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

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

#1 Post by Barry Brisco »

This topic is one of three new permanent "sticky" topics in the Main Discussion Forum. This topic is for an ongoing discussion of how ethanol in gas affects the 356 engine/fuel system. (It is not for discussion of the environmental and political issues relating to ethanol. Posts about that will be moved to Off Topic or removed if they violate 356Talk rules against political discussions.)

As long time 356Talk members know, certain topics are discussed over and over again. This is because the topics are obviously of interest to many 356 owners, and because it is not always easy to search the Forums and find earlier discussions of the topic.

Whenever a new topic is started about ethanol in gas and how it effects the 356 engine/fuel system that topic will be locked and then linked to this permanent sticky topic, where everyone is welcome to discuss that question and share their knowledge.

In this way, those posting about a frequently asked question are quickly directed to the permanent topic about that subject, where they can find a long history of discussion and hopefully answers to their question.

NOTE: in this permanent "sticky" topic, please keep your posts focused on the subject being discussed and avoid "me too" and "I agree!" type posts that do not add useful information to the discussion. Extraneous "chit chat" type posts in this topic are subject to removal. For more information, see this topic in the Forum and Site Q&A

Thank you.
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Re: How does ethanol in gas affect 356 engine/fuel system?

#2 Post by Barry Brisco »

Joseph Celeste wrote:Is it necessary to adjust carb mixture when switching from ethanol to non-ethanol fuel? I finally tried some non-ethanol gas in my 64 SC and in two days my plugs were severely fouled with black soot, indicating a super-rich condition. Correspondingly, the engine was misfiring, especially on acceleration. Cleaned the plugs and leaned out the carbs (Webers) and all is running well again, but don't know for how long while using this fuel. Is this common ??
Brian R Adams wrote:I think you answered your own question for all our benefit. Ethanol is an "oxygenator" and in essence (regurgitating what I've read here) it would make the car run somewhat leaner. The results of the experiment you described thus make perfect sense to me. However, in the course of making adjustments you could have inadvertently corrected something else that was really causing the problem.
Joseph Celeste wrote:I think you are right, Brian. I have a feeling I was on the edge of being too rich to start with, and when I put in the the non-ethanol gas it put me over the edge and fouled my plugs. I am back on ethanol and noticed the car is running better than it was originally, at this new leaner setting.

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

#3 Post by Barry Brisco »

Mike Hechinger wrote:Thanks to Bruce Baker and Dan Hayden for the prep at Hershey.
On the way home my "56 SRC died showing signs of fuel starvation. I always use a clear glass filter that is visible and cleanable. Sure enough the filter was dry. I then noticed that the hose from the fan shroul to the Euro heater was ripped and apparently overheating the engine compartment causing the fuel to evaporate. There were tiny bubbles (Una waka weeki, in the wine) coming from the fuel pump into the filter. I fixed the hose, filled the tank with cool gas and took off. Ten miles later, same thing. I stopped 200 feet from a motel so I borrowed 2 cups of ice and carefully packed one of them around the pump (OK, I didn't really, I just dumped it onto the pump but with the tin underneath it looked like it was designed to accept ice. Bubbles stop instantly and off we go the final 60 miles. I hate ethanol gas. My mileage goes down equally with the amount of ethanol in the gas.

What do I do in the future if I can't get pure gas?
Barry Brisco wrote:Mike, in the US I think most 356 owners regularly use "gasohol" and do not experience the problem you describe. Here in California I have no choice but to use gas with ethanol and I don't see what you describe.

