small engine bypass filtering.

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Hello There:
First time poster.... Long time reader here....

I a have a Kohler electric plant I want return to service that was manufactured in the 1960s without any oil filtration system. Its got a lot of hours on it and from the looks of things its been neglected. Slowly I have cleaned as much sludge out and done as much remedial service to it as I can to make it reliable again. I am sure its got many more years of reliable standby use life in it or I would not have bothered.

SO my question, on a small single cylinder machine with about an half gallon of oil capacity and no factory provisions for filtering what would you guys suggest I do? Cranking cold and once at running speed I get about 30 to 40 PSI of oil pressure, and the set runs pretty well. I have an old filter housing for a Detroit coolant filter that fits a small screw on automotive spin on filter I matched up. I considered putting a restriction in the line tapped off from near a port where there is an oil pressure gauge to reduce the through flow so I don't lower my oil pressure too much and dump the oil back to the sump.

It would be quick and simple and should provide some decent filtering. The problem I am trying to address is this old plant has an automatic start function and load sense controller. Its starts and runs only as long as it sees a load greater that 60watts. Years of service like this has left it dirty, so I do not want to aggressively clean it but I also don't want to let what ever dirt does loosen up with use float around and potentially cause more trouble.

For oil I use Rotella T 15W-40 in everything and I know this has excellent cleaning properties and its worked well for me over the years in all my small engines. I never leave the oil in to long because I have always believed once oil starts to look dirty in a small engine with no filtration system then it is dirty and shoudl be changed ( this is in the 25 to 75 hour range depending on conditions )

So what do you fellows think?
Thanks in advance
 
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What size engine? details? what oil requirements? what wattage generator? pictures!

Small engines, like my lawnmower, don't need filters. I simply drain/refill the oil as needed based on time or calendar.

Monitor oil temp or your unknown location for weather conditions, to determine if a 15w40 is even needed. No point in straining a motor with overly thick oil.

The issue with filtration depends on oil flow available. Do you want to take oil away from the engine that is needed for lubrication/cooling for filtration?
If you do install a filter, I'd recommend a Frantz filter with a small orifice, very small. Problem is that once it gets small, it might not flow enough to clean oil or the orifice might clog.
 

FireChicken

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Good point, but not exactly the advice I was expecting.

This generator is not portable, and parts are hard if not impossible to come by. So while I set it up ( and add things like a Murphy switch, over speed, over temp, and low fuel.... ). I intend to leave it set up in a shed, with a drum of fuel in a ready state to start and stop as required for as long as it has fuel when I am not home. I really thought it might be a good idea to add some bypass filtration.

Without getting too far in to the specifics this is a completely cast iron machine weighing 300 pounds. All its controls are electronically with no solid state parts, the ignition is shield like an airplane, it has no regulator ( saturated field type machine ), so there are a minimum of things that can go wrong. I'm not sure there is a justification for adding this feature other than it got dirty and sludged up from years of short duty cycle service. When it does warm up and run for an extended period I am concerned about things I can not clean or see inside doing more harm by circulating in the oil.

A further question asked what is it? and specific details:
Size 35 cubic inches, single cylinder 1800 rpm Kohler engine K331, 5:1 compression flat head with full pressure lubrication Sison electric choke and a Phelon shielded Magneto. The generator is 4000 watt 1800 rpm Saturated field armature type with the main exciter also doing double duty as the starter, a TI series EL-8 automatic controller .

I don't have any photos but this is a near identical 3.5RM51( remote start or manual rope ), mine is a 4AM21 ( automatic load sensing with rope, but I would be hard pressed to explain how that works since this has no hand crank selector switch, maybe a factory typo... )
 
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There is pressurized oil system and filtering. Two related but different things. With pressurized oil you and pushing oil into the bearing surfaces. Without its just a splash lubrication. Filtering would require some kind of oil pump to push the oil through the filter. Modern engines use the same oil pump to push the oil into bearing surfaces and through a filter.

Have you checked out the generator section? It may have brushes, a capacitor and other components. Often you need a 4 wire ohmmeter to check it out along with the spec of the generator (winding resistance). I bought a Winco propane generator that ran but did not produce electricity. After a lot of checking I ended up replacing the entire generator head.
 
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Oi filtration is a good thing, but you need to decide if the benefit is greater than the risk of ruining your machine due to home brew engineering.

If you decide to go ahead (which I'm not discouraging), I would just say to start with a small oil orifice (maybe 1/32"?) and see how it affects the oil pressure and also see if the return hose gets near the same temperature as the bottom of the crank case. You can increase the orifice size if the flow seems to be not enough to heat the filter up (which indicates flow).
 

