Insane or Sane: small oil circulating pump for gen

[henni]

So, a small project, the goal being to increase oil volume as an experiment on a generator. Side bonus would be to be able to rig up a filter for the circulated oil.

Steps:
1. Assume your standard 5kW to 7kW generator, for example Honda EM or EU series.
2. If dual 10mm drain plugs, use a Fumoto or Qwikvalve nipple extension part with a heat tolerant hose
3. Connect a 12v DC motor in-line, powered from the starter battery or it's own internal battery.

Something similar to this:
https://www.aliexpress.com/item/oil-pump...2693114001.html

Results hoped for:
1. The increased oil volume would provide some amount of cooling, perhaps an oil cooler could also be attached
2. The possibility of adding an oil filter would add service life extension to the unit.

Ok, now shoot me.

 

[jeepman3071]

It's a neat idea, but it adds complexity. A generator is something you usually start and walk away from until you are done with it or it runs out of fuel in the case of a power outage. Adding all this stuff will create more potential for leaks with little measurable gains.

I think your best bet with a generator is just to use a good oil, keep it full, and change it as necessary.

 

[SZR48207]

This seems simple enough to do on a weekend. Your biggest challenge will be to find components that can last.

 

[Sunnyinhollister]

If the generator see's 100's of hours a year, then why not. If it only see's a couple hours a year then to me it would be a waste.

 

[Donald]

Originally Posted By: henni
So, a small project, the goal being to increase oil volume as an experiment on a generator. Side bonus would be to be able to rig up a filter for the circulated oil.

Steps:
1. Assume your standard 5kW to 7kW generator, for example Honda EM or EU series.
2. If dual 10mm drain plugs, use a Fumoto or Qwikvalve nipple extension part with a heat tolerant hose
3. Connect a 12v DC motor in-line, powered from the starter battery or it's own internal battery.

Something similar to this:
https://www.aliexpress.com/item/oil-pump...2693114001.html

Results hoped for:
1. The increased oil volume would provide some amount of cooling, perhaps an oil cooler could also be attached
2. The possibility of adding an oil filter would add service life extension to the unit.

Ok, now shoot me.


Remember an engine with a filter has pressurized oil lubrication of bearings. No pressurized oil means you have splash lubrication. You add a filter to splash lubrication and I am not sure if buys you a whole lot.

My 8KW Winco propane generator has an oil filter. You do not need a huge generator to get an oil filter.

 

[Dyusik]

Now stick a remote filter mount with dual DBL7349 and never change oil again.

 

[EdwardC]

I would say that it's sane, but unnecessary. I feel that as it's already an air cooled engine, so the cooling is a side benefit, but unnecessary. And the service life with reasonable maintenance intervals is probably already probably long enough. However, I could see the value in having a larger sump and with the filter, being able to go much much longer between oil changes.

It seems like a a fun project. I'd be interested seeing how you get it so that the oil level stays approximately at the right level inside the sump. I can imagine a float, or maybe you could repurpose the low engine oil cutoff switch to sense the oil level. Or maybe switch to an oil squirting lubrication instead of splash? Please keep us updated if you end up doing this!

 

[dlundblad]

Get a power steering pump or an oil pump an rig a pulley and use a commercial electric motor.

Put the pump uphill from the generator so if it fails, the oil doesn't leave the sump.

 

[henni]

A 12v fuel pump works, already tested with 20W-50 cold oil, let it run recirculation mode (no heat) and pump runs fine.

A cutoff switch will also handle on-demand turn on/off where pump can be turned off without any impact to generator oil volume.

https://www.amazon.com/dp/B071ZSMWZ4

 

[jhellwig]

For fun it is sane. Practicality it is pointless as it will add no appreciable life to the unit.

 

[eljefino]

Just rig up something like an external transmission cooler. Model T's didn't have water pumps-- they just used a thermosiphon to circulate antifreeze through the radiator.

Your oil is thicker than antifreeze but you also have all kinds of time to have it make the circuit.

 

[Ducked]

Originally Posted By: eljefino
Just rig up something like an external transmission cooler. Model T's didn't have water pumps-- they just used a thermosiphon to circulate antifreeze through the radiator.

Your oil is thicker than antifreeze but you also have all kinds of time to have it make the circuit.


Not sure I'm understanding this, but if I am, I don't see how it could work.

AFAICT, for thermal circulation to work, the system would have to be full, with the engine acting as a heat source.

The engine wont run if its completely full of oil.

 

[SilverFusion2010]

If you’re just tinkering and don’t actually need the generator for anything critical , I’d say that’s sane. If you need the generator in question for serious work or backup power then I’d leave it alone and go find a junket to experiment on.

It’s an interesting experiment but as one poster above already stated, it’s not going to extend the service life of the engine. It might gain you longer intervals between changes.

