Fuel evaporation thread over on the Camaro forum

[VintageMusclecar]

I've often been asked about carbs with mysterious drainage/leak issues as evidenced by the need to crank the engine excessively after the car has sat for a week or so. General consensus seemed to indicate the carbs are leaking fuel internally (particularly in the case of QJets).

I've been meaning to perform a test like this for a while now but for a variety of reasons I've not gotten around to doing it...turns out someone beat me to it, and they posted the results over on the Camaro forums.

Click here (http://www.camaros.net/forums/showthread.php?p=2098945#post2098945)

This should help put a lot of old wife's tales to rest.

[VintageMusclecar]

FWIW, despite the OP stating the discoloration appeared to be more of a lighting issue to them, I have noticed a considerable change in fuel color (and aroma) in a matter of days in the fuel cell on my test engine.

[WILMASBOYL78]

As you all know the current ethanol based fuel is junk <<GRAEMLIN_URL>>/thumbsdown.gif

We have switched to using Av-Gas in all of our equipment and toys including lawn mowers, chainsaws, outboards, weed trimmer, snowmobiles, ATV, etc...no more carb problems...the Av-Gas lasts a long time with no discoloration or foul smell <<GRAEMLIN_URL>>/biggthumpup.gif

We also use it in the high compression cars and often blend in a little race fuel to make it perfect. Some of the gas stations in the upstate area of NY are now selling ethanol free high test...the snowmobile crowd is very grateful <<GRAEMLIN_URL>>/beers.gif

Wilma

***what can you do with old gas?? can it be recycled??

[Salvatore]

yes, Tommy the gas thing is an issue. I mix 112 Sunoco with 93 octane. cars run good and no problems all year long. My Q-Jet nova does need to crank way more times than the Holley on my Z/28. The 2 bottom plugs on the body have been epoxied over but still it seems to need to crank longer. I usually run 3+ gallons of 112 to about 10 gallons of 93.

[ktownkid]

I don't know anything about the evap. subject...but all items Tom mentioned...I had to have repaired, due to gummed up carbs and fuel systems. Now, I keep gas 30 days max...

If you don't stay on top of it...you will regret it...

ktownkid <<GRAEMLIN_URL>>/youguysrock.gif

[WILMASBOYL78]

The ethanol fuel works ok in our daily drivers because the gas is &quot;used up&quot; quickly...the longer this stuff sits, the worse it gets. Star-Tron is a good additive if you are stuck with ethanol.

wilma

[Mr.Nickey Nova]

Have the same problem with the Q-Jet on my L34 Nova.It's hard to start when sitting for three or more days.Have to crank the engine to reprime the carb and with a few pumps she fires right up.Now my 69 Z with the Holley can sit for a few weeks and with a few pumps fires up with no problem.. Maybe it has something to do with the size of the float bowl area,like do the Holley carbs hold more fuel than a Q-Jet???