steel fuel line buzz Options

[eyesright]

A coupe of years ago I replaced the original fuel lines with steel brake lines. It is a '72 with original FI and fuel pump relocated to the front by PO. I used a right angle fitting at the firewall rather than bend the line. On driving, the fuel lines buzz with a harmonic at all speeds that isn't nearly as prominent when not moving. I have covered the exposed lines with old rubber lines and secured them pretty well but no effect on a still noticeable buzz.

I am replacing the fuel lines now in a '76 and have steel lines long enough to bend.

If the harmonic buzz in the '72 is from cavitation at the right angle joint when there is significant fuel flow, then this should not occur with the '76. (I recognize that there is fuel circulation even at idle, but I don't get near as much harmonic buzz at idle. And it'a a much higher buzz than I would expect from road vibration.)

In the future I'll really tie those suckers down in the engine bay and where ever I can reach in the tunnel in the '72 to see if that helps or replace them with longer ones like the '76 if that is successful.

Has anyone had this problem or any ideas to offer?

[mr914]

I'm originally from Nebraska.

The corn hole state and Iowa have had ethanol since the mid to late 70's.

The only problem I've ever seen in regards to ethanol is that it was really, and I mean really, effective, at cleaning the fuel system and lead out of the carb/tank/lines

Today's fuel lines have multiple barriers to reduce emissions. For example, today's plastic fuel lines have 7 layers of different plastics, with different characteristics to keep the California emissions people from getting their panties in a bunch.

And yes, I have worked for a company that made fuel and brake lines.