Why do you thnk ethanol in gas is the reason for your problem?
Mike Hechinger wrote: I don't know exactly what was happening. Maybe it was just gas evaporating but doesn't ethanol boil off first? I think that the root problem was that the fuel pump got really hot and didn't cool enough until I put the ice on it.
Ron LaDow wrote:I don't think the ethanol will separate under normal running conditions. And in all the years I've fiddled with 356s, I've *never* had a problem with vapor lock.
I'd suggest you back away from any notion of what's causing the problem and see what the problem is. Are you sure the carbs were starved for gas?
Barry Brisco wrote:
Mike Hechinger wrote: I then noticed that the hose from the fan shroul to the Euro heater was ripped and apparently overheating the engine compartment causing the fuel to evaporate.
Mike, I'm not clear on how that would make the engine compartment get hot. If that hose was torn, all that would happen is that air at ambient temperature would be blown into the compartment before it passed over the cylinders, I think (and I could be wrong!).

It is true that the volume of air being blown over the cylinders would be decreased, so are you saying that what happened was that your engine got very hot because it wasn't getting enough cool air through that hose, which caused the engine compartment to get hot, which caused gas to boil in your fuel lines?

What did your oil temp gauge show when this happened? If you don't know that, how long had you been driving for?

What was the ambient air temp during your drive?
C J Murray wrote:When unleaded gas was mandated in the early '70s every car manufacturer started having vapor lock problems due to the much lower boiling point of the new fuel. I can not tell you if ethanol fuel is worse yet but maybe David Jones can inform us. The fix back in the '70s was to re-route the fuel lines away from the hotter parts of the engine and also to insulate the lines with aluminum clad foam insulation.

Generally 356s don't seem to have a vapor lock problem and that makes sense because giant amounts of fresh, cool air are being circulated in the engine compartment. I did however have one 356 that was prone to vapor lock and that car was equipped with Euro heat. The previous owner had made replacement carb heating tubes that did not have the valve to stop the hot air flow. The car was also running a bit lean at the time. During a hot highway trip from SE PA to the Michigan ECH the car was running poorly and very very hard to start at the gas stops. The fix was to block off the flow of hot air from the heat exchangers(boxes) to the carburetors. They are not needed unless you live at the Arctic Circle.

I think that vapor lock could also occur if the engine tin rubber seal was not in good shape allowing hot air from under the car to be drawn past the fuel lines while in hot climates in heavy traffic.

One other point-ethanol is crap!
David Jones wrote:Gasoline with ethanol is more volatile than gas without. However, all gas made for sale as "summer gas" is made to have a minimum boiling point of 95*F and a maximum vapor pressure of 7.8psi to 9 psi depending on exactly where you are located but in high density population areas the 7.8 psi is the norm.
Having said that the reasons for apparent vapor lock are either a high temp "hot spot" causing the fuel to boil at that point or a fuel line restriction causing a build up in pressure followed by a release in pressure which acts like when you remove the cap off a bottle of soda. The sudden drop in pressure causes the fuel to flash off resulting in vapor at a higher pressure which results in an empty fuel line. Add to this the leaner running that is a result of the ethanol addition and if your jets are on the lean side of the optimum then you could be more susceptible to vapor lock than those of us with more suitable jetting, as lean running means hotter running as well.
Matthew Devereux wrote:Is it possible that the fuel pump is weak?
Dave Wildrick wrote:
Mike Hechinger wrote: I always use a clear glass filter that is visible and cleanable. Sure enough the filter was dry........ There were tiny bubbles (Una waka weeki, in the wine) coming from the fuel pump into the filter.
I have the same glass filter after the pump in both of my C coupes. After a hard run, in both cars I get lots of bubbles (not necessarily small ones) in the gas in the filter. The motors get hot, but I don't have vapor lock problems. The cause of that in your motor may be something other than the ethanol content of the gas.
Brian R Adams wrote:Here are most of the known "pure gas" stations in the USA:

http://www.historicvehicle.org/Commissi ... re-Gas-Map

Support the HVA, stop the madness.
Robert Deutman wrote:I may have suffered a similar problem last weekend. Never had a problem with my 356 before, just had a full service from a long-standing 356 specialist (less than 1000 miles ago, car has been running beautifully every time), drove the car for 2 hours in city traffic at the first 90+ degree day in hot Bakersfield... and then suddenly the car stalled while accelerating. Restarted it 10 minutes later and drove off without problems, stalled again when I got close to my house. I'll drive it again later this week with a cold engine, see what happens. Gas tank is 3/4 full. Any ideas?
Matthew Devereux wrote:I've had similar problems on another car which had an electric pump. Are you running a mechanical or electrical pump? It was caused by a poor pump ground. The problem always seemed to occur when it was hot outside and the car had been driven for some time. Either way, checking fuel pump pressure when the problem occurs should go along way in troubleshooting.
Franny Brodigan wrote:For a little different take...

