How to Know the dry sump pump is still running

[Rob T]

Hi: I am looking for some innovative solutions. My dry sump pump is driven by a micro-groove v-belt. It is a scavenge only system that returns the oil through a cooler into a tank. The tank gravity feeds the OEM oil pump and filter system. If, at some point, the belt breaks or something happens to the pump, the engine will flood with oil and something bad will happen. Regular checking of the belt is key, but I am looking for warning of a catastrophic failure. An "idiot light" of sorts. I have a few ideas, but would like some thoughts on the details of their implementation.

1) Some sort of sensor that detects rotation of the pump drive pulley. This could be linked to an indicator light on the dash.
2) A pressure switch on the discharge side of the pump. This would have to be relatively low pressure, I think, but could be linked to the a light on the dash. This would indicate oil was returning from the pump to the tank.
3) A level switch in the tank - this could be done a number of ways...but would indicate all the oil was gone...

Any other ideas from this smart group. I get the concept that checking the checker makes things more complicated and, in general, simple is better. I am trying to evaluate if the "insurance" is worth it.

[mike223]

You could use a switch to detect the position of a belt tensioner (or similar device).

If the belt is not in place - the tensioner moves and turns on an idiot light.

[Gromit]

I would look to the automation/motion control industry. they make "rate" sensors You would want one that you can set the a minimum number of pulses per time and if the sensor is not getting those pulses it goes on. the sensor could be optical and look through holes in a pulley or say magnetic and have a magnet attached to the pulley to create the rate pulse I am thinking something like this... http://www.eaton.com/Eaton/ProductsS...dex.htm#tabs-2

I've never done it but figured if I had a dry sump this is what I would do. just my .02
Chris

[Wt4Go]

Rob T, just a thought, when I was in stock cars, we lost a few motors when the oil thickened and couldn't get through the cooler. Learned that we had to route the oil from the pump to the filters then the cooler.
Jim

[DSR-3]

Thru-beam or reflective optical sensor (Omron)?
*It always scared me to see the belt walking back and forth on the 1 pulley without flanges (2 different systems), but never had one come off!

[CdnCarNut]

You could use a camshaft sensor (or similar type) to monitor the pulley of the oil pump. As long as the pulley rotates, you should have pressure. Of course, a more direct indicator would be a pressure switch.

[Rob T]

Great input. Thanks. Keep them coming. Looks like a few good options.

[Bob_n_Cincy]

I was thinking about adding a GM oil level sensor to me dry Sump Tank. I haven't done it yet.
Bob


https://www.rockauto.com/en/moreinfo...431138&jsn=587

[DanielsDM]

I've been looking for an inexpensive level sensor that would work in a DS tank. I have my doubts about the reliability of a float switch since the flow through the tank will be high and could keep it from working correctly. Might get a false low level indication if the side ways flow pushes the float down.
Gill makes capacitive sensors used in high end racecars, with a high end price tag. https://www.gillsc.com/products/level-sensors/

Seems to me that the pressure transducer on the scavenge pump outlet is the low cost option most likely to work. I think I'll try that first, unless one of you guys does it first and it doesn't work.

[Bob_n_Cincy]

Seems to me that the pressure transducer on the scavenge pump outlet is the low cost option most likely to work. I think I'll try that first, unless one of you guys does it first and it doesn't work.

The output of the scavenge pump will be a very low pressure as it is open to the atmosphere through the breather tank.
Bob

[DanielsDM]

The pressure transducer would need to have a low enough range to differentiate the signal from the noise. Maybe 0-10 or 0-20 psi. I don’t have any data yet so won’t know what the value is until I try it.

A vacuum transducer in the crankcase could also be used to determine if the scavenge pump is running IF the pump flows enough to pull vacuum with the blow-by that happens when the engine is under boost.

[Sgt.Gator]

Another reason for a Vacuum/Boost sensor in the balance hose system if you are running a closed system. Besides telling you the pump is pulling a vacuum and how much, or failing to pull a vacuum and now you have positive pressure from blowby, it could also be set as an alarm to light a red light if it goes positive period. The only way it can go positive is either the pump is not pulling enough vacuum or is not working at all. Under either condition you'd want to alarm on it to avoid filling the engine with a DS tank full of oil or blowing out the seals from too much crankcase pressure.

On an open-vented system, you'd have to think of something else. In my LGT I had the DS tank mounted in the passenger seat area to the door cage bars. I always listened for the sound of the oil pulsating in the tank, "sloshing" sound. And in my STI the AN lines run thru the cockpit to the tank in the trunk. Again, I can hear the pulsating oil in the lines, and see the lines wiggle a bit from it. However I doubt I would notice in time to save things in a race if the sounds and wiggling stopped.

[DodgyTim]

A hall effect tachometer could give a rpm readout for about $20
https://www.amazon.com/DIGITEN-Digit.../dp/B00VKAT8A2
It doesn't give an idiot light output though

[RetroRacing]

It would just be way easier to do if one belt ran both the alternator and the DS pump.

[Bob_n_Cincy]

It would just be way easier to do if one belt ran both the alternator and the DS pump.

Implementing one belt would be easy like you said.
Bob
belts2.jpg

belts3.jpg

[RetroRacing]

Then you just need to run a wire from the alternator to one side of a dash light, and one from switch power to the other side of the light, light will come on when the engine is off or the alternator stops working (aka belt is off).