[Bill Meyer]

I recently dynoed my freshened 474 and had some "old" gas left from last fall. Rather than waste it, I decided to bring it along and use it to break-in the engine until we got it close to max power. Since it was just pistons, rings and bearings, it didn't take too long to get it tuned-up. Then we put in the "fresh" gas, purchased that day -same brand, same pump, 110 leaded race gas, NO DIFFERENCE!! I had always thought that race gas lost something when stored for any length of time, but, just to make sure, we used the old gas again and actually stayed the same within 1 HP. The gas was stored all winter out of the sun and in a cold garage, so, I guess in this case, it's O.K. to use last years gas. ... BTW 657HP/613TQ... [img]/infopop/emoticons/icon_smile.gif[/img] [img]/infopop/emoticons/icon_smile.gif[/img] [img]/infopop/emoticons/icon_smile.gif[/img]

[Bill Meyer]

I recently dynoed my freshened 474 and had some "old" gas left from last fall. Rather than waste it, I decided to bring it along and use it to break-in the engine until we got it close to max power. Since it was just pistons, rings and bearings, it didn't take too long to get it tuned-up. Then we put in the "fresh" gas, purchased that day -same brand, same pump, 110 leaded race gas, NO DIFFERENCE!! I had always thought that race gas lost something when stored for any length of time, but, just to make sure, we used the old gas again and actually stayed the same within 1 HP. The gas was stored all winter out of the sun and in a cold garage, so, I guess in this case, it's O.K. to use last years gas. ... BTW 657HP/613TQ... [img]/infopop/emoticons/icon_smile.gif[/img] [img]/infopop/emoticons/icon_smile.gif[/img] [img]/infopop/emoticons/icon_smile.gif[/img]

[Tom Vaught]

The "Reed Vapor Pressure" (RVP) of the gasoline
will change as the vapors boil off over the normal
winter unless the gas tank or barrel is tightly sealed. I would have to pull out my Fuels and Lubes book to be totally correct but in basic terms Street gas and Racing gas have certain vapor
characteristics which allow quick start-up on a
cold morning, etc. Over time these characteristics
will be diminished if the gas is left open to the air. Harder starting will occur, etc. Now if you
have SOUR GAS, that is another story. In this case
the gasoline will physically start to break down
and water will be absorbed into the gas, the gas will begin creating varnishes, etc. I use one yr
old gas in my lawn mower all the time will no ill
effects except the harder starting. Tom V.

[Tom Vaught]

4 to 6 month gas is not OLD. Tom V.

[Half-Inch Stud]

Additives have been added to all gasoline to keep the gasoline from attacking & being attacked by copper/Bronze.

When the additives wear down (like from sitting in a freshly rebuilt crab) then the gasoline will skunk.

Otherwise, Tom vought said it.

H.I.