32:1 mix for our older saws

[Vintage Engine Repairs]

If you want a screaming deamen on pro saws 48 mm piston or bigger 107 octane race fuel 40 to 1 think about the 12,000 to 13,000 rpms these baby's turn on high rpm or the stihl pre mixed is great for you stihl saw owners seen a saw that sit 5 years with pre mixed stihl fuel fired right up and run like a singer sewing machine or if you straight gas it by mistake some do this send to me for a full professionally rebuild and pro clean ultrasonic commercial cleaner. (Chain saw 101)***Rubber Duck PS Happy sawing safety first and just use common sense and service you equipment take care of it and those wood beavers will take Care of you.

You like your emoji’s!

I’m certainly not experienced on octane, though I don’t believe unmodified chainsaws have a high enough compression ratio or timing advance to warrant such a high octane. I think you’ll just end up with a slower flame front & combustion and although maybe not noticeable, you’ll technically be down on power because of it.

 

[jellyroll]

I run 87 i see no gains using higher octane except a lighter wallet.

 

[Rubber duck]

I run 87 i see no gains using higher octane except a lighter wallet.

Its cheaper in the long run you fill your tank up with 87 octane then 93 and see how much longer it will run on 93 plum empty tank you will use a whole lot more 87 than 93 I use to fo it on my z28 and would get 120 more miles out of a tank of gas I know that is a car just saying your saw you can run what ever you like .

 

[thompsoncustom]

Its cheaper in the long run you fill your tank up with 87 octane then 93 and see how much longer it will run on 93 plum empty tank you will use a whole lot more 87 than 93 I use to fo it on my z28 and would get 120 more miles out of a tank of gas I know that is a car just saying your saw you can run what ever you like .

Maybe if the 87 had ethanol in it and the 93 was pure gas or the car had adjustable timing. Total seal has a good video on it the only reason to need higher octane is compression or timing, no gains otherwise.

 

[Ironhorsedoctor]

Has anyone questioned the significance of using or not using high octane fuel other than premium fuel lightens up the wallet? If so I guess I missed it.
Mixing oil with fuel drops the octane value of the fuel and actually increases the compression. How much increase in compression?
I’m sure that has been figured out by the manufacturers and engineers. On the back of the Stihl silver bottle is printed a recommendation of 89 octane or better! Husqvarna premixed canned fuel printed on the can for all to read “ 95 OCTANE fuel rating before blending,estimated octane rating after blending is 93 octane “ Virtually all ethanol free engineered fuel is 90 octane or better is blended with a specific manufacturers Jaso FD oil and meets or exceeds equipment manufacturer specifications. Follow Husqvarna and Stihl’s lead that would undoubtedly drop a 87 octane fuel to effectively 85 octane! Fuel is also an effective coolant. Running a low octane fuel would cause an inaudible pre ignition and effectively an overheating condition resulting in premature mechanical failure. Premium fuel burns slower and cooler. There is a lot of Discussion on this forum about premium fuels including aviation fuel. E-fuel and the like. Is a slightly lighter wallet worth it? To me absolutely! The choice of fuels and of course 2 stroke oil is a personal choice! What ever combination you prefer just keep a sharp chain!

 

[rogue60]

Has anyone questioned the significance of using or not using high octane fuel other than premium fuel lightens up the wallet? If so I guess I missed it.
Mixing oil with fuel drops the octane value of the fuel and actually increases the compression. How much increase in compression?
I’m sure that has been figured out by the manufacturers and engineers. On the back of the Stihl silver bottle is printed a recommendation of 89 octane or better! Husqvarna premixed canned fuel printed on the can for all to read “ 95 OCTANE fuel rating before blending,estimated octane rating after blending is 93 octane “ Virtually all ethanol free engineered fuel is 90 octane or better is blended with a specific manufacturers Jaso FD oil and meets or exceeds equipment manufacturer specifications. Follow Husqvarna and Stihl’s lead that would undoubtedly drop a 87 octane fuel to effectively 85 octane! Fuel is also an effective coolant. Running a low octane fuel would cause an inaudible pre ignition and effectively an overheating condition resulting in premature mechanical failure. Premium fuel burns slower and cooler. There is a lot of Discussion on this forum about premium fuels including aviation fuel. E-fuel and the like. Is a slightly lighter wallet worth it? To me absolutely! The choice of fuels and of course 2 stroke oil is a personal choice! What ever combination you prefer just keep a sharp chain!

Omg the myth that high octane fuel burns slower will never die
All high octane fuel does different is have a better resistance too pre detonation. It's flame front burns just as fast as low octane fuel and in some cases high octane fuel can have a faster burning flame front... mind blown lol
Not sure why people persist with the old myth high octane fuel burns slower and ya lose power running it in a chainsaw as it's nothing more than fantasy.
Funny thing is people are scared of high octane as it burns slower "apparently" yet they will run dirty ethanol laced low octane fuel in their chainsaws completely ignoring the fact ethanol contains 30 percent less energy than straight gasoline.

 

[Okie]

I cannot run MY saws and any of my eq unless I mix the gas/oil myself.
I even do my own vehicle oil changes.

I see too many people now days playing with their cell phones instead of paying attention to what they should be doing.

 

[LegeaDejului]

I don’t have a older saw so I can’t say to be sure but I wouldn’t hesitate to use the the stihl 50:1 stuff In the gray bottle . Mixing oil is far superior than it use to be back then . Amsoil claims you can run their mixing oil 100:1 in anything and it will be fine


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They claim it will be fine and then don't follow up on the warranty for blown engines No thank you, they make great 4 stroke oils; 2 stroke, too much corporate ramblings. Oils got so much better over the years, yet they wanna negate that advancements by going higher mix ratio? Any synthetic oil or any brand can run 100:1 or even higher, but the moment the jetting gets a bit lean or the saw too hot, goodbye lubrication.