We had an event last weekend and ended up driving almost 1/2 tank through at RMPs greater than 3200 or so in our '58 normal with Zeniths. When we got home, we stopped by a friends house an chatted for about 15 min (engine off)... We started up the car to leave, still chatting for a few minutes and then drove off - sort of... The car would barely run - would not idle, but would spool past 3000 RPM, but with no power at all... It sure felt like a bad vapor lock. It sort of cleared up after about 1/4 mi and we got into the garage. The idle was really slow 4-600RPM and rough. I went back out a bit later and ran around the area a bit, but she just sounded tired - burbly, small backfires and rough. Then back to the garage and I did as I always do when I get these symptoms - clean the idle jets. I had just done this a couple days ago too... As usual, all was better. Idle back up and completely smooth. I did find one jet was almost blocked and was a bit of blowing and squirting to get it clean.

So,... Just another angle. Even with a <5000 mi fuel filter and cleaning the screen in the pump, I still get crap in the idle jets. I did have the carbs off to address some nagging seeping so I'm hoping that is all it was. Amazing how such a small hole in a part is so important...
Mike Horton wrote:Mike, David, Franny, all...I hate to tell you, but I've experienced the very same issues in my '68 stock U.S. spec 912, but only in hot (we had 107 yesterday) TX summer weather, on highway runs, and over a couple of year time frame, when I used my car in my weekly commute from Lubbock, TX, to Amarillo, when I was working at Bell Helicopter, a couple years ago. It would happen especially on a quick re-fuel stop. The car would re-start, but falter at about the end of the on ramp of the interstate, at an inopertune time. I am at 3300' elevation here in Lubbock, and can only get the offensive 10% ethanol. Amarillo is at about 3600' or so, and I'd had to jet up my smog tuned/split shaft Solexes, from the 55 idles, and 125 mains, to the solid shaft 57.5 idles, and to 127.5 mains. This altitude usually calls for approximately a one size smaller main, per the ancient Solex literature. I'd had to make these changes to maintain normal oil temps in the hot weather months. I then added a temporary electric fuel pump, with a dual position switch, on/momentary spring loaded on, much like the one Zim's sells, and operated it like a boost pump, like we had in light aircraft. I used it to fill the float bowls like many others, and learned that if I ran it for a couple of minutes after the "hot" re-fuel stop, I avoided the power interruption, and it sure acted to me like vapor lock I'd seen in other vehicles in the past. I did not run the electric pump, except under these conditions, and only for short periods. In milder weather, the engine driven pump is adequate. I have overhauled the carburetors, the engine driven fuel pump, the distributor, and replaced the rubber fuel hoses. I'm sorry, I did not pay attention to the fuel in the clear filter I run. After clearing the temporary fuel vapor issue, the car then ran as always, so I detected no jet clogging issues. I've never had these issues in my old 356 cars, but they were all run with real gasoline. I am going to replace the temporary electric pump with the new Carter pump, mounted under the tank, to push the fuel, using the same switch and procedures... interesting discussion...
Mike (old aircraft A&P mechanic)
Mike Hechinger wrote:Mike Hechinger responding,

Barry, I don't know if ethanol is the problem although I haven't played with the jets on my 40 IDFs since ethanol's inception. As for the hot engine compartment, the heat exchanger where the hose tore was right next to the fuel pump, maybe cool air flow through the exchanger keeps things cooler. I was driving for about 45 minutes with temps in the upper 80s and the temp gauge started to climb. I noticed that before the engine lost power.

