Aside from the issues of tanks and other old rubber fittings getting dissolved, ethanol in smaller percentages [5 or 10%] is probably going to make the older I6 engines run better, when compared to today's basic retail petrols. Here in the UK we are looking at getting 10% ethanol fuel [as well as existing 5% ethanol already in use for many years], and there is a lot of weeping & gnashing of teeth going on in the old car world. [AKA classic cars, etc etc], with dire stories of fuel systems clogging up and breaking down, etc. [Any fuel system that hasn't had rubber hoses & gaskets, etc, replaced in the last 5 to 10 years surely is a dire lack of proper maintenance??]
Here in the UK, Manchester University conducted a series of in-depth tests on an old design of engine [which happened to be an MG XPAG, but the actual make/type is irrelevant] with the main objective being, to find out why old designs of engines fared so poorly on today's petrol?
The tests were conducted in a scientific manner [for discovery, comparison, etc], and came to some startling conclusions!
The real problem old designs of engines have is, today's petrol [with or without ethanol added], has a totally different make-up to the petrol sold in the 1960's! It has very different components! Especially when volatility of its head end components is considered. It is why common retail petrol doesn't have anything like the shelf-life of petrol from the 1960's! {I am assuming US petrol is much the same stuff as UK petrol here? I think it smells the same, anyway?}
Older designs of engines suffer from what is technically known as ''cyclic variability.''
With modern engines, engineers have gone to great lengths to reduce this phenomenon [using electronics for engine micro management]
This phenomenon as been made 'worse' in older engine designs by the changes in the content of modern petrol.
The Uni tests [led by a qualified engineer, who just happens to be an old car enthusiast!], compared the results using a variety of publically-available fuels [They had to go to France to buy E10 petrol!! The UK currently doesn't retail it] . These fuels included various super-fuels which are retailed by major oil companies....[not sure what they're called in the USA?}, as well as normal pump grades.
Most if not all, were unleaded [which is another issue entirely]
As expected, teh expensive [comparatively] top grade fuels performed reasonably well, but surprisingly, fuels with 5 or 10% ethanol did equally as well as the gucci petrols, in making the old engine [in design, it was fully overhauled to maker's spec before the tests were started], run much better.
They also found that the heat issue old engines now suffer from [but didn't, back in the day?]...had very little to do with minuscule evaporation in fuel lines or pumps [make a full flow fuel supply, like the Japanese did....with a continuous circulation, out & back to the tank?], and had more to do with the fact that, due to this cyclic variability thing being quite pronounced, exhaust temperatures were very much higher than wanted.
It is these high exhaust temps which heat up the carbs [heat soak, already mentioned here]....but not the entire carb!
Anyway, I've tried to source a USA link for the book which gives the chapter & verse on the test results, arrives at all sorts of unpalatable conclusions, but offers only tentative advice.
From the UK, the book is as per the link below.
Producing fine automotive books for nearly 30 years, we have plenty to share. Explore our books, blogs, and more.
www.veloce.co.uk
The book can be had cheaper elsewhere.
But please don't think it's purely someone else's viewpoint! Far from it, it tabulated the entire test results, findings, etc, and allows the reader to draw their own conclusions based on the facts of the matter.
Ooops, found a USA link..
Classic Engines, Modern Fuel: The Problems, the Solutions [Ireland, Paul] on Amazon.com. *FREE* shipping on qualifying offers. Classic Engines, Modern Fuel: The Problems, the Solutions
www.amazon.com
If one has an open mind about old [designs of] engines, then it is well worth reading and figuring out what is going on?
How to make our old bangers survive on 21st century petrol?
Me?
I'm looking forwards to trying 10% 95 octane pump fuel in my '67 Mustang...with its 200-6. The fuel lines are all made of modern materials so ought to be ethanol resistant....but it is not a tarty farty gucci car, but merely a nice , almost daily driver for an old fart like me [who spent his entire working life, aside from a brief spell, driving for a living, then becoming a specialist driver instructor to our military [including, on occasions, some of yours!!], so a reasonably spacious motor [I'm far from tiny in stature] with a nice auto gearbox [fed up with the left leg pumping up & down all day long]...suits me fine for now. [until my kids want the money for stuff, then I'd have to flog it]
My other passion is Ford sidevalve motors, of the small variety, in my Dellow. So I am somewhat daft in a way!
