Anyone Use Race Gas?

[tickhound93]

190 PSI and more is not an issue with pump gas, not even when turning 13,000 RPMs in the cut. Storability is another issue if your saw is setting for 6 months or more without running

No I know its not the psi on pump gas that will cause an issue brad, storability is also another reason I chose this fuel, it keeps very well in a sealed gas can, you know the lovy ones epa decides we need that don't let vapors out. My saws are gassed up year round, but I also run them at least once a week, so stale fuelnis never an issue for me. I wouldike to do cylinder temp comparisons between the pump gas I personally have available and the race fuel I run. As I see it, there are no I'll side effects to running the race gas, and it provides the lovely aroma of race fuel exhaust, magically delicious.
As my former employer and great friend likes to say about racing fuels, alcohol (ethanol) is for drinking, gasoline is for cleaning parts, nitro methane is for racing

 

[struggle]

I ran AV fuel 100 octane LL and while I liked the smell and the saws seemed to run OK they did seem to lose performance even on the ported saws. I went back to non-ethanol 91 octane unleaded. Your results may vary and opinions will be even further apart on this. Reputable builders will tell you there is no advantage to it for a reason. IF there was a major advantage everyone would be using it.

 

[IyaMan]

High octane is only necessary for high compression (over 11:1). High comp engines can run hotter, and the heat may cause pre-ignition with standard 87-90 octane fuel. High octane just means it burns at a higher temp. If anything, too high of octane might cause trouble with a cold start as most chainsaws are probably 8:1 (+/- 1).

Unless you drastically mod the squish or put in some sort of forced air injection, I don't think a chainsaw will ever have high enough compression to need over 91 octane, and will probably be fine with 87. (again 87 octane does not burn less powerful than 94). Its just a sales gimmic to make people who "love their cars" spend more on gas.

Finding compression ratio from psi readings involves a bit of math, but unless its over 170psi then normal gas is fine. Besides, if your air-cooled chainsaw engine is running hot enough to need 94+ octane, you're gonna have other things to worry about.

 

[IyaMan]

My 046 is pumping upwards of 190 psi of compression.

Wow, 190psi is pretty high! You may indeed need 92+ octane. Even 94+ if you factor in the oil mix potentially reducing the octane rating (though synthetic is usually not so much). Out of curiosity, any problems starting on a cold day with the 110 octane? Or overheating in the summer?

And for anyone interested, here's a psi to compression ratio chart (though its based on VE for a 4 stroke. I'm not sure if 2 stroke would be different).

Note: this is psi at sea level. You'll see lower psi at higher elevations

 

[BigMoneyGrip]

I wouldn't run leaded fuel, especially in a chainsaw where the exhaust is a couple of feet from your face at most.

The food that we put in our mouth is WAY more prone to causing health issues than fumes from a saw burning 100LL.

ETA: The whole "high octane has to have high compression" debate; Have you ever looked at the compression on most piston aircraft?

 

[Artemis]

My 445 starts cold on the first pull nearly every time! I run 94 thru it as well. My 372 doesn't give me trouble either. I agree, they don't need 94, but it's also free of ethanol, which is the main reason I use it.

 

[Chris-PA]

The food that we put in our mouth is WAY more prone to causing health issues than fumes from a saw burning 100LL.

In terms of relative danger you are just handwaving, and stating a logical fallacy anyway. I'm well aware of many of the dangers present in what passes for food in our industrial society, but the fact that other things in life are dangerous has no bearing on whether ingesting lead is bad for you. Especially since there is zero benefit to using leaded fuel in a chainsaw, and therefore no reason at all to expose oneself to it anyway.

The negative health effects of lead are rather well established, but feel free to ignore them.

 

[sunfish]

ETA: The whole "high octane has to have high compression" debate; Have you ever looked at the compression on most piston aircraft?

Enlighten us...

 

[sunfish]

Does it matter what someone else runs in their saws? Just run what makes ya feel good...

 

[struggle]

I run 91 octane only because it is the only e free fuel I can find from a place I trust


Sent from somewhere

 

[Artemis]

Does it matter what someone else runs in their saws? Just run what makes ya feel good...

It kind of does. That's how we learn. We try stuff out and share the ideas to find out which ones work and which ones don't.

 

[IyaMan]

The food that we put in our mouth is WAY more prone to causing health issues than fumes from a saw burning 100LL.
ETA: The whole "high octane has to have high compression" debate; Have you ever looked at the compression on most piston aircraft?

100LL in a saw will probably cause lead build up eventually and foul your plug. This is for a high comp or turbocharged airplane, a necessary consideration since high altitude has thinner air. Yeah, a piston aircraft may have 6:1 compression, but its turbo or supercharged.

But willingly to breath it? I think any doctor will say its better to eat a BigMac (but maybe not TacoBell).

 

[ChipChomper]

I know this is an old thread but... I tried Sunoco unleaded race gas with an octane rating of 100 and-- say what you may-- did experience better torque and overall power on a stock Dolmar 460. I was cutting in 36" solid red oak (yeah yeah i know i should have used a bigger saw) and it definately yielded a performance increase though at $7.50/ gallon it is certainly not an economical fuel choice. In the owner's manual for my Dolmar it says to use unleaded ethanol free gas of an octane rating of 100 or greater so I wanted to try it. Anyone had problems running premium 10% ethanol gas of 91-93 octane in their Dolmar? It doesn't seem all that worthwhile to run gas that is over twice the price even if there is some power increas. Thoughts?

Sent from my SM-T530NU using Tapatalk

 

[blsnelling]

Did you re-tune for the race gas? If not, then you are simply enjoying the benefits of the saw now running richer. Race gas requires a much leaner setting in order to achieve the same tune.

 

[CristiRo]

I know this is an old thread but... I tried Sunoco unleaded race gas with an octane rating of 100 and-- say what you may-- did experience better torque and overall power on a stock Dolmar 460. I was cutting in 36" solid red oak (yeah yeah i know i should have used a bigger saw) and it definately yielded a performance increase though at $7.50/ gallon it is certainly not an economical fuel choice. In the owner's manual for my Dolmar it says to use unleaded ethanol free gas of an octane rating of 100 or greater so I wanted to try it. Anyone had problems running premium 10% ethanol gas of 91-93 octane in their Dolmar? It doesn't seem all that worthwhile to run gas that is over twice the price even if there is some power increas. Thoughts?

Sent from my SM-T530NU using Tapatalk

I only use E10 95 Octane pump gas in my saws and have no problems.
I also have a friend with a Makita DCS 5121, also he uses the same gas as me, with Makita red oil ar 40:1 with no problems.
I've tried some higher octane fuel, but I really haven't seen any noticeable difference between them.

 

[Bostonstrongboy1965]

https://www.pure-gas.org/index.jsp

Someone sent me this link from a thread I started weeks ago.

 

[Bostonstrongboy1965]

Thread is>>> "Switching from street gas/oil mix to Ethanol free"; search it under my handle.