How does ethanol in gas affect 356 engine/fuel system?

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Ronald I. Maciejewski
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Re: How does ethanol in gas affect 356 engine/fuel system?

#46 Post by Ronald I. Maciejewski »

Sorry, forgot to mention that Marine Grade Stabil was specified.
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Bob Kittel
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Re: How does ethanol in gas affect 356 engine/fuel system?

#47 Post by Bob Kittel »

Read this on the net. Also read that the major auto makers are voiding their warantees on cars that have used E15. AAA came out with a statement to NOT use E15.

http://www.foxnews.com/leisure/2012/12/ ... -your-car/
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Re: How does ethanol in gas affect 356 engine/fuel system?

#48 Post by Richard Troy »

Hello Everyone,

I'm prepping for a trip from the San Francisco Bay Area to North Carolina and recall troubles on my last trip because I had failed to properly prepare for the alcohol in the fuel, quite aside from what I learned on a different such trip (to New Orleans that time) about the sometimes atrocious octane one REALLY gets, as opposed to what the pump's label says - but that's a different dialogue.

One crucial fact I learned last time was that the amount of alcohol changes, sometimes dramatically, and that (as a practical matter) it's virtually impossible to pick-and-choose real gasoline vs the various alcohol blends that may be available in any particular area. In April of last year I found from 0% to 20% alcohol in the fuel, and it seemed to me to get worse (more alcohol), the further east I went. The problem seems to begin (addition of alcohol) somewhere in mid-Texas, a bit west of San Antonio.

Therefore, my plan is to ignore the fine-tuning and just change main jets for "what gets me through the area without harming the engine." That means running it a bit fat, I suppose. I'm OK with that.

Just to make it easier to change the jets on the fly, I'm going with Webers since one doesn't have to dump a pint and more of fuel every time the jets need changing.

My plan is to be ready to change main jets every time I realize the alcohol content has changed significantly - and always assume the worst (some pumps are labeled saying, "may contain up to" some percentage, as opposed to stating what it actually is).

In general preparation for this - knowing it was coming - I decided I'd get some experience before the trip. So, I've been running around the S.F. Bay Area with 115 main jets for about a year. My first hunch was that'd be too lean, but it's what I had on hand, thought I'd try it, and they seem OK. I do notice two things, though, that seem at odds: 1) there's not much (but there is some) soot in the exhaust, and; 2) The fuel economy isn't as good as I got before with 120s in my Solexes and I find that puzzling.

Now, The Key Question(s)! Below, I'll make a few assertions and would like to hear agreement or disagreement, please! Note that I've mostly been running Solexes for the last three decades and don't have a lot of experience with Webers, so please forgive my ignorance:

Assertion 1: On the premise of no running faults and normal gasoline fuels, I'm going to guess that 115 is adequate, but if I want to spend the $, maybe 117.5 is also a reasonable (perhaps safer) baseline.

Assertion 2: Because one can plan on at most one main jet size decrease for altitude - to 5k feet - (with nothing higher on my route), changing the jet for this altitude change can be ignored because it only helps make it it run a little bit fat, which is safe. (In fact, if I leave in the 115s, I'm good on plain ole gasoline up to about 5K feet.)

Assertion 3: I should plan on two changes increase in main jet size for every 10% of alcohol.

Assertion 4: I can reasonably ignore the other (non-main) jets - I'm only passing through!

If this is more or less correct, I'm looking to bring the following main jets:
  • 115 - (the ones I already have) for regular gasoline near sea-level to 5k feet.
    120 - 10% alcohol.
    125 - 20% alcohol.
And that ought to do it.

Confirm / deny - anyone?

Thank you VERY MUCH for your insights.

Regards,
Richard
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Re: How does ethanol in gas affect 356 engine/fuel system?

#49 Post by George Walling »

Richard,first have a great trip, I have no experience with the webers but as you know I'm running zenith 32NDIX carbs on the engine you built for me and the only problem I've had is with the fuel boiling (Vapor Locking) from the fuel filter to the fuel pump so I would consider carring a couple of bottles of water with you to pour on that area if you experience that problem. I only have this problem when are air temp gets above 85*f. Just a side note the engine is running good and weather is changing for enjoying the Speedster.
Take Care George
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Re: How does ethanol in gas affect 356 engine/fuel system?

#50 Post by Brian R Adams »

Richard,

I am surprised that your gas in the bay Area does not have 10% alcohol year 'round.

Also, where would you expect to encounter 20% alcohol fuel?

FYI In Nevada (at least Washoe and Clark counties) we get "up to 10%" in the winter months only, but until sometime in November you shouldn't find any alcohol in our fuel, although I question the actual composition in both seasons, and find it impossible to dig out what's actually going into our tanks at any given time.

Brian
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Re: How does ethanol in gas affect 356 engine/fuel system?

#51 Post by Richard Troy »

Brian R Adams wrote:Richard,

I am surprised that your gas in the bay Area does not have 10% alcohol year 'round.

Also, where would you expect to encounter 20% alcohol fuel?

FYI In Nevada (at least Washoe and Clark counties) we get "up to 10%" in the winter months only, but until sometime in November you shouldn't find any alcohol in our fuel, although I question the actual composition in both seasons, and find it impossible to dig out what's actually going into our tanks at any given time.

Brian
Hi Brian,

as for local gasoline, I have a gas station literally one block away, and they carry straight gas. I admit that I don't always look for the sticker, though!

