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Dyno chat went to fuel octane? Fuel Octane

naked arborist

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Well, most of that was a waste to read. Does anyone want to really discuss fuel octane variables or the more important hot spots that most of these guys over there really have no idea about? I played the fuel game several times may moons ago. The only real changes I see are degraded performance as time goes on. I live on pump gas in everything. Only buy the 92-3 for the saws just to air on the safe side in killer hot weather. Most times they live on 89.

Enough of that crap.

Who has found that angling the squish has increased performance and cut down on detonation prone power losses with out pushing the timing and running av100? It's really just a practice in futility IMHO.
 
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Wigglesworth

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I'm a 87 non-ethanol guy myself. Never have had a problem. :)

I've cut squish at 2 degrees and flat and have never seen a difference from a performance standpoint. If I only had a Dyno....
 

thomas1

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I'd venture to guess that most of the guys who are arguing over the power differences in different fuels can't file a good chain.

If you're not getting detonation higher octane isn't helping anything.
 

Wigglesworth

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I'd venture to guess that most of the guys who are arguing over the power differences in different fuels can't file a good chain.

If you're not getting detonation higher octane isn't helping anything.

Funny story....

At my last gtg there was a certain 346 ported by a monkey from Tennessee that wanted to whip up on muh old stock 346. I didn't tell him what chain I was running, and when he finally finished his cut, I had already shut my saw off, sat it down and was leaned up on the cant watching him and yawning. I think he called me some bad names....


Chain is where it's at,

Octane...not so much. ;)
 

trx250r180

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how much compression do you guys run with 87 or 89 octain ? with over 200 psi more like 220 in some of my saws ,92 is low as i feel safe with
 

naked arborist

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how much compression do you guys run with 87 or 89 octain ? with over 200 psi more like 220 in some of my saws ,92 is low as i feel safe with

MM has got than fourumuulaa down pretty good. That we been using it with confidence (comfydence) for 30 years. Drop to 89. Feel the power on a lean tune.

The swept volume is so little in a two stroke stuff and under 3 1/2" bore in high compression four cycles it's rarely the issue to detonation.

Now hear THIS all you spiders, try it and burn one to the ground lol. Index your whole saw first and know what you have. If you don't follow what I'm saying, don't bother, I'm not esspainin-it.

Pump up timing while your at it spidy
Burn baby burn...
 

trx250r180

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MM has got than fourumuulaa down pretty good. That we been using it with confidence (comfydence) for 30 years. Drop to 89. Feel the power on a lean tune.

The swept volume is so little in a two stroke stuff and under 3 1/2" bore in high compression four cycles it's rarely the issue to detonation.

Now hear THIS all you spiders, try it and burn one to the ground lol. Index your whole saw first and know what you have. If you don't follow what I'm saying, don't bother, I'm not esspainin-it.

Pump up timing while your at it spidy
Burn baby burn...

out here ,the type of wood has soft fibres ,different cutting than other regions ,we also run longer bars ,if i run leaner for rpms i actually lose tourque over a rich adjusted saw like i run ,iv'e messed around with with my carb ,i don't have a tach but ,just adjust till pulls the hardest in a cut ,too much chain speed actually the teeth in the chain don't seem to bite into the doug fir wood fibres

also ,with the lower octain ,how long are you guys running the saws for ?4? 6 ? hours at a time ? a cutter out here normally runs a 6 hour day so a cooler running saw is important

i think Randy grinds my wood drift keys some on the timing ,saws seem fairly snappy like a dirt bike engine
 

WoodChuck'r

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I've gone back and forth on the fuel octane thing for years and years now. :retarded2:

For the past 4-5 years I've used nothing but VP C-12. It's expensive as hell @ $10.00/gal, but it's 108 octane and smells good when it burns and has a cool blue color to it. Literally that's it - not one saw I run needs that fuel, not at all whatsoever. I also add some R50 @ 28:1, because then that red oil makes the blue fuel turn a neat translucent purple. And wow does it ever smell amazing when it's burning. Ready to call me an idiot for keeping things in life so simple....?? Feel free. :D

But really, think it sounds insane...?? Yes it does. Because it is insane. But I like it, therefore I do it. Plain and simple. It's all in my head - I guess I just like 'thinking' my saws are getting the best treatment they can be given. Is it truly better over 87 pump gas with Stihl Ultra synthetic? I have no idea, and even if there is a difference, it's so damn tiny I'm more than phucking likely always going to be unable to measure it. And hell, maybe it's worse. But if it is, I guess I've got some saws to fix. Darn.

Some think I'm a farking idiot to spend that kind of money. Most will jump right to the argument that I'm not getting anymore power. They're probably right, and that's not why I do it. I've been given a ton of flack over the years from members that it's an utter waste, or a million other reasons why I'm not a smart person for doing so and there's no reason to put said fuel and oil in the fuel tanks of my saws. Once again, they very well may be right, and more power to them for ranting and lecturing me on the uber serious internet about it. The best part is I don't really give a phuck - at least my fuel smells good and looks cool..... ;)
 

BloodOnTheIce

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I don't know much about the science involved, and I'm not going to pretend I do.
But I'll tell you from my personal experience on the subject of fuel and octane.

I ran Klotz 98 octane can race fuel in my bikesaw for 2 years, and then switched to 91 octane
ethanol free from the pump and didn't see any noticeable difference in cut times. But at 15$ a gallon vs. 4.50$
I sure noticed it in my wallet.

In gas race saws all I've ever run was 91/93 octane and then spice it with some stuff on top
and go racing. Never bought 108 or 110 octane gas, never really saw the point in the 3x-5x
more expense to get it.

I try to run the ethanol free stuff in the shop, but it doesn't make any difference when they
don't run the saw for 9 months and it won't start ethanol free or not.

I went to a race in Pennsylvania 2 weeks ago, I ran my 288, and customers MS660 completely
stock, on pump gas with 9 tooth gears and race chains. The locals were running ported motors, nitro,
and every imaginable way of cheating. I won the 5.1-5.49 class by 1.5 seconds and
was 2nd in the 5.5+ class only because I had to blip it through the 3rd cut to not cut out and only lost by .2 of a second.

Chain and proper carb tuning are way more important to performance than fuel octane.
And I feel a stop watch and wood is the only dyno I need for a chainsaw.
 
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naked arborist

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Run what your confident with.
Nothing lost on good fuel as it keeps things clean, clean, clean!

I used to run av110 on and off road. When your dealing with 13.5 to one at 8,000 in a V8 it pays to cautious. A timing dump with pipes buttoned up during the week let me get by on 93 with a bump in it. Damn, that truck was fun with a stick.



Anyone have anything to add about hot spots they may have found on saws or other gas eaters?

Do any of you check exhaust temps?
 
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