More dyno action. 100 octane vs 92 octane

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Great work, mang.

Doesn't Ethanol have less BTU's per volume VS Gasoline? And did you test to see if it was 10% Ethanol by volume? Some places that have advertised 10% have tested up to 20%. Do they even regulate the amount of ethanol in fuel by testing for it at the state level? If your sample had a large amount of ethanol in it, then those results are skewed on the basis of octane.

Ethanol makes less power and raises the octane. It's political crap and doesn't belong in gasoline.
 
Chad, first off, thanks for doing this and sharing it !!! Question: is the 100 some kind of pump gas unleaded, or are you using 100LL Avgas? I have no source of non E fuel from any pumps around here. I can get canned fuel and avgas. I know you will try all kinds of stuff, really looking forward to Stihl MotoFuel supposedly Non E, long shelf life, pre-mixed with Ultra, and a decent octane rating can't remember the number. Thanks again, DW

The gas I got was at a sunoco station called gt 100 no e unleaded.
 
have you checked the exhaust temps with the race fuel vs pump gas ,a few timber fallers i know say they are lower with the race gas

No I didn't check temps. I didn't know anything about higher octane running cooler. I thought it was alcohol that runs cooler.
 
No I didn't check temps. I didn't know anything about higher octane running cooler. I thought it was alcohol that runs cooler.

i have not tested myself ,just going off what a couple fallers said ,when running all day ,may give some life to the saw if runs cooler ,think they were getting the fuel at the bike shops ,if anything it smells better :biggrin:
 
Fuel

Wanted to share this and might as well now.I got a tester "cheap bottle one" and did a test because of my nephew blowing three saws(he was using a farm store gas).I saw something in my test and my area Sunoco guy gave a # to call.They came out and tested and gave me results and some good things.He talks to me alot and knows I use E free on my saws but also now carries a bunch inside E free and wanted to share ,He told me all Sunoco's can get it.Also he just said the GT 100 is not E free.There is a chart inside.Dave PS different octanes all above 100 and like $80 for 5 gallon
 
Last edited:
Good stuff man!

I've tried 100 and tuned for it. All my saws feel stronger on 91 non-eth.

You tune for 100 octane by advancing the timing and increasing the compression. If your engine doesn't have those, you won't be needing high octane fuel.

Growing up in the 60's and 70's(OK, mostly 70's), some of us understand the need for high octane fuels. My first car was a 1966 Mustang that I stuffed a high compression 351 Windsor in to. 92 octane, leaded gas, was 65 cents a gallon back then.
 
Last edited by a moderator:
You tune for 100 octane by advancing the timing and increasing the compression. If your engine doesn't have those, you won't be needing high octane fuel.

Growing up in the 60's and 70's(OK, mostly 70's), some of us understand the need for high octane fuels. My first car was a 1966 Mustang that I stuffed a high compression 351 Windsor in to. 92 octane, leaded gas, was 65 cents a gallon back then.

No, I just tuned the carb.

My first car was a truck (mid 70s'), but then got a 1968 mustang and built a screamin 289 for it. I know all about the need for high octane with high compression. Later built a 351 Cleavland for a second mustang and went too high on compression. Would have been better off building a Windsor for that one.
 
With the dyno you could tell if running the chain pointing to the East improved chainspeed with less load due to earth rotation, or if the same results were achieved pointing the saw to the North. Or maybe it didnt matter because the chain running opposite direction on bottom of bar. But if you rand it on its side would it matter Northern Hemispere vs Southern Hemisphere.

I used to have a lot of spare time, but this move to the Country has me covered up for now. I'm grateful there are still folks with time to investigate these things. :msp_sleep:

Bill, quit whining about the country and lay off the pogue bait, drink water and get back to work. All these Internet breaks are killing your productivity.:msp_biggrin:

On another note, these dyno threads rock. I hope all the bugs get worked, data acquisition gets easier, and maybe, just maybe, some builders may post hard data on their saws.

Shea
 
With the dyno you could tell if running the chain pointing to the East improved chainspeed with less load due to earth rotation, or if the same results were achieved pointing the saw to the North. Or maybe it didnt matter because the chain running opposite direction on bottom of bar. But if you rand it on its side would it matter Northern Hemispere vs Southern Hemisphere.

I used to have a lot of spare time, but this move to the Country has me covered up for now. I'm grateful there are still folks with time to investigate these things. :msp_sleep:

Sounds like sniper school.
 
Not surprised at all.

In our race car world, its the same thing. More octane only allows more compression (or boost) and timing while avoiding detonation. Higher octane alone = richer mix = less power= lower exhaust temps.
 
Was the 92 E10? Even if not, AV fuel is formulated much differently than pump fuel. I would think AV would require leaning the carb.

Yes my saws run rich on 100LL. I'm glad to see that im not losing that much hp on my stock saws running 100LL. It cost's me $5/gallon and to me that small loss of HP is worth knowing I have fresh, pure, and consistent fuel for a reasonable price. How did you ever make out with the 660 vs the 460 now that you have the larger pump.
 
Last edited:
Chad, first off, thanks for doing this and sharing it !!! Question: is the 100 some kind of pump gas unleaded, or are you using 100LL Avgas? I have no source of non E fuel from any pumps around here. I can get canned fuel and avgas. I know you will try all kinds of stuff, really looking forward to Stihl MotoFuel supposedly Non E, long shelf life, pre-mixed with Ultra, and a decent octane rating can't remember the number. Thanks again, DW
DW
I get my 100LL at the Lock Haven airport. Currently about $5/gallon. I cannot feel an appreciable difference in power vs pump gas once it's re-tuned. My saws idle just a bit rougher but it's really minimal. After putting a carb kit in my brothers saw I will never run e10 gas again. Granted he neglected to run the carb dry before putting it away but it was full of mucous looking sludge.
 
Not surprised at all.

In our race car world, its the same thing. More octane only allows more compression (or boost) and timing while avoiding detonation. Higher octane alone = richer mix = less power= lower exhaust temps.

So octane is not a performance enhancement in itself but it does facilitate performance enhancements?
 
How did you ever make out with the 660 vs the 460 now that you have the larger pump.

Well I was planning on running the saws on Saturday but I blew my lawn mower up in mid mowing. 18 hp liquid cooled Kawasaki blew a gasket and ran the coolant out while I was mowing without any warning. I smelled something funny then it started to seized up and blew lots of blue smoke out the exhaust before shutting off. Just when I think I'm gaining ground on projects I get another one. Two young kids and a busy job keep me busy. I also live in a development and cant run my loud saws on the dyno at my house. I run them at work were my dyno's home is under my work bench. I'll try and test the 461 vs the 660 again now that I can easily pull the 660 down.
 
So octane is not a performance enhancement in itself but it does facilitate performance enhancements?

I think that are going to add octane to the list of drugs they check for in athletes.

Later
Dan
 
Brilliant stuff, I love facts, they can still be mis-interpreted or mis-construed but at least they began as hard data.

Down here we only produce 91 RON and 95 RON, 98 RON is available in major cities but is imported ex Australia or Singapore. No ethanol in the stuff we make locally (and I work in the only refinery in the entire country so tend to take a big interest).

You guys use an averaging method? AKI is it? I think that means our 95 RON is around your 90-91 AKI.

I'm interested because if I ever get my act together and send a saw north for porting, the builder will need an accurate fuel spec to build to.

Cheers, Adam.
 
Back
Top