Controversial oil question

MolaKule

Staff member
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Iowegia - USA
Ive been doing research on 2 cycle oils and would like an expert opinion. This is a very controversial topic but I have yet to see any scientific explanation on it.

Looking at the additive package of a 2 cycle engine oil, it seems all it has is some calcium, and the rest of the additive package is slim to none.

Average 2 cycle engine oil additive package (Cheap Super Tech and expensive Amsoil):


Aside from issues such as falling out of suspension with oil, smoke and carbon blocking up exhausts, would a 4 cycle engine oil lubricate better than a 2 cycle oil in a 2 cycle engine?

How much of a difference would the additive package of the 4 cycle engine oil make in a 2 cycle engine? Would the zinc protect from wear better at the expense of running dirty?

How would multi weight oils such as 15W-40 react to being mixed with gasoline?

Assuming both the 2 cycle and 4 cycle oils have a high quality synthetic base oil, and the engine is jetted correctly to avoid excess carbon and exhaust spooge, would 4 cycle oil actually protect the engine better?

It seems like 2 cycle oils are made simply to burn clean and nothing more. I have always used synthetic 2 cycle oil in my engines but have been curious about this.

Which Amsoil 2-cycle oil, Saber or something else?
 
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2,343
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WA
Didn't know Amsoil and Red Line make 2-cycle oil. lol
Not sure why but it sounds funny.

I'm sure there is good market for it but 2-cycle oil was something I never cared or bothered to research until now ... Thanks to bitog. :)
I have a Stihl blower & trimmer.
 
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WA
Come to think of it and at the high level, wouldn't we be comparing apples to oranges. I mean one oil gets mixed in with the gas ... :unsure:

For some reason my brain stops me from wanting to compare the two oil when I hear the word "mix" (vs. No mix) ...
maybe if I get more educated about different oils, I can get past my mental block and want to compare the two! :alien:
 

oilresearchaccount

Thread starter
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18
That's a VOA of amsoil dominator @MolaKule

The comparison is a strange question yes, because the oils have different jobs. They have a completely different additive package, but when that's stripped away, what are the differences is what I want to know.

I'd also like to know the differences between cheap and higher end 2 cycle oils as well. Aside from the small amount of metallic additives what is different? Base oil quality? What non metallic additives are in a 2 cycle oil? What does it have that a 4 cycle oil will not have when we completely ignore the differences in metallic additives in both oils?

Are there differences in film strength between 2 cycle and 4 cycle oils?
 
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EU
You realize that most two-strokes don't have even a mild valvetrain? But can profit from "terpene compounds" for a "mandarin smell"?
 
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EU
So, what stressed areas in these engines would you focus on: What kind of behaviour on the oils' side are you actually referencing by "film strength"?

2T can be very different, can get quite far with just mineral oils + PIB, can have just some esters, can have polymer esters or else, can end up in the karting spheres of non streetable oils. For different reasons.
 
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Everson WA - Pacific NW USA
That's a VGO of amsoil dominator @MolaKule

The comparison is a strange question yes, because the oils have different jobs. They have a completely different additive package, but when that's stripped away, what are the differences is what I want to know.

I'd also like to know the differences between cheap and higher end 2 cycle oils as well. Aside from the small amount of metallic additives what is different? Base oil quality? What non metallic additives are in a 2 cycle oil? What does it have that a 4 cycle oil will not have when we completely ignore the differences in metallic additives in both oils?

Are there differences in film strength between 2 cycle and 4 cycle oils?

Here is my attempt at an answer but I also want to see @MolaKule answer as well, I certainly cannot list specific organic compounds and such.

Detergent/Dispersants, antiwear agents, biodegradability components and antioxidants. some of the higher quality 2T oils include a fuel stabilizer as well. Ashless/organic additives can be succinic ashless (no attached metals/semi-metals) dispersants, amines, polymer esters, perhaps fatty acids. some longer chains molecules that may not be in engine or gear oil. Anti-scuff, antiwear additives - high-molecular-weight components- additives that can survive the combustion process - in most cases you get what you pay for, the better more expensive oils will have better chemistry. On the other side of the balance, the oil needs to be clean burning - of course this is a dichotomy. For example a racing oil (Dominator) may have a different formulation (no fuel stabilizer, but higher temp non burning oils, maybe not so biodegradable) than a professional outdoor power equipment oil. There tends to be a bit more room to work depending on the usage - for deposits and smoke with racing oils vs. say a motor boat oil or equipment oil. But then again, the base oils will be different as well, for Example Saber is 14 [email protected]°C, v 7 for Dominator.
 