 

[Linctex]

I did one once, on an irrigation engine that would run for days and days

All of the "accessories" MUST be located below the level of the engine.
Anything above will give false readings when checking oil flow.

Using existing plumbing ports is almost impractical. You would need to weld a flange port at the proper oil level to act as an overflow. It needs to be big enough to not be a restriction to outflow, or the engine will overfill. Another problem can be the crankcase breather, because positive or negative pressure affects the flow out of the overflow port, which really can't be vented to the atmosphere.

It is indeed fun to experiment with,
but quite impractical on any engine
you are not expecting to run for 5,000 plus hours.

 

[Cujet]

Originally Posted By: henni
So, a small project, the goal being to increase oil volume as an experiment on a generator. Side bonus would be to be able to rig up a filter for the circulated oil.



A number of us have used this idea on various generator engines (post hurricane) to extend the required 50 or 100 hour oil changes.

1) An engine with 2 drain plugs will circulate oil easily, without a pump, "if" the extra capacity is located below the engine, connected via 2 oil lines.
2) The oil tank below the engine must be completely sealed from leaks.
3) Extended oil change intervals is very viable with such a setup.
4) Particulates that tend to settle, will settle in the bottom of the new tank.
5) A restriction can limit the circulation rate and manage oil temps.

This is not unlike a larger oil pan on an automatic transmission or race engine.

In fact, Classic Air Cooled Volkwagen (Beetle and Bus) owners would often install any of a number of different aftermarket sumps to increase oil capacity and help manage oil temps. It bolted right on the bottom. Done correctly, they helped engine life in hot climates, and worked wonders on very highly modified engines.

Here is a large one that more than doubles oil capacity:

 

[Cujet]

Just thinking aloud here, an 11HP 5000W generator may hold 1.5 quarts. An additional 3 quarts would allow 300 hour oil changes vs 100 hour changes.

 

[henni]

Originally Posted By: Cujet
An engine with 2 drain plugs will circulate oil easily, without a pump, "if" the extra capacity is located below the engine, connected via 2 oil lines.


Can you elaborate, please ? If the 2 plugs are at equal level, how would the oil pull/push without some mechanical assistance ?

My original plan was to use one drain plug as the "suction" and use the oil check/refill plug port with a 90-degree adapter as "return". Have already located suitable part(s) to bolt it all together. A low speed 12v fuel pump would be acting as the oil pump and I have an on/off switch that allows the system to stop circulation but all lines stay connected. I can also reverse the suction and return direction. Using a separate standby battery, I can also recirculate oil when engine is off (just more insanity, but hey, it's a project...)

I had planned on connecting something akin to transmission cooler (old recycled parts), with about 1.5 qt capacity and had indeed planned on attaching it under the engine since I have plenty of space under the frame.

Remote oil filter kit
https://www.amazon.com/Derale-15728-Remote-Filter-Mount/dp/B004XONTPM

Oil filter
https://www.amazon.com/ACDelco-PF61E-Professional-Engine-Filter/dp/B00496KFTW

Misc parts
2 x 3/8" Barb 1/4" NPT Male fittings - http://amzn.to/2yaMWBD
2 x 3/8" Barb 1/2" NPT Male Fittings - http://amzn.to/2yaMWBD
4 1/2" Band Clamps 3 ft of 3/8" fuel line (or oil line) - http://amzn.to/2yvlYQY

 

[Ducked]

Originally Posted By: Cujet


1) An engine with 2 drain plugs will circulate oil easily, without a pump, "if" the extra capacity is located below the engine, connected via 2 oil lines.



That's interesting, and seems to have a lot going for it, notably simplicity. Hadn't heard of the Beetle supplementary sump. It appears to have a large port (which I'd guess mates with the Beetle oil strainer port) which should promote circulation and maybe allow manual cleaning.

However, I'd have thought the oil would tend to stratify in a two-port setup. The hotter oil in the original sump will tend to float on top, and sump turbulence might not be enough to promote mixing through relatively narrow drain plug ports.

You might be able to get around this using exhaust heat to create a thermocirculation, but that puts more heat into your oil, partly defeating the purpose.

 

[Cujet]

The crankshaft creates considerable force on the oil inside the crankcase. A sump, located below the engine will have no circulation issues as long as there is open flow path. A filter won't work.

Almost always, there are drain plugs 90 degrees to the crankshaft. One side has high impact pressure, one side does not.

The Lister diesel guys even make an internal scoop to direct flow.

Interestingly enough, the sump collects plenty of settled material.

 

[henni]

Originally Posted By: Cujet

Almost always, there are drain plugs 90 degrees to the crankshaft. One side has high impact pressure, one side does not.


Honda EM and EU have a single drain, thus, must use that as the outflow, into cooler, into remote oil filter, into 12v pump, into engine oil refill/check port located above the drain plug.