Matt, the fuel pump is OK.

Robert, try what solved my problem, a cup of ice directly on the fuel pump solved the problem and it didn't return.

In conclusion, ethanol probably hurt the situation, once the fuel pump got really hot it would not cool off enough, even after I repaired the hose, until I iced it down. Also I filled the tank which puts cool fuel into the system and the higher level of fuel increases pressure slightly and I believe it will gravity feed the carbs even if the fuel pump is not working. I welcome comments on that last assertion.

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

#4 Post by John Pritz »

Thank you for taking the time to summarize the relevant posts!! Luckily we still have the choice to use non-ethanol gasoline here but that will probably change.

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

#5 Post by Tom Bridgers »

An alcohol (race) engine utilizes jet sizes that are approximately 2X that of a gas engine. Plug readings on my bikes have proven that they are running leaner with the ETOH mixture than a 100 octane no-lead fuel which is my poison of choice if no-ethanol fuel isn't available. At 15% Ethanol logic would suggest that the mixture is 15% leaner based on alcohol jetting. Fuel mileage also goes down accordingly.

For those of you who are infrequent drivers I would suggest keeping something around to boost it or even go so far as to keep a 55 gallon drum of no lead 100 octane around. Sunoco has it in bulk and any jobber should have it available. It stores well in the car and won't attack fuel lines. Sta-Bil, K100 and Startron are good additive choices. They are well known in the marine world.

OT but on point:

Only one racing tank company I'm familiar with has a liner that will tolerate both alcohol and regular racing fuel. That is ATL. The last conversation I had with Fuel Safe was that they had a liner that would tolerate alcohol but not racing fuel and one that would tolerate race fuel but not alcohol.
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Re: How does ethanol in gas affect 356 engine/fuel system?

#6 Post by Eric Cherneff »

Anecdotal observations:

I normally use ethanol-free premium, which is readily available in my province (British Columbia). After sitting for week(s), the car always fires up and quickly settles into a reasonable idle with the assistance of the hand throttle.

On two occasions, I filled up in Washington state, with an ethanol blend premium. Every time on startup after sitting for weeks, it coughed, sputtered, and would not settle into any kind of idle until it had been driven for a few minutes. Once I had used up the ethanol blend, the problem disappeared. I suppose changing the jetting and float height might have helped, but this illustrates the gas is different.
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Re: How does ethanol in gas affect 356 engine/fuel system?

#7 Post by Brian R Adams »

Since it settles down after warm-up, I doubt changing those settings will make much difference. It must be nice to have pure gas readily available. Shame on your country for allowing you to destroy the planet. ;-)
Welcome to the era of policy-based evidence-making.

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

#8 Post by Eric Cherneff »

Brian R Adams wrote:Since it settles down after warm-up, I doubt changing those settings will make much difference. It must be nice to have pure gas readily available. Shame on your country for allowing you to destroy the planet. ;-)
Not only is it ethanol free, it is 94 octane! Available at most (all?) Chevron gas stations in BC, if not elsewhere in the Great White North, eh.
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Re: How does ethanol in gas affect 356 engine/fuel system?

#9 Post by Stephen Moran »

We have had a 10% mix of ethanol added to Unleaded in Australia for some time now. Whilst my cars run fine on it, one thing it does do is kill fuel hoses. The ethanol makes normal braided fuel hose expand and it can slip off fuel pipes. We have high octane 98RON fuel here that doesn't have ethanol in, and I now use that in my cars.

Cheers

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

#10 Post by Ron Hoff »

A good friend and auto repair shop owner mentioned to me just yesterday that Gates is producing fuel line rated for ethanol fuels. It is called Barricade fuel line and should be available in both fuel injection and carb rated hoses. I'm sure other companies are also producing similar, but thought I'd pass on the name anyway. Change those old hoses!
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Re: How does ethanol in gas affect 356 engine/fuel system?

