the OEM style pump, I think they are designed to be used with OEM parts.

As has been mentioned, the one-way valve might be restrictive!!!

Guess you haven't looked in a Milodon catalog in the past ten years ... these aren't new !!

FWIW, now that I see the pump open I recall drain back issues being related to the design of Milodon's rotor design. If you were using a standard HV pump with a Milodon block plate for external pickup you would have no issues with drain back.

Interesting on what you say there, I have one of each type vanes and debating which would be better.

The rotor/vane issue goes so far back most are too old to remember it. But the issue is real.

Use one of the Peterson primer remote filter mounts. Spin it with a cordless till you have pressure and go. I would check both fitting hose joints on the suction side. If you're loosing prime you have an air leak period.

I don't like external filters but those things are so sexy.

Now if we could only get Peterson to incorporate a pre-screen, we would be all set.

Here's what I've run on my hemi for many years w/ no issues at all. Milodon pump w/ a stock cast iron pump cover. 7200+ rpm.

I've always used a 180 degree fitting on the top and never ever had a no prime issue.Now before I started using a 180 on the top nothing but problems.The 180 has to go over the top of the oil pump and against the block for it to work.

Who popped a wheelie and bashed his oil pan on the return to earth
I'm glad it didn't tear it open

Yep, I've done in it a few times now. The last time it did tear the pan open.
Put a nice Charlie's pan on it now, but the car may be retired for a while.

I had a titan pump on my aluminum block, never had this problem being discussed. I went to dry sump due to lack of ground clearance. Titan drawback is very expensive!

You are correct, I will probably step up to a Petersen multi stage dry sump system on my new race car for the local northwest no prep deal next year

Very cool! Didn’t know those existed. I googled them….SPENDY,!!!

Been on the market for 6? years, and yes $.

Well I think I’m moving into the no check valve camp. Just wanted to post for anyone else thinking of installing a check valve.

Started the car Saturday to head out to test and tune and was letting it warm up when the oil pressure light went off -20lbs. Giving it a tad of throttle and the gauge would fall back just a bit. Shut the car off and prepped the lift, got back in and when I started it. it took 4-5 seconds to build pressure and the oil pressure was back up to 60. Drained the oil, pulled the check valve and the plunger was gone. Pulled the pump and filter looking for the plunger but didn’t find anything. I cut the filter open, clean as a pin. Not sure where the plunger is, but it will likely go back together without a check valve.

I had it out the week before and it was holding 40 lbs at idle once the oil was hot (VR-1 20/50 Dino) and it held 80lbs down track at 7200, so no issues. Just really thankful it came apart idling in the shop and not at 7200.

I repeat.

I agree. I have never run a one way valve on any of my engines and I have never had any issues.

If I had a dry start issue that worried me enough to try and solve it……..I’d install an accusump.

But, nothing I’ve built to this point has needed one.

I was having that issue went with this simple loop and no problem with it picking up quickly. 440 Source cover on a Melling HV pump