I recently bought a parts car and pulled the sending unit out of the gas tank. I understand the car was sitting for 20 years but I'd never seen as good an example of just how bad old gas is at destroying the metal parts around it. You can't see it very well in the picture, but there is a line across the pick-up filter parallel to the edge of the corroded float edge, showing the level the fuel was at all those years.
Partially full metal fuel tanks vented to the atmosphere "breathe" with varying temperatures, and draw in humid nightime air, it condenses on the cool walls and sides of the tank. Quite a bit of water can ac***ulate this way.
I did a car that had been sitting for 15 years, the tank was a total mess and had to be replaced. I did another one that had been sitting for 30 years, the tank was OK. There are a lot of variables..if the tank breathes, that lets moisture in. If it's half full of gasahol, that really ****s the moisture in.
When E-85 first came out it was cheap so I jetted up a 3310 Holley and ran it my summer daily driver. Then cost of the E-85 went up and learned it was not worth the trouble after I wrecked a good fuel pump. (Too much Fuel pressure) internally regulated pump went nuts. Anyway when pulling the Holley apart to jet back for gas found the front bowl looked fine except the jets looked stripped and pitted. (front bowl was always in use) The rear Bowl was just ugly inside the bowl and jets was pitted and white corrosion. If I was still 16 the rear bowl would have as clean as the primary side but but it pulled in lots of water when not in use. The 10% ethanol in gas we get now in the pump is not quite as bad but if it sits long enough it gets ugly.
The Jalopy Journal
