100 octane gas will "burn up" saw???
- Thread starter Plasmech
- Start date
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Woodie
"Cap'n Bullcrap'n"
Not the reason most want avgas at all.
It has no ethanol, and it can be stored for longer periods.
And no offense, but Stabil isn't worth the match it would take to burn it up.
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J.W Younger
ass kissing impaired
you did o.k. explaining it
You need less squish!!!
Well certainly more dry than ANY cornfed fuel, and by law they have to pump the tanks for water EVERY day. If you ice up at 20,000 ft it's not good.....
then drain the gas....most people on here have a big misunderstanding of higher octane fuels....ive been running ethanol in all of my stihl quickie saws for years ten plus and store them with it in the saw for 5 months in winter...no trouble yet.....the worst thing you can do to a saw is not use it..
Ske-bum
ArboristSite Operative
No, but the amounts of lead vary from type to type. The different types of fuel are dyed so that the octane can be checked at a glance.
There is 80/87 used in lower compression/hp and non-turbo charged engines ie; Piper Cub comes to mind. This will have the lowest lead content. Red in color.
The 100LL is for the rest of them. Blue in color.
Back in the 70-80's there used to 115, but haven't seen it around in a while this is for the BIG powerful piston engines and is purple in color.
Avfuel smells sweet when it is burning, I actually like the smell. Jet fuel not so much.
J.W Younger
ass kissing impaired
avgas does store better than pump gas and I have run it some in my saws since -I allways have it. If the fuel system is not clean it can cause problems pluggin stuff up, kinda like trans fluid will clean sludge out of an eng but end up plugin the pick-up strainer on the oil pump.anyway more octane than you need is kinda like retarding the ign timing.
i like your last statement
The engine is an air pump. Get as much air in there as possible, provided you put enough fuel in with it to use all the air up.
Oxygenated fuels bring extra oxygen into the engine (but you need to run more fuel through the carburetor to compensate) and should make a little more power.
You say you want my pistons hitting the cylinder head?
100LL has its place. I actually have several gallons here. I can think of a couple good reasons to use it. First, extended storage. I have 100LL in my old saws that will see liitle to no regular use. They may come out a couple times a year for GTG fun. Second, if you have an all out race saw with well over 200 PSI compression. How high I don't know. I've had more than one saw with 190 PSI that was fine on premium gasoline. Other than that, I can't think of any reasons that you would want to run 100LL.
The 115 is green, the really high octane stuff (130) is purple
PA Plumber
Addicted to ArboristSite
Maybe I missed it...
If the engine runs slower, does this mean the carb needs leaned out to get the rpm back? The saws still get the 4 stroke sound on wot with 100LL, and seem to cut fine under load.
My purpose for using 100LL is no ethanol and great shelf life.
I was planning to run it in the non-cat 4 stroke ATV, but the manual specifically says "Do not use Leaded Gasoline. Unleaded fuel Only."
If the engine runs slower, does this mean the carb needs leaned out to get the rpm back? The saws still get the 4 stroke sound on wot with 100LL, and seem to cut fine under load.
My purpose for using 100LL is no ethanol and great shelf life.
I was planning to run it in the non-cat 4 stroke ATV, but the manual specifically says "Do not use Leaded Gasoline. Unleaded fuel Only."
I've just found that the 100LL makes less power. It was not a tuning issue. I tuned the saw for whatever fuel was in it. I'll readily admit I'm in over my head here when it comes to explaining this scientifically.
Buckethead
ArboristSite Operative
Brad,
Your explanation may be total B.S. but, I understand what you're saying and it makes sense to me. I never considered that the saw may run slower with the higher octane but, obviously you've got the numbers to prove it. Have you collected any data on operating temps. with avgas?
When I switched to 100LL I thought my saw became "snappier" and showed more "guts." However, I also opened the carb 1/8 of a turn, put on a sharp chain with the rakers knocked down a bit, and switched to Stihl Ultra oil all at the same time. Unfortunately all of my "data" was very subjective and not reinforced with a single hard fact. Regardless of any performance improvement my goal with the switch to 100LL was to avoid any of the problems I've had with the E10 pump gas...in that regard I've been successful.
Do you think that you could mod a saw with high enough compression so that all of the benefits of 100LL would be realized?
There are plenty of racers out there than need more octane than pump gas provides. I don't think you'll do that with just a tight squish and your standard popup piston.
Buckethead
ArboristSite Operative
Brad,
If I were to try gathering some operating temp data for pump gas vs. Avgas would it be better to look at exhaust gas temp. or cylinder temp.??
If I were to try gathering some operating temp data for pump gas vs. Avgas would it be better to look at exhaust gas temp. or cylinder temp.??
Is this a test? Should I just go with my first gut reaction? Honestly, I don't know. I'd guess EGTs though.
Buckethead
ArboristSite Operative
Nope, not a test. Looking for the opinion of someone with way more experience than me.
I think my buddy has an old thermocouple temp gauge...I'll report back with my findings.
