Not really. Even ported saws with upwards of 200 psi of compression are only at about 8.5:1
Ideal Chainsaw Fuel
- Thread starter MooneyPilot
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MooneyPilot
ArboristSite Operative
What you quoted pertains to advanced timing, not compression ratio. Advanced timing and/or increased compression ratio can cause the need for increased octane fuel.
MooneyPilot
ArboristSite Operative
Yes, avgas does indeed store very well. It makes a better solvent than mogas also.
And another 100ll user here. Those that know, use it and tune for it. Those that say it’s a waste of money or it makes less power are ignorant fools than can’t fathom anything beyond basic mods in a saw or any other 2stroke, or try to find some excuse based on what a saw porting, gasket deleting, carb adjusting “builder” told them (lol, the most basic elementary mods that anyone can do in their garage in under 2hrs on most 2 stroke engines)
I’ve used 100ll in small cc RC race engines at over 30,000rpm with great success (similar to 30% nitro mix at less than 1/4 the cost)
It works well and stores well.
You can use it in stock chainsaws with a quality oil mix and just slight carb adjustment and leave it for 5years and it will still start right up.
MooneyPilot
ArboristSite Operative
I’ve spent the last three days on disaster relief for a tornado in East Texas. Almost all of it in a bucket with a 200T and a ported 241. I keep a small plastic job box ready to go for these disasters. I packed the box after the last hurricane season which I think we finished in October, but maybe November. I had a gallon (I wish I had packed at least three) of 100LL and Stihl Ultra that I mixed in a well sealed gas can. The saws had gas in them that was more recent but it didn’t take long to use that up. I expect most folks will agree that it is extremely important for saws to start easily and quickly in a bucket. They started great and cut like crazy. I’m headed to get some 93 octane in the morning to mix, but will mix 100LL as soon as I get home and put it in the box.
I expect that the ultra has as much to do with it as the AVGAS, but this is my recipe from now on.
I expect that the ultra has as much to do with it as the AVGAS, but this is my recipe from now on.
Believe you like to toot your own horn jr. What rc engine you running to 30k that isnt a nitro?
Your insults are also not needed or welcome.
Second the shelf life of 100ll is one year, before oxidation start setting in, it will gum your engine up, and cause the gaskets and diaphragms to get hard just like non ethonal gas did. For some reason since the introduction of ethonal everyone thinks anything but high octane fuel goes bad overnight.
https://www.google.com/amp/s/generalaviationnews.com/2005/12/16/what-is-the-shelf-life-of-avgas/amp/
If properly sealed, 100ll will take over 5years to lose its octane to a point where it’s not usable in a chainsaw. Shelf life 1 year for planes for guaranteed safety reasons. I’m not referring to its use in planes here am I?
jr? Toot my own horn? You have no idea who I am, what I’ve built, nor what you are claiming. All you’ve spouted is nonsense/doubt.
TBS
I have chainsaws and chainsaw accessories.
For the rest of us who can't get avgas and are struck with e-10 or trufuel E-10 will last up to a year just fine if properly stored but beyond that why would anyone store a couple gallons that long.
Yet Sean is known and Respected here, where You have posted 4 times in 15 months, so, just who do you think that I am going listen too???
Someone a bit more credible than You that’s who. Show some Respect towards known members, contribute and show some knowledge, and you can Earn that Credibility too, we will give you that opportunity, but Respect has to be EARNED
Doug
I have spouted neither nonsense or doubt. All fuels have a shelf life. Full stop. Degradation doesnt stop just because it's in a sealed can. May slow it down, but it never stops. Back before the addition of ethonal in fuel we used to have the same discussions about fuel system problems. Typically not to the extent we see today, but it was nothing to hear someone having issues after storage from a gummed up carb.
Your not the only one that does port work, or is into rc that uses 2 strokes. I have to date never seen a gas powered 2 stroke hit 30k rpm. Never. Not at the races, not in boats that typically that use smaller displacement 23 cc engines that will sustain 20-23k rpm throughout the entirety on their race. Now if your talking about nitro then yep I can see that rpm.
Your base assumption that were all idiots because we dont use the fuel you do, and dont know anything about engines is disrespectful and arrogant.
Oh ok. It’s partial nonsense then. And you’re implying I stated things I did not (common uncomfortable response tactic), such as “everyone”
“shelf life of 100ll for using in chainsaw“ (did give a 5yr example, it’s probably longer for a stock chainsaw)
“all are idiots”
Interesting. How you do you deduce all that?
No disrespect meant. I was referring to herd mentality as “the way”. It will be the only way for many.
There are reasons some innovate or advance beyond and some will just follow.
What we‘re referring to here is the most basic form of 2stroke engines still produced (chainsaws and other similar power equipment)
Yep! Not surprised you had good results. I’ve been using 100ll for over 20 years in chainsaws and many other engines.
Very stable fuel and you can run a lot more oil in the mix as opposed to 87 (if you want or need to)
Exactly right. And besides octane, another thing few actually address when porting, raising compression, advancing timing is spark. They leave the same stock plug with stock gap. Well, that will work to a point. But why not change those and take it further?
While that is true that compression RATIO in a 2 stroke is much lower than the compression pressure would suggest for a 4 stroke, that does not mean it can be determined that since the ratio is low then it can’t benefit from a higher octane if tuned for it. Common misconception. If 2stroke race engine builders stuck with that belief they wouldn’t be where they are today regarding power output or rpm.
A piston/cylinder/combustion chamber is unaware of when a valve is closed or when a port is sealed during the stroke, it just builds pressure in which a fuel is introduced and ignited.
Ideal Chain Saw Fuel
Its Free
It contains no ethanol
It stores forever
It needs no mix oil
It smells good to the sensitive noses people seem to have now a days
It cleans parts super good
Cleans carbs and keeps diaphrams supple
It is like multi grade oil it automaticaly adjusts the octane rating to the saw
When you find this secret fuel let me know and I will buy lots but for now I will carry on with no ethanol pump gas.
Think of the bonus of this fuel
No more oil threads
No more fuel threads
what will we have to talk about?
Kash
Its Free
It contains no ethanol
It stores forever
It needs no mix oil
It smells good to the sensitive noses people seem to have now a days
It cleans parts super good
Cleans carbs and keeps diaphrams supple
It is like multi grade oil it automaticaly adjusts the octane rating to the saw
When you find this secret fuel let me know and I will buy lots but for now I will carry on with no ethanol pump gas.
Think of the bonus of this fuel
No more oil threads
No more fuel threads
what will we have to talk about?
Kash
For my money, any non ethanol fuel I can buy at the pump (all of it here is rated 89 octane or more) does everything I need. But there are a lot of places that non ethanol is not available. If that was true where I lived, I'd probably be buying AvGas to eliminate the ethanol issues.
That stuff burns my eyes and it cause some saws to idle incorrectly.
