2 stroke oil in diesel/biodiesel

[Emporator Member Find all posts View Profile Close Emporator]

Hello all!

I read on a website of a guy mixing 2 stroke oil in with diesel/biodiesel. It's meant to promote a quieter running engine as well as providing some other benefits. I was wondering - has anyone ever tried mixing 2 stroke oil in with their fuel?

[Guest Close David]

Re: 2 stroke oil in diesel/biodiesel

I mixed up a small batch for my generator engine with some Diesel when I first got it. I had read a lot of things about the modern diesel not being a very good lubricant so I mixed in some 2-stroke to aid the break in of the engine.
I only ran about 5L through it at 16:1 and then I got hold of some bio diesel so didn't bother with the 2-stroke any more.

I would say that there would be no real benifit in running 2-stroke in Bio or WVO as they will provide all the lubrication possible from the fuel itself. For those running dino, I do believe there may be some benifits in it.
Given the cost of 2-stroke oil though, I think a person looking for lubrication benifits would be a lot better off just running Bio or adding some Bio or WVO to their diesel fuel. Who would want to use that stinky, foul, dirty Diesel crap though?

Generally with 2-stroke oil, I completely avoid the lawnmower/ chainsaw type oil as it really is inferiour stuff. Not sure if they still do it now but the premix you used to get from the servo ( BP ZOOM and the like) was terrible crap full of ash and didn't do a lot for engine longevity. Anything designed for motorcycles or outboards is good to use with my own favourite being Castrol Super TT. This stuff works fantastically and dosen't cost a fortune like some of the synthetics.

In a diesel engine that will burn Straight Vegtable oil, I wouldn't think the 2-stroke you used would make much difference at all so the cheapest stuff may be the best.

Having run 2-stroke engines on Veg oil mix instead of 2 stroke oil, I can say while the veg will coke them up, it is certainly a good enough lubricant to prevent an engine siezing.
This being the case, I would suggest that there would be no appreciable benifit in adding 2-stroke to Bio or wvo ( or blends thereof) with diesel being the most likely candidate to benifit from it. How much you would have to add to make any possible benifit though would be the question.

[Emporator Member Find all posts View Profile Close Emporator]

Re: 2 stroke oil in diesel/biodiesel

I think you're probably right about using 2 stroke mix in regular diesel David. Biodiesel provides ample lubricity compared to petrol diesel so I guess there's not really a need to use anything else. Still, I'll give it a go when I get the Pug back!

[Guest Close Marc1]

Re: 2 stroke oil in diesel/biodiesel

Considering the question was "has anyone tried etc" not what is your opinion, I will answer that I do use pure synthetic 2 stroke oil mixed with acetone as an additive for petro diesel and have been doing so for a few years with good results.
The modern synthetic 2 stroke oils burn free of residue and can run a 2 stroke engine at 12000 revs with 1:100 oil to petrol ratio. In a diesel engine the desired result is to supplement the lack of lubricity of modern low sulfur diesel and would be completely unnecessary if used with conventional diesel, let alone biodiesel.
Considering that petrol engines use 2 stroke oil as upper cylinder lubricant in proportions that vary according to mood and weather conditions, I settled for 1:200 litres as a ball park figure since I have no way to test lubricity results.

If I had access to proper biodiesel, not V(ery)P(utrid) biodiesel, I wouldn't bother with adding 2 stroke oil. I agree it is not cheap.
PS
1:16 ? !!

[Guest Close David]

Re: 2 stroke oil in diesel/biodiesel

PS
1:16 ? !!

Hello Marc,

What I said was 16:1 which is a totally different thing to 1:16. What you are describing is 1 part of fuel to 16 parts of oil! No wonder you seem to be expressing some sort of ridicule at this ratio, you have it completely Ass about.

It is a common thing for people who are ignorant in the workings and tuning of performance 2 stroke engines to make the fundamental mistake of thinking that the less oil used in a 2 stroke the better, but people who are knowledgeable know a lot different.

I have had plenty of experience with racing 2-stroke engines in many different forms and have been lucky enough to learn from some recognised engine builders as well as having read much on the engine design.
Virtually all engine builders and tuners agree that richer oil ratios are far superiour to leaner ones and there have been many tests done that show the more oil you pour into a 2 stroke the better.... up to the point where it is dribbling out the pipe freely where you can back it off till it stops.

There are also many tests that have been done on many different bike and Kart engines that show richer oil ratios, to a point, also allow an engine to develop significantly more power through better ring and piston sealing.
You may have ( or not) noticed that I said I was using 16:1 oil ratio when breaking my engine in. Obviously this is a critical time for an engine when parts need to work in with one another and tolerances are tight and pressures on contact areas are high. I suspect in a diesel engine with much higher compression ratios as well as having addition mechanicals like valves, the need for good lubrication would be even more critical.
Unlike a 2-Stroke engine, it would be impossible to add too much oil to the fuel so again common sense would dictate that one erred on the side of caution and added a generous proportion of oil in the mix.

While your technical explaination of oil ratios varying " according to mood and weather conditions" is very amusing, unfortunately it is also totally asinine. Oil ratios are varied according to factors such as gearing, jetting, the design of the exhaust and it's powerband, the track, altitude, humidity, time spent on and off the throttle, the way the engine is ported, timing and a few other things you are obviously not aware of.

