I have a stock 1966 L72 427/425 with 11:1 compression. As such I run a mix of 50% leaded race fuel and 50% 93 octane unleaded. I noticed today that my station has a new "contains ethanol" sign on the pump. Should I be concerned re possible adverse effects on carb gaskets, rubber fuel lines or other issues ?
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Re: Ethanol + 66 427 = ?
Peter-----
Up to 15% ethanol should cause no problems, at all. I doubt that there's that great of a percentage in the 93 octane pump gasoline. However, even if it were that high, with your blending it would bring it down to 7-1/2%. So, I wouldn't anticipate any problems.In Appreciation of John Hinckley -
Re: Ethanol + 66 427 = ?
I wish we could buy 93 pump gas in California . 91 tops. I have to add Tetraethyle 130..Comment
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Re: Ethanol + 66 427 = ?
I am pumping 98 (with a lead replacement) here in the Netherlands - my 68 L71 runs great on it.
ErikComment
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Re: Ethanol + 66 427 = ?
US and European octane numbers are defined differently. European octane numbers are usually RON (research octane number), US octane numbers are average of RON and MON (motor octane number) calculated (RON+MON):2.
For some more information see
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Re: Ethanol + 66 427 = ?
Yes, the difference between RON used in Europe and PON used in the US is about 4-5 points, so 98 in Europe is equivalent to about 93-94 in the US.
RON was used in the US years ago, but the change to PON = (RON + MON)/2 was instituted in the late seventies or early eighties.
DukeComment
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Re: Ethanol + 66 427 = ?
Up to ten percent by volume ethanol is allowable is US gasoline. Ethanol is by far the most common oxygenate (now that MTBE had been banned) and is used in those fuel blends that require oxygenate. Ten percent ethanol by volume yields about 3 percent O2 in the fuel by mass.
Many areas of the country require oxygenate in winter fuels. In California we have about 2 percent oxygen year round so California gasoline is blended with about seven percent ethanol year round.
Ten percent ethanol gasoline (commonly called "gasohol") has been around since at least the early eighties in some markets, which predates the EPA oxygenate requirement. Ethanol is an octane enhancer, but the octane rating of base stock gasoline that is intended for ethanol blending is reduced so the final product with ethanol added meets the commonly sold PONs. This usually means the base stock has less aromatic HC compounds, which are considered carcinogenic, and aromatic reduction also helps to meet the lower vapor pressure requirements of modern gasoline.
Fuel system elastoners manufactured since the early eighties will handle this amount of ethanol with no problem, and I hope all of you have replaced your rubber fuel hoses since then.
Carburetor rebuild kits should likely have better materials, too, but those NOS rebuild kits from the sixties and seventies might be questionable.
DukeComment
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Re: Ethanol + 66 427 = ?
If the '67 does not have a re-circulating system like the current fuel injected cars I would not run the ethanol laced fuel at any percentage. The problem is vapor lock. Had that problem in my '57 and it left me stranded on the interstate highway. Not a fun day. The Ethanol does not hurt the engine but the ethanol will boil off first and cause vapor bubbles which in turn vapor locks the fuel system. If you do try it take along a rag and bottle of water and wrap around the fuel line and keep wet. If it is cool the problem is not so bad but I think the engines run hot in that confined space.
TedComment
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