4WD

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I’d do a cheap but fresh Dexos 5w30 with a small dose of BG109 … give that a half hour at no load … drain it and see what comes out … go from there …
 

FireChicken

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@ Donald:
This has full pressure lubrication, it is not a normal K series engine and it has between 30 and 40 PSI oil pressure as per the 60 year old gauge on the side ( same as in video ). It does not have any provision for an old filter, I have never seen a single cylinder K series that did, Some of the OTC kohlers had them some of the L600 and L645 had a filter system, but this ain't one of those......

The generator is good, the exciter cranks it, the charging system functions.
Properly cared for I am told these are 10,000 hour machines. How many does this one have left, I can't answer but I would like to do what ever I can to extend that into the future. This will serve out the rest of its life as a standby unit only used when the power goes out.

Because of the simple design and lack of electronics this is the kind of thing you can oil up, store high and dry, and not touch for extended periods of time. One little splash lubed set I have runs once a year or less ( its also a K series with the same basic design ). I drain the fuel spring and fall and it waits until needed. There is no field to flash nothing to be serviced or touched once its oil up and stored.
I might clean the com and slip rings every few years, check the points and run it for a while but that's it, nearly indefinite storage fogged in, oiled up and covered in plastic. When needed pull the plastic off, open the fuel, close the master switch and hit start. It comes to life in a cloud of blue storage oil and warms up. After the need is over a service, new oil, fogged in, fresh fuel with Stabil, master switch off, battery minder on, and back into suspended animation until needed again.

But the big one is a little different and I am am working through some new procedures before I put it in place to replace the little

Very little technical on this engine, I think its a pretty rare machine, its even hard to find plugs for it because they are a shielded military style like Jeep. The Electric end is pretty straight forward and its pretty much the same as any of the other Kohler sets like the L600 plants in stationary use.
I did find a manual and in it you can see some of the details of the lubrication system but there is no provision for a filter kit

Really the only other things I can add are on some of these K series engines Kohler said not to use Multi Viscosity oil because they tended to increase oil consumption and deposits in the combustion chamber, but I think that may have more to do with the qualities of the oil 50 years ago. The engines call for 30 summer 5w-30 winter... 40 for higher temperatures. I run 15w-40 in everything summer and 5w-30 in winter ( some stuff just gets 15w-40 and its kept above freezing in winter ). I never had any lubrication issues with K series engines and Onans doing this.

So what if I set up a needle valve on the outlet side of the oil filter housing to set it to meter the amount of oil through just a standard oil filter. I could adjust the flow so I don't lose more than a couple of PSI pressure. Or how much should I set it to?. Would a regular automotive filter clean the oil to any great extent at low flow rates? Are there small bypass filter kits made that might be better than improvising? Maybe I could use a relief valve that dumps to a low restriction oil filter set just a little under normal operating pressure to ensure the engine is never starved of oil?
I am fishing for ideas hear fellows, I hope I have provided enough information for you guys to make some suggestions.
 
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We have an old Allis Chalmers tractor at the farm that is pressurized lube but doesn't have a full flow oil filter. It just has a small spin on bypass filter. I guess a lot of engines were setup like that back in the day. Something like that would be ideal for your generator. You would just have to make sure you use a really small orifice to restrict oil flow as to not cause a drop in oil pressure to the engine.
 
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I have two Listeroid CS diesel generator setups. A single cylinder and a twin cylinder. On both, I used a oil line tapped off the oil gallery, a 0.032 orifice located in the fitting screwed into the gallery, and a Motorguard 0.5 micron "air" filter as an oil filter. The Listeroid's oil temperature is quite modest, and the commercially available Motorguard filter elements hold up very well. This setup does a great job keeping the oil clean.

It won't keep the oil from getting black, but it's obvious at a glance that the oil is not dirty. Drops of oil on paper are still amber colored, not tar colored.

I've used this setup for 15 years now without any issues what so ever.

EDIT: Here is a pic of my Listeroid twin's motorguard oil setup. You can see the oil line coming from the source, and going down under the filter. Then the return line discharges above a cam lobe, (one that is typically not well lubricated as it is in a dry bay) for additional lubrication. My point is that while a tiny amount of oil is being bypassed, it's return location benefits the engine's longevity greatly.