It seems rather comical that you admit you have no way of testing lubricity results yet you choose to scoff at an oil ratio that many 2-stroke experts would reccomend while you " settle on a ball park figure" that there would be no way it could be compared to any other application to show any benifit at all.

Out of interest, how does your engine run on 200 parts of 2-stroke oil to one part of diesel?? No argument, you would get plenty of lubrication out of that ratio and it certainly wouldn't be cheap as you say!
Perhaps you did actually mean 200:1 ( as it is properly written).

Was there anything more to your calculation of this ratio than the convienence of throwing a 1 liter bottle of oil into a 200L drum of fuel??

[Guest Close Marc1]

Re: 2 stroke oil in diesel/biodiesel

Ha ha, I knew you would bite.... wow so much verbosity!

So lets see:

What I said was 16:1 which is a totally different thing to 1:16. What you are describing is 1 part of fuel to 16 parts of oil! No wonder you seem to be expressing some sort of ridicule at this ratio, you have it completely Ass about.

Ratio is expressed as the relationship between two quantities, since I did not say 16oil to 1 of fuel, to express oil to fuel ratio or fuel to oil ratio is just as valid providing the person that reads it is a biped and not a quadruped.

Your subsequent boring and lengthy rant about how much you want to pass to know about 2 stroke racing engines,..."the more oil in fuel the better " ... (hu hu) is completely irrelevant.

My only mention of the small amount necessary to run a 2 stroke engine like a chainsaw for example, with synthetic oil, in a 1:100 ratio is to illustrate that only a fraction of good quality modern 2 stroke oil is needed to lubricate an engine at 12000 revs that relies ONLY on that small fraction of oil. And this is in working conditions day in day out not a burst in a 10 minutes race that will destroy the engine anyway.

The amount of same oil necessary to aid the injectors and pump must be clearly less considering the large amount of fuel and it's still considerable lubricity compared with petrol, plus the enormous difference in pressure, speed and subsequent friction between metal parts comparing a 2 stroke engine at 12000 revs with an injector and pump at 1 or 2000 lazy revs.

So yes my guess is that half what is recommended by the 1:100 2 stroke oil manufacturers required for a 2 stroke engine must be OK.

As for your choice of 16:1, you must have some ancient MacCulloch 250 tucked in your garage somewhere that reads 16:1 on the fuel cap, so you decided to use that ratio. Just for a laugh I may tell you that such ratio that was necessary in the fifties and sixties, was poison for the engine yet there was no way around it with the quality of mineral oil SAE 30 available in those days.
Today you can run your chainsaw marked 16:1 at the recommended ratio of modern oils. some are 32:1 some 50:1 some 100:1 depending exclusively from manufacturer and additives level. Can you run it at 16:1? sure if you enjoy scraping carbon and changing spark plugs and cleaning out mufflers.

In a diesel engine? I think you could run a diesel engine on pure (good quality) 2 stroke oil no problem. A bit expensive though. I wouldn't dare doing it with el cheapo no frill 2 stroke oil, the one that requires a ratio of 1(oil):16 (fuel) or even 1:25
Then again many truck drivers poor their sump oil stright into the fuel tank.

While your technical explaination of oil ratios varying " according to mood and weather conditions" is very amusing, unfortunately it is also totally asinine. Oil ratios are varied according to factors such as gearing, jetting, the design of the exhaust and it's powerband, the track, altitude, humidity, time spent on and off the throttle, the way the engine is ported, timing and a few other things you are obviously not aware of.

Well, perhaps I was not clear enough for you. I said that PETROL ENGINES use 2 stroke oil as UPPER CYLINDER LUBRICANT in different ratios chosen not too scientifically. I concede that for clarity I should have used the word 4 STROKE PETROL ENGINES, even when the term upper cylinder lubricant should give it away to anyone with a discerning acumen like yours.


As for the question posed, if anyone is still interested, I say if you use low sulfur diesel use half the manufacturer's recommended ratio of 2 stroke oil and you should be OK. Read the bottle, they are not all the same.

PS
It is a common thing for people who are ignorant in the workings and tuning of performance 2 stroke engines to make the fundamental mistake of thinking that the less oil used in a 2 stroke the better, but people who are knowledgeable know a lot different.

Does this sweeping statement include the oil manufacturers who recommend 1(oil) in 100 (fuel) ?
What about the one that say 1:50
1:32?
Dribbling exhaust is the only way to go?

[Guest Close David]

Re: 2 stroke oil in diesel/biodiesel

Thank you for your reply Marc.
If anyone was unsure as to if you actually had any idea what you were talking about before, they sure don't now!

[Guest Close Marc1]

Re: 2 stroke oil in diesel/biodiesel

I wonder what it is...my breath?
Yes it must be that for sure.

Thou shalt be both the plaintiff and the judge of thine own cause.
William Shakespeare

PS
Bankstown, Mercedes Benz...that explains some of it.

[Matt Senior Member Find all posts View Profile Close Matt]

Re: 2 stroke oil in diesel/biodiesel

Just to revive an old topic, speaking with my chemical engineer fuel industry mate about this, his comment was that it is good to stop gumming using bio. His comment was the detergents inhibit gumming a cause of varnishing in the engine parts. This was my issue after 150K km on B100, varnish in the injection pump so I am going to try this for a while, TT type 2 stroke was recommended as it had the correct type of detergents. In the same conversation was the fuel bug question, he knew it by name but was surprised to know it lives all the way through B100 not just at a water / fuel interface. Going to get some of that for prevention and maintenenace.