Non-detergent oil in small engines

Just thinking out loud, can sludge basically act as grease?
So in practice in a low hp engine, does it matter if its oil or "grease" is in the bearing? As long as something oily/greasy is in there maybe it make little difference?
I just run T6 in everything because its what I have around and it might keep the old tiller going another decade....
 
I can understand the argument for non-detergent motor oils in un-filtered engines. Instead of wear particles being splashed/pumped around the engine... they should settle to bottom of pan. Whereas with filtered engines, you want those particles in suspension to be carried to the filter.

Isn't it the same principle with gear oils, non-detergent, particles settle to bottom near/onto magnetic plug (as with differentials)?

Now, whether is makes a difference or not in performance/life on "simple" OPE engines, I don't know. I know when we rebuilt our JD110's engine, the oil pan had a substantial layer of sludge/crud/etc... but the rest of the engine was fairly clean for being 35 years old.

That said, I only use detergent oils and don't even think about it... perhaps because that is all that's available readily locally. I've only seen GTX ND SAE30 and some "break-in" oils.
 
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bmwpowere36m3 is correct about the way it works. The old, low quality (SA) oil with no dispersants or detergents allow wear bits to drop to the bottom of the pan where they stay until the oil is changed ... with some staying until the engine is torn down.

This works, but it is old school and now there's a better way. That is: use a better oil, with additives that help prevent wear and sludge, keep the wear bits and byproducts of combustion swimming until the oil is drained ... and the engine stays cleaner longer.

I believe the detergents and dispersants in modern oils will attack the poured-lead bearings in antique engines. So, for restoration jobs, I believe you may have no choice.

Modern OPE engines ... and that's anything since WWII ... use better bearings and should use detergent oils.
 
Originally Posted By: Bror Jace
bmwpowere36m3 is correct about the way it works. The old, low quality (SA) oil with no dispersants or detergents allow wear bits to drop to the bottom of the pan where they stay until the oil is changed ... with some staying until the engine is torn down.

This works, but it is old school and now there's a better way. That is: use a better oil, with additives that help prevent wear and sludge, keep the wear bits and byproducts of combustion swimming until the oil is drained ... and the engine stays cleaner longer.

I believe the detergents and dispersants in modern oils will attack the poured-lead bearings in antique engines. So, for restoration jobs, I believe you may have no choice.

Modern OPE engines ... and that's anything since WWII ... use better bearings and should use detergent oils.


I have been using detergent oil in a 1939 Ford 9N tractor for thirty + years now after it has had non detergent oil, I have not had any issues w/ bearings or sludge plugging. It has been in the family since the early 60's, so I know its history.
 
I've torn down and rebuilt or repaired old V8 GM engines that have been run on both oils and usually found all gunked up. I think poor maintenance along with bad thermostats-short trips and running overly rich were the main problems. Often after cleanup-starting with a putty knife-they did ok.
 
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Isn't it the same principle with gear oils, non-detergent, particles settle to bottom near/onto magnetic plug (as with differentials)?


Gear oils have detergents and dispersants as well.
 
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I believe the detergents and dispersants in modern oils will attack the poured-lead bearings in antique engines.


Well, consider this.

Most SA ND oils are simply high sulfur content, minimally refined Group I oils with a small amount (3 ppm) of foam-inhibitor. During combustion, these elemental molecules mix with moisture to form sulfuric and nitric acids.

There are no dispersants, no detergents, no Anti-wear, no metal inhibitors, no VII's, no rust inhibitors, no added anti-oxidants.


In my view, SA ND oils are only good for coating rakes, plows, shovels, etc before storing them.

So how did these ancient machines survive?

They had large clearances (loosey-goosey), low compression ratios, large bearing areas, oversized components for the moderate loads, and were made of only cast iron and steel alloy components, and Lubricants had to be changed at very short intervals.
 
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well, a friend of mine says that his 6hp tecumseh snowblower requires 5w20 or 10w or Omega atf(5w20)....
What to tell this sort of guy? It seems like the craziest alernatives i heard of for quite a while
 
Personally I would always run detergent motor oils in air cooled or liquid cooled engines. There may have been a time when some detergent oils were not that good but even if that was true that was probably a long time ago.

Most manufacturers of small air cooled engines recommend at least SJ engine oils. And SJ engine oils are detergent oils.
 
Use whatever oil the small engine manufacturer recommends. My Honda recommends 10W-30 oil meeting at least SJ specifications, basically automotive oil.
 