Lp6AC1y.jpg
 
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FireChicken

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I have two Listeroid CS diesel generator setups. A single cylinder and a twin cylinder. On both, I used a oil line tapped off the oil gallery, a 0.032 orifice located in the fitting screwed into the gallery, and a Motorguard 0.5 micron "air" filter as an oil filter. The Listeroid's oil temperature is quite modest, and the commercially available Motorguard filter elements hold up very well. This setup does a great job keeping the oil clean.

It won't keep the oil from getting black, but it's obvious at a glance that the oil is not dirty. Drops of oil on paper are still amber colored, not tar colored.

I've used this setup for 15 years now without any issues what so ever.

Sounds like exactly what I am searching for.
Do you have a part number for the filter?
 

FireChicken

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Gosh time flies. I seem to recall that was 05 or 06 when you built that. The paint job and detail just fantastic!

Thanks for the input, I am going to try that.
 
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Gosh time flies. I seem to recall that was 05 or 06 when you built that. The paint job and detail just fantastic!

Thanks for the input, I am going to try that.
You may want a restriction orifice smaller than 0.032 inch. That may depend on oil temperature and oil pump size and pressure. The 32 orifice flows oil slowly in my case (low oil temp and low oil pressure) . But quite rapidly when oil is very thin, under a lot of pressure and hot.

Also keep in mind that a very small orifice can clog. Might be a good idea to configure a small orifice in such a way to prevent a clog, an inlet screen or pre-filter (like a spin on) is one way.

Sorry for the grubby pictures. The engine has seen a lot of post-hurricane use. It needs cleaning and detailing.
 

FireChicken

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You may want a restriction orifice smaller than 0.032 inch. That may depend on oil temperature and oil pump size and pressure. The 32 orifice flows oil slowly in my case (low oil temp and low oil pressure) . But quite rapidly when oil is very thin, under a lot of pressure and hot.

Also keep in mind that a very small orifice can clog. Might be a good idea to configure a small orifice in such a way to prevent a clog, an inlet screen or pre-filter (like a spin on) is one way.

Sorry for the grubby pictures. The engine has seen a lot of post-hurricane use. It needs cleaning and detailing.

I have some small drill bits, but I might make up something with a needle valve to adjust the flow rate move up to that size in small increments.
Check your PMs I am sure we are previously acquainted.
 
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Besides an orifice, prioritize engine oil flow by adding 1-10psi check valve feeding the bypass filter. I call it orifice sizing insurance. For example:

Motorguard doesn't make bypass filters. Many mod the air filter for bypass filtration. No modding needed with Frantz. There was a seller modding and selling motorguards but isn't anymore.


Plenty of good bypass housing can be found at swap meets and ebay.

BTW, your bypass filter doesn't need to be bypass filtration media. You can remotely mount PH8a sized filter, add an orifice/checkvalve to it, and get pretty good filtration that is easy/cheap to replace/cut-open/inspect whenever you want. Should keep oil clean enough for usage without worrying about toilet paper media. So, the full slow media becomes a tolerable bypass filter. And, the typical 3/4-16 mounts can use smaller or bigger filters as needed... like 3600 or 3614 sized filters, for mounting clearance considerations.

The mod to send return oil where it is needed is A+ modding.

Be careful with mods. Since engine is a keeper, and you want to keep the oil clean, just remember that all your hoses/fittings/mounts... become points of failure.
 
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Motorguard doesn't make bypass filters. Many mod the air filter for bypass filtration.
I used the Motorguard M30. It's available for about $67 on amazon. I used it in unmodified form. However, as I mentioned, the oil pressure from my engine is very low and the temp is also low at about 160 degrees max. So the plastic center section of the filter element is unaffected. "IF" you were to use Scott TP, as a filter element, there are a few spacers and washers needed. I don't have the specs, but I'm fairly sure it's easy to do.

Here is one way to modify the unit for TP.

 
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I have some small drill bits, but I might make up something with a needle valve to adjust the flow rate move up to that size in small increments.
Check your PMs I am sure we are previously acquainted.

I know both of you guys.
The "world" of small-scale, efficient home power generating is a small one.

I bought two Metro 6-1 Listeroids in 2007 - - one for me, one for my friend.
Mine hasn't run in over 3 years now (I have just been so busy with other things).
 
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If you must use the factory Kohler supplied pump, then I would use a .020" or .025" copper MIG welder tip for my orifice. You could make it even smaller by adding a piece of steel guitar string ( .008", .011", etc etc. ).

Of course...., you could always use a car power steering pump (or very small hydraulic pump) that is belt driven and have a 100% full flow system drawing oil from the crankcase drain, filtering it through a Fram XG8A, and then returning to the crankcase (a non pressurized system).
 
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