Subthread 32:1 vs 50:1 (heat data)

[don]

I appreciate this topic

The two biggest problems for me is getting the right chain (and keeping it sharp) for the job and fuel mixture.

Similar postings of this type have saved me allot of money on sharpening chains.

Also, instead of buying ten different bottles of oil mix and trying it out I learned from those people here on this site. They have way more tools / knowledge and experience on the subject matter than myself.

I cut several acres of valencia orange trees using the newer mix using synthetic the past couple of weeks and noticed a difference.
The saws are not as tired and they never acted up on a new batch of mix. Maybe it is because of a more conscious effort on my part to be careful with the mix. The net effect is I feel better and became more productive.

As far as the conflict as to what to or not post .. good luck Ford and Good luck Chevy!

Let me leave you with this experience of mine. I was on the board of a charity and we dispersed money to various areas of the community and world. So you could imagine how a parent of a local community would be angry or happy if we did or did not finance a blood drive / help with an operation / build some shelters or fund the translation of the bible in some dialect of a particular language. We wondered why people are so angry when we are giving money away.

We would remind ourselves of one strange conflict. There are these two very religious groups, Palestinians and the Israelites. God / scriptures / religious groups have told both of them they must punish those who are enemies. Even kill them. So who are the righteous?

I liked a politiacal satire about the answer to this when a reporter interviewed "GOD". God couldn't understand why nobody gets his message ... Thou shall not kill. It is a simple rule , right?

 

[Darin]

Mike,
What I think the Treegodfather is trying to say is that this whole website has continual repeated posts. This post in my opinion has a little more info on oil than many of the others. If we are going to complain about repeated posts, I think we probably could complain about the whole site. Guys if you want to complain about something, please contact me @ [email protected]. This will stop the misery you put everyone through when you complain publicly and every arboristsite nut has to chime in and tell you to get lost. It will always happen. Many of these guys take things to heart here and it causes nothing but problems. Thanks for trying to help.
NOW, let's get back to the topic.

 

[timberwolf]

Someone mentioned it earlyer, that the higher oil ratios contributed to increased compression ratio, could that be adding up to more heat as well?

TW

 

[Crofter]

Originally posted by timberwolf
Someone mentioned it earlyer, that the higher oil ratios contributed to increased compression ratio, could that be adding up to more heat as well?

TW . Extra oil might increase the compression of a worn saw but the compression RATIO is built into a saw and could only be changed by machining.

 

[timberwolf]

True, I guess the temps would be too high to have oil condencing out of the vapor mixture and building up in the head and reducing space.

You would also have fouling, smoking and oil dripping out of the muffler if it was taken to that extreme.

TW

 

[bwalker]

TW . Extra oil might increase the compression of a worn saw but the compression RATIO is built into a saw and could only be changed by machining.

Not so.It has been documented that more oil will increase the power of a two stroke through better ring seal/more compression.

 

[Crofter]

bwalker If you look at my post, I pointed out that oil could raise the compression but that COMPRESSION RATIO is a product of the fixed physical dimentions of the engine. The one is measured in pounds per sq. in. and the other is expressed as a ratio i.e. 9.5 to 1

 

[bwalker]

My bad I misread your post. BTW the incraese is not from incresed oil in the chamber. It is from superior ringseal. This was documented by a SAE paper authored by Mac in the 70's.

 

[Harley]

Whats the next test?

And when is it?

 

[tundraotto]

how about cylinder/crankcase temperature after say, 15s at full throttle and switch off for 20s. Then check the temperatures. Try synthetic and mineral oil and see if you get a temperature difference between the two.

 

[bwalker]

That would be a neat test Otto. It would be even better if you could add something like a water pump to the end of the bar that would simulate load. No load high rpm on a saw isnt really that stressful. I have a snowmobiles that I have egt gauges on. The sleds pipe has a stinger diameter that is to small for the cylinder size. This provides for really good excelleration, but you run into egt problems in about 20 seconds at wide open throttle when on glare ice. In heavy wet snow this time drops in half. Point of the whole matter is that load makes egt really rise in a two stroke. Maybe we could have somebody that mills do the test. That would be agood simulation of load.

 

[tundraotto]

Yep, even better Ben. I guess the key would be to have a load on the saw and keep the time, rpm level, starting temperature and ambient temperature identical as possible.

 

[timberwolf]

I could do the set up with the alaskan mill and 066, but I don't have any oil other than Stihl, Where can you get the other stuff?

TW

 

[bwalker]

Motul is available at motorcycle shops. Mobil can be had at autozone.

 

[tundraotto]

timberwolf, milling would be a pretty good test. You just have to make sure all the variables are the same. Mobil mx2t can be had at autozone for about $4 for a 20oz bottle. You probably would want someone to time the cuts etc. This would be a very interesting test!!!

 

[bwalker]

There is some anecdotal evidence that synthetics do run cooler, but in a two stroke this is not there main advantage. The advantage for a syn in a two stroke is that the can take more heat before they oxidize and when the do oxidixe the decomposition path they take is much cleaner. Dino oils tend to from carbon when they break down while syn usually just revert back to the components they where made from. In the case of esters this would be a alcohol and organic acid.

 

[Harley]

I've been thinking about this all day, and I came up with the same idea as you guys. Try different oils and see what happens to the temp on the cylinder. Only keep everything else the same as Otto said.

I also so thought that maybe trying different brands of gas might be a worth while thing to do.

 

[bwalker]

The thing about all these kind of tests is it hard to keep them valid as there are tons of variables that can scew results. The are a swag at best and total crap at worst.

 

[timberwolf]

A thought on gas

I dont think I would bring gas brands into the equasion. As gas is made up of as many as 100 ingrediendts There are far to many variables, even though it might be "esso premium" gas the formula might be different from one week to the next at any given gas station. The gas may come from a different manufactuting plant or even a different run from the same plant ect.

At least in Canada some manufactures also change formulations throught the year to accomdate climatic changes, so you never know exactly what the precentage of different formulations is in a gas stations storage tanks.

Timberwolf

 

[bwalker]

Not to mention the fact that just because the pump says esso thats what you are getting. The local mobile terminal which is accross the street from my work has every brand truck you can imagine pulling in there to fill up. The terminal itself gets its fuel by pipeline from a marathon/ashland refinery.