2 stroke oil to fuel ratio

[Lasse]

A small test begins with a different fuel than usual. High quality alkylate petrol (non ethanol + high quality low smoke 2t racing oil mix vs normal pump gas + racing 2t oil.

 

I bought neste-oil alkylate petrol for about 2eur / litre pump price.

They have produced it +23 years. ( by the way, who makes aspen petrol ? )

 

http://www.neste.fi/doc/130130_fi.pdf ( product data sheet in English)

http://www.neste.fi/doc/766111_fi.pdf ( 2T mix also available, 2% fully synthetic biodegradable,low smoke oil )

 

I asked about 2T oils , which provides the best protection and lubrication,the oil company said that the high quality racing oil is better,different than

fully synthetic biodegradable oils. (neste-oil 2T and Aspen 2T both use bio-2t oil.)

 

4t alkylate petrol prices in the UK,pump prices ?

Edited November 13, 2013 by Lasse

[Aspen@AAOIL]

Aspen Alkylate Petrol was launched in Sweden 1989 and is now produced in-house at Aspen HQ just outside Gothenburg.

 

More info and videos on it being made can be seen here.

 

A film about ASPEN (English) - SHORT

 

Alkylate is not yet available from a pump in the UK like it is in other parts of the UK.

[wyk]

The smoke is blue because it is an aerosol (colloidal suspension of solids in a gas), Particles of Incomplete Combustion finely dispersed in the exhaust such that they interfere with the light and appear blue in reflection. They are normally black soot based particles. This is similar to why a a similar suspension of oils in a liquid (i.e. milk an emulsion) is white.

 

In order for this to be true, the combustion chamber temperature in a modern two stroke would have to be below that required to ignite some of the petrol being used. Lets face it - the oil burns. It combusts. It ignites - as it would. It's basically a different form of petrol. It's not sludge in there, folks - it's two stroke oil. I have seen 'stock appearing' class race saws keep increasing their cutting times up to 32:1 ratios with fully synthetic oil without leaning. Some of the oil burns, some of it stays in the pan, some of it sticks to the rings and helps lubricate and increase compression.

Edited November 14, 2013 by wyk

[wyk]

BTW, just so we're clear. If you run your saw at 32:1 with synthetic - you will cake up your exhaust eventually. The manufacturers actually know what they are doing. Most, if not all synthetics, are meant to be run at 50:1 in an air cooled two stroke. The detergents, agents, and ash formulations are set up for a specific application. I would not go using random oils at random ratios for a specific task; chainsaws, in this case. A chainsaw is stopped and started and lashed about often, and all day long. Using an oil designed for race bikes, to be used at a constant high RPM with oil cooling or water for extended run times won't necessarily work well in a chainsaw that stops and starts and heat cycles like mad.

[GardenKit]

What theory says is one thing, and what happens is another.

 

Its blindingly obvious that the oil does not combust as easily as fuel. If it did we would not see the clouds of smoke that we see from an over generous mix, or the oily mess around the exhaust, or the coked exhausts, or the deposits on the piston crowns.

 

There is NO substitute for running the reccomended oil at the ratio that oil is designed to be run at.

 

In the case of horti/arb kit running on main brand oils conforming to JASO-FB, FC or FD this is 50:1, end of.

 

Why try to beat the system using fancy racing oils that are not formulated for our machines?

[Aussie treesmith]

I read up on this a while back and I was under the impression (by way of posted dyno testing results and discussions on forums etc) really lean mixes (100-1) are hotter and wear faster. More oil equals more power, better ring seal, more compression but only up to a point. Much richer mixes can cause fouled plugs, carbon build up, ring stick and scoring depending on the oil, tuning, use etc. There is also the idea floating about that 50-1 is more driven by emissions standards than by the best lubrication and 40-1 or even 32-1 may be a better mix for various reasons. I've read a few professional saw builders in America saying they run 40-1 or 32-1 full synthetic. I've run 50-1 Stihl mineral for twelve plus years with no trouble. Now on 40-1 but with modded saws.

The most important part seems to be that the fuel is clean and fresh well mixed with good oil and that the saw is tuned to the fuel used.

[wrsni]

Using an oil designed for race bikes, to be used at a constant high RPM with oil cooling or water for extended run times won't necessarily work well in a chainsaw that stops and starts and heat cycles like mad.

 

That's true, but most full synthetics aren't used or designed to be used in race bikes or at least ones that are pushed absolutely to the limit.

 

Firstly, if you're pushing it that far the full synthetics burn too clean and you'll have difficulties with "readability" of the plug for jetting purposes.

 

Secondly, if you get the oil company tech guys on a one to one basis they'll admit that they simply can't make a synthetic component to even match never mind exceed the anti-seize component of castor bean oil making it an essential component, so the most hard core racing two-stroke oils you can get, especially for an air-cooled engine, will be by default a semi-synthetic.

 

So the full synthetic motor cycle oils are actually designed for very high protection, but matched to clean running and a very high degree of practicality. It could be argued that they're a bit of an overkill for a chainsaw engine but if you're prepared to use it you couldn't use anything better with pump petrol.

 

To summarise, our friend is correct in saying that you wouldn't run the most extreme racing oils in a chainsaw, but the most extreme racing oils AREN'T full synthetics.

Edited November 15, 2013 by wrsni

[wyk]

You can get good semi synthetic 2 stroke oil suited specifically for chainsaw use. I use a semi synth at 40:1 in my ported saws here, and at 43:1 in the US(easier to mix it by the US Gallon with the little jugs ya get). I get a good burn, few deposits, and easy to tune and mix. And it's also very affordable.

 

Bear in mind that many hobbyist and builders running their saws at 32:1 have much higher than usual stock compression, some advance the ignition, and all should have mirror polishes on their exhaust ports.

 

I found this article interesting reading:

 

How 2 cycle aircraft engine oil works, what makes a good 2 stroke oil, two stroke air cooled engine oil, two stroke liquid cooled engine oil.

Edited November 15, 2013 by wyk

[openspaceman]

In order for this to be true, the combustion chamber temperature in a modern two stroke would have to be below that required to ignite some of the petrol being used. Lets face it - the oil burns. It combusts. It ignites - as it would. It's basically a different form of petrol. It's not sludge in there, folks - it's two stroke oil. I have seen 'stock appearing' class race saws keep increasing their cutting times up to 32:1 ratios with fully synthetic oil without leaning. Some of the oil burns, some of it stays in the pan, some of it sticks to the rings and helps lubricate and increase compression.

 

In order for what to be true?

[wyk]

In order for what to be true?

 

In order for the two stroke oil to not ignite at all, the chamber temperatures and pressures would have to be so low as to not completely burn the petrol as well. The pressure alone from the petrol igniting would ignite most oils, let alone the fact there is fire and spark and heat in there beforehand. The amount of unburnt fuel and oil pouring out of the exhaust at that point would simply be ridiculous.

 

Revisiting the 32:1 statement I made earlier. As I mentioned before regarding those mixtures - remember that many of the old school saws that asked for 32:1 or 25:1 had factory compressions in the 180-200psi range as well. I had an old McCulloch 7-10 that you could hold up by the starter handle and it would never unspool it. That thing had a ridiculous amount of torque. With a 20" bar on that 7-10, it was nearly impossible to stall it in the cut with a sharp chain.