Ethanol Based Reg Unleaded or Ethanol FREE Premium UL?

[mwarrior]

I've seen a few threads regarding the use of Unleaded versus Leaded on here...

And also that Lead was typically added for anti-knock as well as increasing octane. So my question is this, since the only LEADED fuel I can find without ethanol is 104 Octane (all the way to 118), what would be better? E-10 based Regular Unleaded (87 Octane using the "R+M/2" method), or Ethanol-Free 91 Octane Unleaded?

 

Or finally, one of the above with Lead Substitute on each tank? Fuel is going in a B80 in a Saracen if it matters.

 

Thanks

G

[fv1609]

G, I haven't answered your question but:

 

[David Herbert]

First, the octane rating of fuel is the measure of its tendancy to detonate during combustion (knocking or pinking). In addition to raising the octane rating, lead was added as a way of reducing the erosion of valves and seats. Contrary to many peoples belief, high octane fuel is actualy less "explosive" than low octane - that is the point of it.

 

As Clive has shown, the B series engines will happily burn any petrol available these days. In my experience you can run with the ignition significantly advanced compared to the official setting with noticable improvements to drivability and fuel consumption.

 

The issue with a Saracen is that the fuel pump (on the engine) has a long way to pull the fuel from the tank and the resulting level of suction makes the fuel seperate into the actual petrol and flamable gasses that are normaly disolved in it. The gasses get to the fuel pump and just get squashed and un-squashed, so no pumping happens. Result is fuel starvation. The simple solution is an electric pump at the tank wired into the ignition.

 

David

Edited August 22, 2014 by David Herbert