661 Oil Test 32:1 vs 40:1 vs 50:1 ?

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redbull660 said:
The flash point has more to do with how quickly the oil is consumed by the combustion process and how it affects the octane rating of the fuel.




Don't know why you have to be such a jerk about it...

anyway -
  • The flash point of a chemical is the lowest temperature where enough fluid can evaporate to form a combustible concentration of gas.
The flash point is an indication of how easy a chemical may burn. Materials with higher flash points are less flammable or hazardous than chemicals with lower flash points.

http://www.engineeringtoolbox.com/flash-point-fuels-d_937.html

oil is a chemical.
oil is in that list.
oil burns.
oil is consumed by the combustion process. The flash point does have an indication of how quickly that happens .


would appreciate it, if in the future you would at least research what your saying before you say it.
Sorry if I came off sounding like a jerk, I was simply stating it as I see it.
 
You keep saying you need more power to do more work and I've asked you how you intend to get more power out of the saw and you haven't answered clearly.
Its been answered the entire time from several members and myself. Just because you don't get what you asked for when you asked for it does not mean it is not there
I've asked you to elaborate and all I get is nothing... Any time you feel like coming down out of the clouds to explain I'll listen. As far as I'm concerned there's not a lot of power left on the table once its tuned properly so where's the power coming from?
Marshy, since I have hit a nerve and you are getting yer panties twisted - lets review .........
Here is the exact order this went through ......... I will leave only the important stuff for ya
With a 20 inch bar i can tune like you are saying ,but my 75cc saw gets way to lean with the 32 or 36 inch bar buried ,so have to tune my particular saw richer to pull that bar ,i guess all i am saying is my particular saw seems to run the best with an oily muffler with a longer bar being run ,if i cut smaller stuff it is way too rich .
Interesting hypothesis you have regarding the need to adjust F/A ratio based on the bar size. What is your rational for this?
ANSWERED BLEOW
Quite simply ; more work needs more power to do that work
Simply adding more fuel will not equate to more work output.
That's not what was said Marshy.
Key detail from you below
I agree, heavy load makes more power with a richer fuel charge. Just seems silly to me you would adjust carb with different size bars. Reason I say that is because even with a shorter bar I can load the machine just as much as a longer bar but the feed pressure I put on the saw.
Please explain more in detail. You left a lot to be inferred.
ANSWERED BELOW
Try out a 32 some time ,make one pass in the 30 inch log ,and let me know how the saw pulls ,or if it leans out on you at all from the extra load from your settings with the 20 inch bar .
I think I can achieve the same loading with the 20" with more pressure. I think I'll just tune the saw once loaded in the cut and call it done. The F/A ratio doesnt change with the load being applied.
ANSWERD BELOW
Whats not to understand ?
To do more work you need to produce more power
Try what Brian suggested by running a longer bar in bigger wood and see if the saw likes more fuel. Your saw needs to be capable of utilizing that fuel, but somehow I think you already know that.
You cant simply "push harder" ................ you need more cutters engaged along the cut or the chainspeed needs to be increased, the rakers are at play in your "push harder" fallicy
Your missing my point. Blanket statements like yours might as well be false information. There is a point when more fuel doesn't equal more power.
ANSWERED BELOW AGAIN
Tune a saw with a 32-36" bar for that sized wood and check with a tach. Put a 20" on it and then see what it's turning. There's a difference with just the bars and chains resistance on the bar. If you tune pretty rich any way it won't matter but I try to tune with the longest bar I'll be running and leave it there.
Listen real good cause I am only gunna say it one more time for ya .............. as the load is increased you need more power to do the work. Simple;
Key detail from you below
As far as I'm concerned there's not a lot of power left on the table once its tuned properly so where's the power coming from?
ANSWERED YET AGAIN BELOW
Marshy the fuel can be too rich and lose power. Long cuts with long bars need more fuel than cutting 8x8". You can tune a 372 to 15.5k for cutting cookies and it is fine. Try that with a 32" bar and 30" of wood and it's toast. The hotter they get the leaner they get. I'm pretty sure that's the point Moparmyway is trying to make.

The mistake that I believe you are making is that I believe there is not 1 tune for a saw. The saw needs to be able to do the work. If it can make say 5 horsepower, yet only requires 1 hp to cut a small stick with a 12" bar, you will lean it out to have it 2 stroke in the cut, and 4 stroke out of the cut. That same saw with a 36" bar needs 5 hp to cut a 35" tree, and you are going to have to add fuel to get it to 2 stroke in the cut, and 4 stroke out of the cut. Hence more power is needed to do the work

Now, if your saw is a Mini Mac ......... you cant just add more fuel to a longer bar, the saw cant do the work, so it needs more time to get the work done. That saw just used more power (same power input over a longer time).
 
Mean while I've stated facts about air/fuel ratios and how too rich will lose power/torque. Although the graph I posted was in part emissions from Toyota its has valid information about best torque relative to air/fuel ratio. I'll repeat it incase you didn't catch it the first time. When adjusting your air to fuel ratio further rich, there is point of diminishing return where more fuel will not produce more power. Therefore your blanket statement and inference to add more fuel and get more power is not correct IMO and is misleading. Instead of being so defensive and ambiguous try reading, comprehending and validating some information and you might learn something new. There's a whole science behind internal combustion, specifically the science of air ad fuel is called Stoichiometry.

