Two Stroke Oil Ratio Question

[charly]

Two stroke aviation engine maker disagrees with ya.

"Aviation Fuels

It is possible but not recommended to use 100LL AVGAS, since the the lead content will increase deposits in the combustion chamber and on crankshaft ball bearings, inducing premature wear. Its higher octane rating does not bring any significant advantage to the engine's operation"

Feeding your Rotax 2-Stroke Aircraft Engine

http://www.rotaxservice.com/rotax_tips/rotax_feed2.htm

Trouble is, they have to be torn down and carbonized with very low hours which once the plane is N Numbered, you can't do your self unless you have a Power plant rating... That get expensive... My friend has 560 hours on his Top 80 engine running premium auto gas and Amsoil Saber 2 stroke oil.. He said 100LL users go about 50 -60 hrs and they are installing new rings and pistons.. He sees it like clock work..

 

[Bigg_Redd]

None of my gear (saws, mower, dirt bike, etc) has a chronometer, but I've been running 100LL for 10+ years now. No scoring, no grooving, just easy starting, easy jetting, and zero carb issues.

 

[charly]

None of my gear (saws, mower, dirt bike, etc) has a chronometer, but I've been running 100LL for 10+ years now. No scoring, no grooving, just easy starting, easy jetting, and zero carb issues.

That's great... ! I'm thinking maybe jetting or timing changes are needed in order to burn the 100LL more completely.. Maybe issues with people who just use the fuel and do nothing to check exhaust temps or even do a plug reading.. I have 13 years on my Stihl pro saw with all original fuel lines carb parts etc. , runs like the day I bought it.. Premium fuel, seafoam, and amsoil saber.. Why change a thing? Same thing in your situation...

 

[BrotherBart]

I ain't ever flying with Bigg Redd.

 

[jharkin]

Every time these threads come up it amuses me. About the only thing a saw engine and a Lycoming have in common is they both have pistons... Why folks think they should use the same fuel....


I'm waiting for the day somebody tries to run a Stihl on Jet-A....


PS. If you have been breathing LL fumes for 10 years... Might want to get a blood lead test.

 

[BrotherBart]

I'm waiting for the day somebody tries to run a Stihl on Jet-A....

ETA: Well if Stihl ever gets around to building that saw with a T-55....

 

[Bigg_Redd]

Every time these threads come up it amuses me. About the only thing a saw engine and a Lycoming have in common is they both have pistons... Why folks think they should use the same fuel....


I'm waiting for the day somebody tries to run a Stihl on Jet-A....


PS. If you have been breathing LL fumes for 10 years... Might want to get a blood lead test.

1) You could say the same for automobile engines vs chainsaw engines, no?

2) Jet-A wouldn't hurt a saw. Because no saw would run on it.

3) Fun Fact: Most chainsaws ran on leaded fuel till about 1990 or so. But in any case I doubt the 5 gallons I go through every year are a measurable detriment.

 

[jharkin]

Low lead aviation fuel has a much higher lead content than leaded auto gas ever had. Almost 5 times as much. Its only low lead in comparison to the old 130 and 145 octane avgas formulas that had even higher percentages.

They have been actively trying to phase it out altogether inaviaqtion even due to health concerns and the plug fouling and other problems of the lead. They can't do so quickly because of the tens of thousands of old Lycoming, continental and other light plane engines that would need conversion.

 

[BrotherBart]

It is used in old aircraft engines because they were designed for it. It shouldn't be used in chainsaws because they were not designed for it.

BB - Who got his A&P ticket and then never used it.

 

[jharkin]

ETA: Well if Stihl ever gets around to building that saw with a T-55....

Shoehorn this bad boy into a saw and we could try it.

http://www.jetcatusa.com/spt5.html

 

[BrotherBart]

Too low final drive RPM but that would be a hoot in one of my little Husky 142s. Or as an APU to start my old 65cc Pioneer/Poulan.

 

[jharkin]

I did the math, its delivering about 10hp to the shaft at 7,000. Should have no problem starting that poulan

 

[BrotherBart]

I did the math, its delivering about 10hp to the shaft at 7,000. Should have no problem starting that poulan

Good because I do when I forget to punch the compression release on it.

 

[shawn6596]

@ 8oz per min thats a lot of fuel

 

[jharkin]

Yeah it is, its meant to power something like this:
http://www.rcuniverse.com/forum/rc-...latus-pc21-turboprop-build-9.html#post9755370

Jets are out of my league, those guys carry up to a gallon or more of fuel onboard for a 10 minute flight.