Ethanol Jetting
 

Anybody have any thoughts/experiences with different jetting in a Zenith using ethanol fuel? I would think that possibly the idle jet and/or main jet may to be upsized?

Re: Ethanol Jetting
 

I see no need. JMO
Paul in CT

Re: Ethanol Jetting
 

Are you talking gas with up to 10% ethanol or E85 type that is 85% ethanol?
Ethanol makes about 1/2 the energy of gasoline so it takes nearly twice as much to make the same HP. That is in a modern car with much higher compression ratio.

Re: Ethanol Jetting
 

Now that we have an ethanol free pump near me, I only use ethanol free gas when available. I have noticed that gumming up the carburetor is a bigger problem with ethanol than a loss of power especially if the car sits for a few months during the off season. Ed

Re: Ethanol Jetting
 

i can't say I've noticed any difference in the old stuff.I've been working on old equipment for a living since the mid 70's,my main thing then was gummy carbs,and still is.I parked my 30 pickup one fall planning to drive it in the spring,but it didn't come back out for 7 years.It had a half tank of gas in it and I drove it to a station to top it off.That truck left a trail of stink behind it for weeks.The station across from the JD dealer I worked at started selling it in 1980,it was marketed as gasahol then.We all just used it,never gave it much thought.

Re: Ethanol Jetting
 

Like many things I ponder this is probably more a curiosity than anything else.... Yes, I’m talking about 10% ethanol. No, I’m not looking for 1 or 2 horsepower, I’m thinking about a good idle. Everything has to be just right for a banger to idle well and at idle there is so little fuel being used that 5% less energy might make a difference. At cruise it is possible to do some adjustment with the gas valve at idle all you can really do is lean it a bit with the idle air valve.

Re: Ethanol Jetting
 

Unless you’re racing for speed records, no need to worry. Your modern car doesn’t care, neither should you!

Re: Ethanol Jetting
 

Many many years ago I was on my way home from flying my model airplane in my 1929 closed cab pickup. It had a stock engine. I ran out of gas and poured a gallon of model airplane fuel in the tank, which is mostly methanol with some nitro methane and some caster oil. The truck ran fine with the GAV opened up at tad.

Re: Ethanol Jetting
 

I have been running 2 Model A's in the Commy State of New York on 15% Ethanol Gas since it was shoved up my derriere many years ago. Both cars run fine with out any changes to their Zenith carbs.

Re: Ethanol Jetting
 

I had the opportunity to do a loaded emission testing on my A, both before ethonal and after with the same car with no changes.
I have original jets that have never been flow tested.
on regular gas i could drive with the GAV closed, On the ethonal mix the GAV has to be opened 1/4 or it is too lean, 1/2 turn over 55
Jets that flow a little more than the flow rates in the books are probably better for use with ethonal blends

Re: Ethanol Jetting
 

Between the idle air mixture screw and the GAV, the variability you are looking for should be covered.

Re: Ethanol Jetting
 

I have not noticed that much difference; I was able to adjust the carb and No have any problems, but we live in mostly flat, very hot country,

Re: Ethanol Jetting
 

I had trouble with sticking valves on my tractor. Since then I use a little MMO in the gas of it and my Model A, no more problems!