SOHC.co.uk Forums > Anorak's Corner
New E10/5 fuel
K2-K6:
--- Quote from: Johnwebley on July 03, 2020, 10:13:26 PM ---As the new petrol has added oxygen.
Do we need to enrich the mixture?
Guessing raise the needle one groove.
Maybe that is enough
Or hotter running plug.7 to an 8.
I would like comments from the clever guys.
Those far knowledgeable than me.
Thanks
Sent from my SM-A750FN using Tapatalk
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To comment on the mixture specifically;- Working with AFR (air fuel ratio) to hopefully give a concise view, petrol without the additional ethanol has a stoichiometric ratio (complete combustion of all fuel by ratio to air mix) of 14.7 to 1 , after which point there's too much air to match the fuel content. Most engines of the era we are concerned with don't run anywhere near that figure, more usually the standard jetting is more like 12.5 to 1 and richer than ideal.
E10 fuel has an equivalent of 14.04 to 1 taking into account the mix of components. The mixture if just left alone clearly now has a position closer to the stoichiometric value ( effectively making the combustion process leaner with this fuel).
A pragmatic approach is that the shift is just under 5%, and as the original factory jetting was running effectively too rich constantly, it's realistic to consider this as a desirable shift. It shouldn't, if the original setup is competent, give us any problems. But if you are concerned about it, a shift of one notch on the main jet needle could be assessed.
I though favour changing the spark plug heat range by going upwards one (ngk numbering) so 7 to 8. I don't do this because of conventional reasons of "running hotter" that is often inaccurate when used to suggest this.
I view it as the small resultant changes in effective jetting run a cleaner combustion process, and so reduces the demand for trying to keep the plug tip hot enough to make sure it doesn't foul.
In other words, you can take advantage of the change if effective fuel ratio and run the combustion closer to optimum.
An advantage of running a higher heat range plug is that it's more resistant to any affects of detonation (loss of control of the burn phase) and reduces the overall risk to the engine of consequence associated with this.
I've been doing this with an old car engine for some years which we've used in France, and commonly on E10 without any problem. Closely related in metallurgical terms to these bikes ( all aluminium construction with pushed in steel barrels, two valve per cylinder, offset spark plug, 9.35 to 1 compression etc) and as some of the linked comments suggest, it does run more efficiently on this fuel. General setup has been good for measured emmisions too whether E10 or not.
Oggie400F:
--- Quote from: gtmdriver on July 05, 2020, 07:53:28 AM ---Personally I use Ethomix from Frost Restoration and I drain the fuel system before I lay my bike up for the winter. These additives only protect the metal parts so you also need to look for biofuel compatible rubber hoses too.
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Interesting comments and I bow to both your and K2-K6’s knowledge and expertise.
I’ve ordered some Ethomix to give it a try. The description suggests that this is a good additive to combat the corrosive effects of Ethanol in fuel and it’s reassuring to know that it is endorsed by the FBHVC.
Do you know what biofuel compatible hose materials, apart from Viton, would be recommended and are readily available?
Ian
Tomb:
--- Quote from: K2-K6 on July 05, 2020, 11:46:39 AM ---
To comment on the mixture specifically;- Working with AFR (air fuel ratio) to hopefully give a concise view, petrol without the additional ethanol has a stoichiometric ratio (complete combustion of all fuel by ratio to air mix) of 14.7 to 1 , after which point there's too much air to match the fuel content. Most engines of the era we are concerned with don't run anywhere near that figure, more usually the standard jetting is more like 12.5 to 1 and richer than ideal.
E10 fuel has an equivalent of 14.04 to 1 taking into account the mix of components. The mixture if just left alone clearly now has a position closer to the stoichiometric value ( effectively making the combustion process leaner with this fuel).
A pragmatic approach is that the shift is just under 5%, and as the original factory jetting was running effectively too rich constantly, it's realistic to consider this as a desirable shift. It shouldn't, if the original setup is competent, give us any problems. But if you are concerned about it, a shift of one notch on the main jet needle could be assessed.
I though favour changing the spark plug heat range by going upwards one (ngk numbering) so 7 to 8. I don't do this because of conventional reasons of "running hotter" that is often inaccurate when used to suggest this.
I view it as the small resultant changes in effective jetting run a cleaner combustion process, and so reduces the demand for trying to keep the plug tip hot enough to make sure it doesn't foul.
In other words, you can take advantage of the change if effective fuel ratio and run the combustion closer to optimum.
An advantage of running a higher heat range plug is that it's more resistant to any affects of detonation (loss of control of the burn phase) and reduces the overall risk to the engine of consequence associated with this.
I've been doing this with an old car engine for some years which we've used in France, and commonly on E10 without any problem. Closely related in metallurgical terms to these bikes ( all aluminium construction with pushed in steel barrels, two valve per cylinder, offset spark plug, 9.35 to 1 compression etc) and as some of the linked comments suggest, it does run more efficiently on this fuel. General setup has been good for measured emmisions too whether E10 or not.
--- End quote ---
An excellent explaination, thank you. My experiences echo this, I've toured Europe for years and used the E10 fuel as soon as it was introduced over there on my 40 year old bikes, with no detrimental effect to running. There is the obvious corrosion effects but the question was mixture/fueling.
The one thing I have found over the 35 years of running my old bikes, from when they were not my old bikes, they were new, is the fuel consumption has steadily gone up with miles (104,000 on one and 86,000 on another). This obviously means mixture has slowly got richer as carbs have worn, so the E10 fuel has definitely made them run better.
The rich mixture is so bad on one bike I am now changing carbs and refurbing the originals.
My point is, as above, I think most old bikes will have the same issue as mine, rich running, so E10 fuel will be ok.
gtmdriver:
--- Quote from: Oggie400F on July 05, 2020, 03:28:12 PM ---
--- Quote from: gtmdriver on July 05, 2020, 07:53:28 AM ---
Do you know what biofuel compatible hose materials, apart from Viton, would be recommended and are readily available?
Ian
[/quote
Personally I use this.
https://www.ebay.co.uk/itm/100-BIO-Fuel-Hose-Petrol-Pipe-Ethanol-Butanol-Methanol-Diesel-Cohline-R9-R6-R10/251182149018?hash=item3a7b9f6d9a:g:PNkAAMXQn11RffRU]
--- End quote ---
--- End quote ---
Rob62:
Personally I avoid regular fuel like the plague.... premium fuel for your classic is the easiest way to avoid 10% ethanol.....for the time being at least.
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