View attachment 419321
View attachment 419322
That 14.7 stoich does not apply to pump E10 fuels which have a stoich of 14.0-14.20. Lamda of 1.000 is stoich and .850 is usually 11.9-12.07 with pump E10 fuels. Most still go off the non E10 fuel so I thought this info may be of some help.
 
anyone have info on lowest temp some of these oils can be used at?

Stihl shows -38F "pour point". Not sure if that would be the number though.


I asked belray how low I could go with H1R...

Redbull says -

Sir,

is there a lowest temp stat that one would consider if you were using at say -30F below? yeah I know...but the truth is I have done cutting at those temps.
---------------------------------------------------------------------------------

Belray -

Yes we have that data for our 2-stroke oils. The H1-R experiences some additive dropout at -42°C (-44°F), but none was seen before that point during the cooldown range. Now, it may still be usable past that temperature as it wasn’t the entire bulk of oil that separated, but since some additives dropped out, we would not suggest running it at that temperature or lower because of the possible risk.
 
anyone have info on lowest temp some of these oils can be used at?

Stihl shows -38F "pour point". Not sure if that would be the number though.


I asked belray how low I could go with H1R...

Redbull says -

Sir,

is there a lowest temp stat that one would consider if you were using at say -30F below? yeah I know...but the truth is I have done cutting at those temps.
---------------------------------------------------------------------------------

Belray -

Yes we have that data for our 2-stroke oils. The H1-R experiences some additive dropout at -42°C (-44°F), but none was seen before that point during the cooldown range. Now, it may still be usable past that temperature as it wasn’t the entire bulk of oil that separated, but since some additives dropped out, we would not suggest running it at that temperature or lower because of the possible risk.
I'll never be cutting in those temperatures. Down here in Louisiana , below 40F is cold.
 
anyone have info on lowest temp some of these oils can be used at?

Stihl shows -38F "pour point". Not sure if that would be the number though.


I asked belray how low I could go with H1R...

Redbull says -

Sir,

is there a lowest temp stat that one would consider if you were using at say -30F below? yeah I know...but the truth is I have done cutting at those temps.
---------------------------------------------------------------------------------

Belray -

Yes we have that data for our 2-stroke oils. The H1-R experiences some additive dropout at -42°C (-44°F), but none was seen before that point during the cooldown range. Now, it may still be usable past that temperature as it wasn’t the entire bulk of oil that separated, but since some additives dropped out, we would not suggest running it at that temperature or lower because of the possible risk.
That's a good question to ask. I wouldn't worry about it with any oil other than castor or castor blend oils. With them I wood get nervous when the temp went south of 50 degrees and really nervous when it got below 40. I would also only mix up only enough fuel that I was going to use at one time as it tends to drop out of suspension when sitting.
 
This just proves that opinion's is like butt holes, everybodys got one and all of'em stinks.No one is ever gonna agree on everything,thats why there is 25 different types of automobile's, guns,tater chips,etc.. Just chose what you like and run it. Been running sthil synthetic 40;1 all my life in stocksaws.Now I have a few ported saws and my hero advised 32;1 would be better, so I choose belray h1r and have zero issues.Use to use that in my cr480 Honda years ago,13 14+k never any issues.All of todays oil is problay good,just pick what you like and go with it, no need to argue and fight about it.IT ALL GOOD AND LIFE IS SHORT (NO WORRIES) PEACE!!!!!!
 
That's a good question to ask. I wouldn't worry about it with any oil other than castor or castor blend oils. With them I wood get nervous when the temp went south of 50 degrees and really nervous when it got below 40. I would also only mix up only enough fuel that I was going to use at one time as it tends to drop out of suspension when sitting.
Had that problem with 927 castor racing arenacross in winter time over in idaho ,had to keep the bikes next to propane heaters ,when looked in the fuel cans could actually see the oil separating in the can when looked in there ,kept fouling plugs trying to start the bikes .was in the teens if i remember right .
 
Marshy the fuel can be too rich and lose power. Long cuts with long bars need more fuel than cutting 8x8". You can tune a 372 to 15.5k for cutting cookies and it is fine. Try that with a 32" bar and 30" of wood and it's toast. The hotter they get the leaner they get. I'm pretty sure that's the point Moparmyway is trying to make.

I disagree with his point (in bold). How would they get leaner? Is less fuel getting mixed with the incoming air charge or is more air being brought into the combustion chamber some how?
 
I cut every year in below zero weather. Saws run good and you don't have to worry about getting sweaty!
I prefer to cut firewood in cooler weather, below 50F to me, but usually that's hunting weather...squirrels and deer. I try to cut in the spring so it'll all be dry by fireplace time. If you run a little rich it'll keep the mosquitos off!
 
That 14.7 stoich does not apply to pump E10 fuels which have a stoich of 14.0-14.20. Lamda of 1.000 is stoich and .850 is usually 11.9-12.07 with pump E10 fuels. Most still go off the non E10 fuel so I thought this info may be of some help.
You bring up a good point because different fuels will differ in stoich. I run non-E but its 91 octane which would have a different stoich from 89 E-10 and subsiquently the two would have a different best torque curves.

My main point is adding more fuel does not give you more power if you've already optimized the air/fuel ratio. The only way to get more power from the engine is to burn more charge - the mixture of FUEL AND AIR.

The running limits of the engine are generally around lambda 1.2 on the lean side, and lambda 0.65 on the rich side. Outside of this region combustion becomes unstable, and eventually the engine starts to misfire as there is either too little or too much fuel for stable combustion.
 

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