Blown Alcohol Air Fuel Ratios

Generally accepted is that gasoline is a 14:1 fuel and alcohol is a 6:1 fuel.

Bill

 

My guess is Fred Mandolini or Tom Conway would be best suited to answer those questions or perhaps Brad Anderson. If I was a betting man I would bet that Fred has actually done the most research of that particular type basede solely on what I have been told. I would contact each of them since none of really knows what they have done in the wee hours of the night.

Bill

 

I'd love to hear if you can find some solid info on this, I've been looking for a while now and haven't had much success. This is what I have learned -

Check out www.HRE.com - they claim 4.5:1 for best torque down low and pull fuel out to 6:1 for best power on the top.

A friend of mine runs a turbo alcohol 2.3 Ford and he runs 4.5:1 all the way through.

Watch what wideband you're using for comparison, they don't all read the same.

 

I was told that the best O2 sensors that money can buy have a limited range, and it seems that a Blown Alky engine probably runs outside this range (too rich). I assume that some of the fuel that goes into these engines is not able to be combusted in the short amount of time it's there, as the droplet size is too large - so it ends up being used basically as coolant for pistons, chambers , valves, etc.
I know of 2 guys who have run O2 sensors on Blown Alky engines - one of them claims he gets worthwhile data, the other guy took the sensors off because they fell off the scale under power every time.
These were on Aussie Doorslammers which are probably run richer than FC's or Dragsters because they are harder to get down the track.
If there is a sensor available that will read over a wider range, I'd be interested in trying it, but I've been told it's not possible.
Where did the sensor come from Mike ?

 

Mike you can also try giving norm drazy from psi a call he might be able to answer your question. just be ready for the long version.

 

I'm wondering if that's the problem with using a wideband on a blown alcohol as opposed to a turbo motor. I would think raw fuel coming out the pipes would affect the readings, on a turbo there is more heat in the pipes to help burn the excess.

I run a turbo alcohol motor and have noticed that even slight misfires (which put unburned fuel in the exh.) drop the EGT considerably, what would this do to a wideband reading?

 

Yes Dave, you just have to watch the Alky cars clear the pipes and stage - there is raw fuel just spraying out the pipes.
A long way from stoichometric I would say.