Reference: “Notes from the field: Ethanol, Vapor Lock and other Gas Woes”

[Phil Waterman]

Hi Hanno

Thanks for pointing out the article, lots of common sense points raised, the type of thing where you say to yourself "I would have thought of that , eventually".

The key points of course are:

• Fresh fuel
• Summer blend fuel

Unfortunately we can't make ethanol fuel go away, and in defense of the gas companies I think it actually has gotten better over the last 15 years. For a while when it was introduced it was killing small engines and older engine right and left. Less so now, or may be it was a Darwinian thing and it just killed off all those engines that could not learn to burn it.

On thing I have noticed with ethanol gas is that it de-rates the out put of my gas generators by 20 to as much as 30 percent this is seen in power out put. The older the gas the worse it gets.

In engines the power loss in CMPs is not as noticeable as the loss in fuel mileage.

Now to the topic of vapor lock particularly with FORD flat heads, vapor lock in high heat when stopping engine was a significant problem. I can remember one fix that was pretty ingenious, add electric fuel pump at the gas tank, then put a pressure regulating valve at the carburetor with a return line to fuel tank. In this way if the fuel was going to boil because the engine compartment was to hot the excess fuel or vapor was taken back to the gas tank and fresh fuel was filling the line.

Cheers Phil