#11 Post by Ken King »

The Historic Vehicle Association has sent out an article about the damage caused by ethanol, and a recommendation to use a fuel additive to counter the harmful effects of ethanol, Shaeffer Oil’s Soy Ultra. There are other advantages claimed for this product. I have not noticed any problem from ethanol, but the author is a mechanic who claims he has seen damage to fuel tanks, fuel lines and fuel pumps. I am curious to know if anyone has had any experience with this or other products. I have found that Eastwood also has a product for protection from ethanol damage (Fuel Guard).
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Re: How does ethanol in gas affect 356 engine/fuel system?

#12 Post by Glenn Ring »

I recently spoke to Art Thraen about how E10 attacks rubber and pointed out that IDAs have the least rubber seals with IDFs next and Dellorto having the most.

My local lawn equipment shop had to rebuild the carb in my lawn mower due to E10 eating away the fuel line and carb gaskets in the 3 years i've hand it. He suggest adding a fuel stabilizer and using 91 octane to counteract the harmful effects of E10.

5 years ago would you ever thought that good gas and oil would be hard to get.
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Re: How does ethanol in gas affect 356 engine/fuel system?

#13 Post by Erik Madsen »

One of the things I have been doign with my customers is using the SEF94 VP fuel in their cars for winter storage. While the SEF is not cheap, it is sold by the 5 gallon pail (or 55 if you wish) and seems to cure most of the problems with long term storage as well as rubber degradation. While during the short drive season, E10 is being used, we have to deal with hose damage, it is much reduced using this fuel.

Please also be aware of Ethanol phase separation. I wrote a post about this sometime back, but the short of it is E10 is good for aboiut 21 days + or - due to Delta T. So, for those of you that fill up every 2 months (hopefully you get to drive more than that) Ethonol concentrations can be significant, as well as water being absorbed, as ethanol is hygroscopic. Acidic corrosion is a certain occurance, and I have been taking carbs apart and noticing significant microbiological growth (green) as well as white corrosion on carb bodies. These are the signs.

My customers have had very good luck using the following products: Startron (contains an enzyme which reduces phase separation), Sta Bil (new formula "FOR ETHANOL", Spectro Oils "Fuel Stabilizer", this one has become my mainstay. I have seen the best results using the Spectro product (no affiliation).

As for settings, there are many posts on this already, but remember that Ethonol produces about 67% of the BTU's as straight gasoline does.

Good Luck,


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

#14 Post by Paul Hatfield »

Here is an interesting video about the attack Ethanol can make on various parts:
http://www.historicvehicle.org/Latest-N ... lassic-car
-Paul
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Re: How does ethanol in gas affect 356 engine/fuel system?

#15 Post by Tom Bridgers »

Erik Madsen wrote:One of the things I have been doign with my customers is using the SEF94 VP fuel in their cars for winter storage. While the SEF is not cheap, it is sold by the 5 gallon pail (or 55 if you wish) and seems to cure most of the problems with long term storage as well as rubber degradation. While during the short drive season, E10 is being used, we have to deal with hose damage, it is much reduced using this fuel.

Please also be aware of Ethanol phase separation. I wrote a post about this sometime back, but the short of it is E10 is good for aboiut 21 days + or - due to Delta T. So, for those of you that fill up every 2 months (hopefully you get to drive more than that) Ethonol concentrations can be significant, as well as water being absorbed, as ethanol is hygroscopic. Acidic corrosion is a certain occurance, and I have been taking carbs apart and noticing significant microbiological growth (green) as well as white corrosion on carb bodies. These are the signs.

My customers have had very good luck using the following products: Startron (contains an enzyme which reduces phase separation), Sta Bil (new formula "FOR ETHANOL", Spectro Oils "Fuel Stabilizer", this one has become my mainstay. I have seen the best results using the Spectro product (no affiliation).

As for settings, there are many posts on this already, but remember that Ethonol produces about 67% of the BTU's as straight gasoline does.

Good Luck,


Erik Madsen
Riva Ridge Motorsport

Great advice.

Tom
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