 

[Vintage Engine Repairs]

Omg the myth that high octane fuel burns slower will never die
All high octane fuel does different is have a better resistance too pre detonation. It's flame front burns just as fast as low octane fuel and in some cases high octane fuel can have a faster burning flame front... mind blown lol
Not sure why people persist with the old myth high octane fuel burns slower and ya lose power running it in a chainsaw as it's nothing more than fantasy.
Funny thing is people are scared of high octane as it burns slower "apparently" yet they will run dirty ethanol laced low octane fuel in their chainsaws completely ignoring the fact ethanol contains 30 percent less energy than straight gasoline.

I must admit I was under the impression, though I have very little knowledge on the topic, higher octane has a slower flame front hence why you run more ignition advance, to be able to get optimal flame front pushing against the piston?

 

[camel2019]

I run everything old and new at 32-1 tuned my equipment to it and not looking back.

 

[rogue60]

I must admit I was under the impression, though I have very little knowledge on the topic, higher octane has a slower flame front hence why you run more ignition advance, to be able to get optimal flame front pushing against the piston?

Yeah octane has nothing to do with how fast a fuel burns.
It's not hard to be confused about high octane on the internet's as so many repeat what granddad told em about high octane and that it burns slower than lower octane fuel which is not true. maybe it was in the 50's but not anymore lol
Once you start getting into the high octane canned fuels ie racing fuels they have much faster flame speed over low octane pump fuels. The octane rating tells you nothing about how fast a fuel burns.

 

[bwalker]

You like your emoji’s!

I’m certainly not experienced on octane, though I don’t believe unmodified chainsaws have a high enough compression ratio or timing advance to warrant such a high octane. I think you’ll just end up with a slower flame front & combustion and although maybe not noticeable, you’ll technically be down on power because of it.

Higher octane fuel doesn't burn any slower than low octane, period. In fact burning faster would tend to increase the octane rating.

 

[ZeroJunk]

Higher octane fuel doesn't burn any slower than low octane, period. In fact burning faster would tend to increase the octane rating.

Not necessarily. Octane rating is a knock rating , period. Higher octane is more uniform and consistent. Not faster, slower, hotter, colder, whatever. Traditionally, it was so for a 13.5 or higher compression ratio high performance car from back in the day would not spark knock.
If you are at 8.5 to 1 doesn't much matter.
I don't think any production car from 1970 forward was over 8.5 . So,

 

[bwalker]

Not necessarily. Octane rating is a knock rating , period. Higher octane is more uniform and consistent. Not faster, slower, hotter, colder, whatever. Traditionally, it was so for a 13.5 or higher compression ratio high performance car from back in the day would not spark knock.
If you are at 8.5 to 1 doesn't much matter.
I don't think any production car from 1970 forward was over 8.5 . So,

The statements I made are factual.
The statements you made in regards to consistency are and uniformity are not. Premium and regular are made with the same streams from the same units with only the ratios of each component tweaked to hit the octane numbers(and other parameters too)The recipe changes by the hour based on lab results and the "chemical soup" that is gasoline is anything but consistent.I know this because I make gasoline for a living and diesel too.
Also what phenomenon are you calling spark knock? When the engine diesels/knocks after its shut off?

 

[Vintage Engine Repairs]

Yeah octane has nothing to do with how fast a fuel burns.
It's not hard to be confused about high octane on the internet's as so many repeat what granddad told em about high octane and that it burns slower than lower octane fuel which is not true. maybe it was in the 50's but not anymore lol
Once you start getting into the high octane canned fuels ie racing fuels they have much faster flame speed over low octane pump fuels. The octane rating tells you nothing about how fast a fuel burns.

Thanks mate much appreciated. You learn something new every day!

Edit:

I was just saying to trains, the more I lean the more I realise the less I know.

 

[Vintage Engine Repairs]

Higher octane fuel doesn't burn any slower than low octane, period. In fact burning faster would tend to increase the octane rating.

Thanks for correcting me

 

[a. palmer jr.]

I run everything old and new at 32-1 tuned my equipment to it and not looking back.

I figured mine up the other day and it turns out mine is mixed at about 37:1.

 

[sawfarmer]

Not necessarily. Octane rating is a knock rating , period. Higher octane is more uniform and consistent. Not faster, slower, hotter, colder, whatever. Traditionally, it was so for a 13.5 or higher compression ratio high performance car from back in the day would not spark knock.
If you are at 8.5 to 1 doesn't much matter.
I don't think any production car from 1970 forward was over 8.5 . So,

 

[sawfarmer]

many cars truck gas engines today are 10 and even 11.5 compression ratio look at some of the new engine specs!

 

[ZeroJunk]

The statements I made are factual.
The statements you made in regards to consistency are and uniformity are not. Premium and regular are made with the same streams from the same units with only the ratios of each component tweaked to hit the octane numbers(and other parameters too)The recipe changes by the hour based on lab results and the "chemical soup" that is gasoline is anything but consistent.I know this because I make gasoline for a living and diesel too.
Also what phenomenon are you calling spark knock? When the engine diesels/knocks after its shut off?

I suppose you have never run regular gas in a hot rod with high compression and timed for performance. Put it in high gear at low speed, give it the fuel, and you will find out what spark knock is plenty fast.


There is no other purpose for octane rating other than to give the user or designer a way to anticipate pre detonation from high compression and two much advance.

Unless giving you something else to babble about incessantly is a purpose.