Originally Posted By: Bror Jace
bmwpowere36m3 is correct about the way it works. The old, low quality (SA) oil with no dispersants or detergents allow wear bits to drop to the bottom of the pan where they stay until the oil is changed ... with some staying until the engine is torn down.

No not really the way it works, at least in the Briggs flat heads... The splash gear(slinger) sets in the low part of the sump that's actually lower than drain plug, but that's not the problem... Anything setting in that little pocket sump is going to be tossed around by the spinning slinger like ping pong balls in a hurricane... Any sediment is back in circulation within about five seconds...

My dad was preaching detergent oil as far back as I can remember(late '50s), he was born in 1927... I can say with 99.99% certainty the new B&S mower he bought in 1957 never saw anything but detergent oils(first house we lived in with a lawn)... I dunno what B&S was recommending back then, but by the early '60s was no doubt detergent oil...
 
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It probably would be hard to even find non-detergent motor oil nowadays. Such oil would probably be labelled SA or SB. I think SA had no additives at all.

I know that both Honda and Craftsman recommend at least SJ oil in the case of the Honda lawnmower and the Craftsman wheeled weed trimmer that has a B&S engine. And the oil that came with my Honda engine was Honda oil rated SN. The Craftsman weed trimmer came with Sears oil and I can't remember what the rating was on it. I used it just as a break in oil and I did not run it very long at all.

I don't think it makes a lot of sense to deliberately use poor quality motor oil in a new air cooled engine for a lawnmower or whatever. The oil is cheap compared to the lawnmower or weed trimmer or whatever you have. And today a person would probably have to go out of their way to even find such oil.

Honda recommends their oil which is a conventional motor oil and they say they test the engine with that oil. But synthetic can be used. I think B&S has actually gone to synthetic oil in some of their engines but in the case of my Craftsman weed trimmer they recommend 30 weight oil, except in cold temperatures. Honda basically recommends 10W30 but they allow 5W30 and straight 30 weight. But they seem to put a lot of emphasis on 10W30.

So I use 10W30 in the Honda and Super Tech 30 weight in the weed trimmer.
 
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Here you go, oil recommendation used by B&S from 1950-1959..

MS is Motor Severe or the best detergent grade of the time period... MS was used till 1967 when it became SC, wasn't long till SD oils replaced the earlier types and the rest is history(at least to SN)...

bs_engineoil01-2.jpg


From this site... http://classic-engines.com/engines-2/briggs-and-stratton-corporation/briggsstratton-7/
 
Originally Posted By: lars11
well, a friend of mine says that his 6hp tecumseh snowblower requires 5w20 or 10w or Omega atf(5w20)....
What to tell this sort of guy? It seems like the craziest alernatives i heard of for quite a while


I've seen quite a few older snow blower engines (mainly older Briggs engines) that recommended 5w20. I've never seen them recommend ATF though.
 
I have a 1980 B&S on a Snapper mower that recommends 5w-20 for winter, no doubt would be fine on 10w-30 and what I'd use..

bamps5w20_zps7c6914f4.jpg
 
I actually looked for some non-detergent 20W oil a while back. It was recommended for overhead fans. I could not find any.

The last time I remember seeing any non-detergent oil was several years ago when I was taking a walk. I noticed an empty quart oil container on the ground. It was a quart of oil (Silverstone, I think) that was rated either SA or SB. I think it was SB.

I don't know where a person would go to find non-detergent oil. Maybe some grocery store somewhere.

So if you did need non-detergent oil for some special reason (like for overhead fans) I have really no definite idea where to go look for it.

But for any engine, air-cooled or liquid-cooled, I would use detergent oil.
 
Originally Posted By: Mystic
I actually looked for some non-detergent 20W oil a while back. It was recommended for overhead fans. I could not find any.

The last time I remember seeing any non-detergent oil was several years ago when I was taking a walk. I noticed an empty quart oil container on the ground. It was a quart of oil (Silverstone, I think) that was rated either SA or SB. I think it was SB.

I don't know where a person would go to find non-detergent oil. Maybe some grocery store somewhere.

So if you did need non-detergent oil for some special reason (like for overhead fans) I have really no definite idea where to go look for it.

But for any engine, air-cooled or liquid-cooled, I would use detergent oil.
I've used Mobil One 10W 30 in two pumps in my hydronic heating system for about 35 years, though the pump labels say 30 weight non-detergent.
 
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