When I went to the last of the Space Shuttle launches, I went all the way to the Space Coast, and I found quite a few places that had 20%. I don't recall just how far west I first encountered it, but I'm going to say I first saw it somewhere in East Texas, headed eastbound. I recall with certainty seeing it along the gulf coast on into Florida, though 20% was the exception rather than the rule.

...I'm still hopeful someone can comment on the jet sizes vs percentages of alcohol!...
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Re: How does ethanol in gas affect 356 engine/fuel system?

#52 Post by Richard Troy »

George Walling wrote:Richard,first have a great trip, I have no experience with the webers but as you know I'm running zenith 32NDIX carbs on the engine you built for me and the only problem I've had is with the fuel boiling (Vapor Locking) from the fuel filter to the fuel pump so I would consider carring a couple of bottles of water with you to pour on that area if you experience that problem. I only have this problem when are air temp gets above 85*f. Just a side note the engine is running good and weather is changing for enjoying the Speedster.
Take Care George
Thanks, George. And I'm very glad that engine I built for you is running strong and that you're very happy...

...I think you might look into that vapor lock problem a little more deeply. Your first thing to check is where the metal fuel line that rounds the left side of the engine goes. You swapped that off your former engine, so I don't know how it's supported, but you want to make sure it can't pick up heat from the left head or from cylinder three's exhaust / heater system. Also make sure you aren't running lean. ...I recall from the images that it looks like your sheet-metal is all installed correctly. (Turn off any carburetor heating system!) And check that the fan belt isn't slipping!

Regards,
Richard
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Re: How does ethanol in gas affect 356 engine/fuel system?

#53 Post by George Walling »

Richard, I have a glass fuel filter and you can see the fuel boiling in it. all my fuel lines are clear of any heat source and I'm lucky as we have non ethanol fuel at quit a few stations here in Oregon and as long as I stay away from the ethanol I have no problem. I also have this problem with my 65 Barracuda when the weather warms up so I don't run the ethanol except when the good stuff isn't available, plus I get about 3 to 5 miles to a gallon more with the good stuff. But thanks for the information. Have a good trip. George
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Re: How does ethanol in gas affect 356 engine/fuel system?

#54 Post by Charlie White »

Richard,

"Land Speed Record Holder" for what?

CW
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Re: How does ethanol in gas affect 356 engine/fuel system?

#55 Post by Richard Troy »

Charlie White wrote:Richard,

"Land Speed Record Holder" for what?

CW
Hi Charlie!

On topic: I probably need to buy that Weber manual you provide!

And, in answer to your question, I've been campaigning a Denzel powered Karmann Ghia at Bonneville since 2009... You can read up here:

http://ghiacoachworks.com/share/denzel_lsr.html

Feel free to let me know what you think - 0ff-thread maybe!

Oh, by the way, I do both "356 Coachworks" and "Ghia Coachworks", if that isn't otherwise obvious!

Regards,
Richard
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Re: How does ethanol in gas affect 356 engine/fuel system?

#56 Post by Charlie White »

Very cool, Richard! Interesting website!

CW
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Re: How does ethanol in gas affect 356 engine/fuel system?

#57 Post by Richard Troy »

...I got an earful from a friend who knows something about running vehicles on alcohol, and rather than resolving the question of "ball park jet change per percentage of alcohol in fuel", it only served to muddy the waters.

It turns out there are different alcohols used in different mixtures and the effect of each on combustion is different.

That said, I'd STILL hope that there's some kind of ballpark estimate that's possible.

Anybody?

...My plan at present is to bring a pile of new spark plugs and try them out on various fuels as an inexpensive method of testing while under-way...

Regards,
Richard
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Re: How does ethanol in gas affect 356 engine/fuel system?

#58 Post by C J Murray »

Richard,
I drove an 1883cc 356 with 44mm Webers across the USA without changing the jetting. You will notice differences in performance but nothing drastic. If alcohol is 66%(?) of the energy of gas and is 10% of the total then you are changing the energy 3-4% for the fuel but you may be changing the fuel requirement more than that in the opposite direction when you are at higher elevation. I think you are over thinking/worrying the situation. If looking for perfection, you may change one jet size as an experiment. It only takes 5 minutes to change Weber jets which is less time then your math calculations. Remember, the idle jets control things to nearly 3000rpm.
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Re: How does ethanol in gas affect 356 engine/fuel system?

#59 Post by Sterling Vaden »

I think the highest percentage of ethanol you are likely to encounter is E10 or 10% ethanol blend in the US. E15 has only been authorized for 2001 and newer vehicles, and the infrastructure does not support multiple blends with the warnings and restrictions.

I would not worry about running too lean, but if you were, then just throw the 130's in it and forget it. Even back in the days of good (?) gas, we used to run 130 mains for better power. Seat of the pants tuning is no damn good at all for fine tuning main jets (IMO) so if you want to fine tune the mains, invest in a wideband lambda probe.

For practical purposes, you should have no problem with E10 as long as you keep it moving through the system. Let it set for a month or two and you will be cleaning idle jets and wondering why it keeps cutting out all the time.
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Re: How does ethanol in gas affect 356 engine/fuel system?

#60 Post by Fred Gruendig »

Richard,
Are you saying other alcohols "instead" of ethanol are used in gasoline today?
I was under the impression that when alcohol was added to gasoline to reduce emissions that alcohol was always ethanol.
Fred

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