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78
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Illinois
About 50 years ago when I started mowing yards in the summers, I got my first brick lawnboy.

A brown c engine. It said mix SAE 30 SA or SB oil at 16 to one. So that is probably where it come from. The we had went to SE by then. Every other week I needed to drop the muffler and clean exhaust ports. Rings stuck at about 300. I was mowing about 20 hours a week.

After the first summer I got some of that fancy 2T oil and ran all summer with only 1 port cleaning at 24 to one. I had a quietflight too, great for early summer mowing. Then I got a green brick, much more power. Paid the unheard of price of 100 dollars with tax. Used lawnboy oil at 32 to one. It put me thru college probably close to 2500 hour on it. 2 sets of wheels, one set of rings and a piston and one slightly used carb from a run without oil mower. Not one single other part, not even points, I just filed them once. My sister inherited it, she managed to bend the crank and break the ears off the crankcase. She has a talent. Now I have my 82 F engine. Probably 4 electronic ignitions. It is still going with one overhaul, 2 sets of wheels (needs another set of the front wheels) and several primer bulbs. I hope it lasts until I have to go electric.

Rod
Your $100. green brick top sounds like my ‘75 7024. It now has 265 hours (hour meter) since it was rebuilt 4 years ago, The spark plug has yet to be removed. One of the questions I am trying to answer is how long can a Lawn Boy two cycle run before fouling a plug. I check the ports at 100 hour intervals, and so far have found very little (soft) carbon, and a few strokes with a round brush cleans them right up. The factory manuals from 45 years ago when this mower was made state plug cleaning every 25 hrs. and port cleaning every 50 hrs. What a difference oil makes. Although Lawn Boy had their own oil at the time it left the same hard carbon deposits as the SAE 30 W they were recommending only a few years earlier. Previously to this last rebuild I tried several different two cycle oils at different ratios and determined that the more oil you mix in the more carbon build up you get. Because of this and the fact that a Lawn Boy is a low RPM two cycle I have run only 50:1 mix of non synthetic in this rebuilt engine from the start. Four cycle motor oil would not be something I would use in a two cycle. When four cycle oil was being recommended in two cycles engines years ago that was the only oil available. Finally oil companies developed specific oil for two cycles and today it’s a whole different ball game. The difference in engine wear from using a four cycle oil versus a two cycle oil in a two cycle engine is a moot point since they both will provide lubrication equally well. The difference is what happened when the oil burns and what it leaves behind. Today’s two cycle oil burns cleaner, smokes less and leaves soft carbon deposits that are less likely to score pistons and seize rings, two of the major causes of two cycle engine failure.
 

oilresearchaccount

Thread starter
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18
The carbon issues will be especially bad in a low rpm 2 cycle, cooler temps especially will cause a lot more buildup, which is why outboards use ashless TCW3. Didnt lawnboy themselves also recommend TCW3 before? I have a couple lawnboys with the type F engine, great mowers. As for the SAE30, not sure if it will burn as clean as modern 4 cycle oil because non detergent also has nothing to help with carbon buildup, would probably have less coking and ash though.

As for why I'm interested in this topic: Curious about the differences in general, and I get virtually unlimited amounts of Duron Synthetic ultra high performance diesel engine oil, wondering if I can run that in some of my machines.
 
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Upper Midwest
As for why I'm interested in this topic: Curious about the differences in general, and I get virtually unlimited amounts of Duron Synthetic ultra high performance diesel engine oil, wondering if I can run that in some of my machines.
Virtually unlimited supply perhaps, but with a corresponding virtually unlimited demand? How much 2-cycle oil do you use in a month?
 

MolaKule

Staff member
Messages
21,950
Location
Iowegia - USA
That's a VOA of amsoil dominator @MolaKule

The comparison is a strange question yes, because the oils have different jobs. They have a completely different additive package, but when that's stripped away, what are the differences is what I want to know.

I'd also like to know the differences between cheap and higher end 2 cycle oils as well. Aside from the small amount of metallic additives what is different? Base oil quality? What non metallic additives are in a 2 cycle oil? What does it have that a 4 cycle oil will not have when we completely ignore the differences in metallic additives in both oils?

Are there differences in film strength between 2 cycle and 4 cycle oils?

While this may be your first set of analyses for 2C oil, there is really nothing controversial or strange about the analysis.

There are different strokes for different folks - No pun intended. There are various approaches to formulations for each type of application.

