E10 fuel and chainsaws?

[richyrich]

2 minutes ago, Dan Maynard said:

6 hours ago, richyrich said:

Local mechanic told me to stick with the new e10 and not use super as it will run too hot. 
Also says use a fuel stabiliser if keeping longer than a month.

I would like a proper explanation why this is, I can understand that super is no advantage but not why it should burn hotter if nothing else changes.

i have no idea- just thought i would take his advice as he is a qualified small engine mechanic. He might be wrong so open to any other ideas. I know petrol 'cools' an engine- as in a lean running one with not enough fuel compared with air will knack it up...but with regards to the Super running too hot- yes explanation needed.👍

[richyrich]

Fuel Types Explained – UK 2020

WWW.JCT600.CO.UK

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Are you confused by all the different car fuel types there are...

 

[neiln]

Esso synergy supreme 99+.  Esso have updated their website since the change to E10 but still clearly say the supreme is guaranteed ethanol free (except certain locations ...devon, cornwall and the far north iirc).  If you can't get Esso, use any premium fuel as its e5, I would suggest shell v-power, but bp ultimate or any other premium fuel is e5.  Use a stabilzer anyway with a fuel if leaving it, stabilizers slow the oxidation of the aromatics which cause the gumming.  Some stabilizers but not all (so check the labels) claim to help reduce ethanol problems.  Stihl green 2 stroke has a stabiliser in it BTW, but I add Star-tron too.  I've been using premium fuel in my saws for the last 4-5 years and haven't had any trouble.

 

I'm not expert but would think to run hot the saw would need to be lean, or the fuel be giving more oomph.  Ethanol has a lower calorific value than petrol but only slightly, the higher RON of the premium may slow the flame front a weenie bit and reduce the efficiency (or shave the key and advance the timing to compensate) but I can't really see premium being noticeably different.  Ethanol is less viscous than petrol so theoretically e free petrol through the same saw would run slightly leaner but again i can't imagine it would be noticeable...get your carb screwdriver out and adjust for e5..oh hang on...you've been on e5...adjut for e10 if you are running it or get used to a teenie bit more 4 stroking.

 

in summary, run premium fuel and esso if you can get it, and use a decent stabilizer what ever yu run, if you leave fuel round for more than a couple of months

[Haironyourchest]

Anyone know how good or bad the alleged built-in fuel stabilizer in Stihl HP oil is?

[Vedhoggar]

15 minutes ago, Haironyourchest said:

Anyone know how good or bad the alleged built-in fuel stabilizer in Stihl HP oil is?

I put that to a Stihl dealer a couple of years ago and the dealer told me Stihl would not say but he thought it might be up to a year. I've been using Stihl HP in machines on a regularly basis i.e. weekly/monthly and haven't experienced any problem mixing it with standard E5 petrol but with machines I do not use regularly its Ethanol free petrol. I have also been mixing for years the Ethanol Shield with standard E5 petrol for some 4-stroke engines without problem.

[Dan Maynard]

Fuel Types Explained – UK 2020

WWW.JCT600.CO.UK

---

Are you confused by all the different car fuel types there are...  

This is exactly the type of article that there are lots of, short on detail and not exactly right in everything that's there. You can tell that because they contradict each other in details.

As far as I know the higher RON doesn't require higher compression but it can stand higher compression without pre-ignition (also called pinking or knock), this means you can either build the engine with a higher compression ratio or use more turbo boost, and get more power.

In a lower compression engine the high RON petrol will burn when the spark starts it just like the lower RON petrol does, it's just a waste of money.

[Stubby]

10 hours ago, Dan Maynard said:

In a lower compression engine the high RON petrol will burn when the spark starts it just like the lower RON petrol does, it's just a waste of money.

I thought ( wrongly maybe )  that the high RON burnt slower than the lower RON so in a lower comp engine you got slightly less power  than if you used the standard faster burning fuel .

Edited September 16, 2021 by Stubby

[Deafhead]

Just filled my cans with E0 from North Heath service station near Pulborough, they said they are not going to stock E10.

[openspaceman]

9 hours ago, Stubby said:

I thought ( wrongly maybe )  that the high RON burnt slower than the lower RON so in a lower comp engine you got slightly less power  than if you used the standard faster burning fuel .

I don't think flame speed comes into it very much, I think higher RON fuels has a slightly lower calorific value,  it's just that the lower compression engine burns at much the same temperature but the power stroke expands from a lower initial pressure, so you get less work out of the heat put in. Conversely if you put a lower RON fuel in an engine that is designed for higher RON then as the piston compresses the fuel:air mix it may become hot enough for the fuel to ignite before the spark or, more likely, as the spark starts the combustion, the pressure and temperature from the expanding flame front detonates unburned fuel.

[woody paul]

Filled can this morning with E10 for the first time, filled blower this afternoon as tank was empty ran for about a minute and slowed and then stopped first thought was seized so chuck it on truck, nearly stopped on the way home and bought new one but didn't. Turned out screw had come loose and court on ignition fly wheel