[Healeys] gas/alcohol

[Bob Spidell]

CORRECTION: Hank is correct in that ethanol isn't necessarily used to 
boost octane in pump gas--my assumption was incorrect--it's only added 
because of the federal mandate. It can raise octane, though the effect 
is probably minimal (the Penn State article didn't give the blend ratio, 
but 102 over 100 isn't much regardless). You can refine 100-octane gas 
from crude, but it would probably cost $10/gallon or more; and running 
E85 allows compression ratios to be raised for better efficiency and 
performance. That's why TEL was developed: to cheaply increase fuel 
detonation resistance while simultaneously poisoning every living thing 
on the planet.

In digging further, I came across this, which pretty much acknowledges 
what a lot of us suspected: ethanol in gas causes vapor lock, and not 
just in our Healeys. Also surprising to me, as ethanol has a lower vapor 
pressure than gasoline--I'd assumed the opposite--but blending them 
increases vapor pressure.

"... Gasoline vapor lock causes engines to stall, mostly when the car is 
in traffic and temperature is rising high. Similarly when a car is 
parked for a short period of time the heated motor won´t start. The 
higher the temperature, the higher the altitude, the more likely it is 
that Gasoline vapors build a vapor lock, preventing the fuel in the line 
from moving to the engine."

https://www.grabner-instruments.com/-/media/ametekgrabnerinstruments/files/pdfs/application--vapor-pressure--vl-ratio-of-gasolineethanol-blends.pdf?la=en&revision=00f78dc8-029e-4481-ba85-e640bdc7e338

Note there is some effort to change all gas to 93-octane only, which 
would accommodate all engines and simplify the refining and delivery 
process. We can hope, I guess.

Bob


On 9/2/2024 10:32 AM, Bob Spidell via Healeys wrote:
> "Ethanol boosts the octane number of fuel, which helps prevent 
> pre-ignition knock. Incidentally, the octane rating system for fuels 
> was originally developed by Penn State chemist Russell Marker in the 
> 1920s. The octane rating (Anti-Knock Index, AKI) of normal unleaded 
> gasoline in the United States is 87. The octane rating of pure ethanol 
> is 100. What's interesting is that when ethanol is blended with 
> gasoline, it performs as if its octane rating is 112, making ethanol a 
> very effective octane booster when used in gasoline. High octane is 
> one reason why NASCAR uses ethanol for their high-compression racing 
> engines. Engines that are designed and optimized for ethanol fuel have 
> the potential to run at higher efficiencies than engines designed for 
> and using gasoline."
>
> https://extension.psu.edu/fuel-ethanol-hero-or-villain
>
> On 9/2/2024 10:19 AM, Hank Leach wrote:
>> Ethanol will not raise the octane level of fuel-only the "tanes" 
>> shown on the chart affect boost and the higher the tane the more 
>> expensive the fuel.
>> If you procure fuel from an airport spout for road use there is a 
>> hefty fine (about $50K I think) and maybe jail time,  so they won't 
>> sell you any.  If clear gas (no eth) is not available you are stuck 
>> with ethanol. Hank
>>
>> --------------------
>>
>> From: "Bob Spidell via Healeys" <healeys at autox.team.net>
>> Reply-To: "Bob Spidell" <bspidell at comcast.net>
>> To: <healeys at autox.team.net>
>> Sent: September 2, 2024 at 10:02 AM PDT
>> Subject: Re: [Healeys] gas/alcohol
>> Living in California, I have been running 'gasahol' in all my cars 
>> longer than some. Best we can usually get is 91-octane; I was able to 
>> buy higher-octane--93 and 100--fuel at times but, guess what: the 
>> octane was boosted with ethanol (added water to some and measured 
>> before and after; don't recall the exact mix but IIRC I figured it 
>> was 10% ethanol; standard from the pump seems to be about 8%).
>>
>> I have about 140K miles on my BJ8 running mostly 91-octane gasahol, 
>> and there have been no negative effects save some 'vapor lock*' on 
>> starting when hot. I replaced the hard line to carburettor flex line 
>> that had been on the car for a couple decades and, except for it 
>> being a little stiff there was no visible degradation. About 8 years 
>> ago I put a new carb jet in pure/denatured ethanol and there is also 
>> no visible degradation. Rubber components sold since the introduction 
>> of gasahol are impervious to the stuff. Theoretically, due to its 
>> oxygen content gasahol could cause an engine to run a little lean, 
>> and at least one knowledgeable person recommends changing to rich 
>> carb needles, but both my cars have long since been tuned to run on 
>> it with std. needles. The BJ8 was rebuilt to standard 9.1:1 
>> compression ratio, the BN2 is a 100M and has the 'high compression' 
>> 8.7:1 pistons. I've been told Healeys will run fine on 91 up to about 
>> 11:1 compression, depending on the cam and timing.
>>
>> Good luck trying to 'steal' from an airport--when I owned airplanes I 
>> would occasionally get some--but the fuel providers aren't likely to 
>> be enthusiastic about selling it to you. Technically, you would owe 
>> 'road tax,' and the stuff is full of TEL and highly toxic (don't 
>> breathe any of it and don't let it get on your skin).
>>
>> * not technically 'vapor lock,' but the alcohol vaporizes and 
>> cavitates the fuel next to the exhaust manifold, causing some 
>> stumbling for a mile or so.
>>
>> Bob
>>
>> On 9/2/2024 7:45 AM, carl and gerry rubino via Healeys wrote:
>>
>>     A message from Canada. For the last 30 years I have been running
>>     my 100/6 on 93 gas with no alcohol.
>>     In its infinite wisdom our government is going to legislate
>>     alcohol in all grades of gas.
>>     Other than stealing gas from an airport any recommendations to
>>     deal with this?
>>
>
>
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