Hang on, my contractor is at the door!

OK, back, still dealing with the damage done by the Derecho.

In a two cycle oil you want the least amount of organo-metallic components in order to keep ash deposits to a minimum.

A one-pass lubricant must provide a lubricating oil film with a sufficient film thickness to keep parts wear at a minimum., yet the lubricant must not leave sticky deposits that will gum-up the rings and exhaust ports.

This requires a mix of base oils that will not only burn clean (since the lubricant is mixed in with the fuel), but also lubricate sufficiently. The base oils must be the purest of base oils, so in the beginning, the more highly refined Group I and Group II base oils were used.

Today, and in order to get the lean mixtures required for clean exhaust gases, a minimum of Group III through Group V base oils must be used.

Now to the additives. and as others have stated, a low-cost analysis will NOT tell you all of the chemical components included, only the basic organo-metallic components that can be detected.

The calcium and the magnesium combo is a mild friction reducer but primarily serves as a detergent that minimizes carbon deposits, but not all deposits. In modern 2C oils, this is up to the synthetic base oil mix, usually comprised of one of more ester base oils.

One anti-wear component seen is the low treatment level of ZDDP, the zinc and phosphorus. This is a special ZDDP ester with a low level of sulfur. A cold-start anti-friction/anti-wear additive containing a boron compound may be added.

The Tin is usually tin napthenate or Tin dithiocarbamate (DTC), another anti-friction component. Mobil uses a Titanium DTC for the same reason.

A high-flash solvent is incorporated to keep all of the components in solution and to make it miscible ("mixable") with the fuel. Now if higher ester levels are used, less of this solvent is needed.

Another anti-wear/anti-galling component, that also is used to thicken the film, is a polyisobutylene Group V base oil.

A small amount of a sodium compound is used to inhibit rust on the steel components. Not seen is something called a
dimercapto 1.3.4 thiadiazole compound, an anti-corrosion additive.

The last component that is used that does absolutely nothing is the Blue organic dye, except to make it purdy!

With respect to using motor (PCMO) oils in modern 2C engines, I wouldn't because the organo-metallic additive levels are too high (too much ash deposits, as on the valves and or ports and spark plugs), the base oils will tend to form sludgy deposits, and the PCMO does not really have a sufficient level of solvents to keep the rings and exhaust ports void of deposits.
 
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2,166
Location
missouri
The f engine will evenutally rust out the muffler. They are unabtainium. I am on my last one, it has patches. The carb can not tolerate alcohol. the electronic ingitions have been very unreliable. Primer bulb doe snot tolerate alcohol. I have 2 left. I think these factrors will limit the life of the engine much more than wear.

The bricks will wear out the throttle shaft in the carb and the carb aluminum body. I am pretty sure these are unobtainium now. i think a D engine brick will outlast the F. The D engine has a sleeve lower main. 50 to one scares me. 40 to one is OK long term. Many C engiens also have sleeve bearing in the big end of the rod. They cannot take 32 to one. This is why I no longer have the quietflight, a mower I liked as it was so quiet, the main noise was the blade hitting the grass..

Rod.
 

oilresearchaccount

Thread starter
Messages
18
For the muffler/carb I can make replacement muffler and get a different carb, I have access to metal shop/CNC as well. I mostly care about a good sleeve and needle bearings. Both CDIs have failed and are being replaced with aftermarkets.
 
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225
2 stroke oil have certain detergents that wont show up in oil analysis.

Its more of combustion related detergents
 
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Location
Marshfield , MA
The f engine will evenutally rust out the muffler. They are unabtainium. I am on my last one, it has patches. The carb can not tolerate alcohol. the electronic ingitions have been very unreliable. Primer bulb doe snot tolerate alcohol. I have 2 left. I think these factrors will limit the life of the engine much more than wear.

The bricks will wear out the throttle shaft in the carb and the carb aluminum body. I am pretty sure these are unobtainium now. i think a D engine brick will outlast the F. The D engine has a sleeve lower main. 50 to one scares me. 40 to one is OK long term. Many C engiens also have sleeve bearing in the big end of the rod. They cannot take 32 to one. This is why I no longer have the quietflight, a mower I liked as it was so quiet, the main noise was the blade hitting the grass..

Rod.

Rod, try these guys out for LB parts and general info. I have a very reliable but ugly 7023. It is a steel deck F pusher from '88 that I use as a trimmer. The starter went so I use a drill. The carb and the coil responded well to a good cleaning and I have a L21zp for parts
 
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