Just took chevelle for a 10 mile ride yesterday after a long winters nap. after returning and parking it an hour later the garage reaked of raw gas fumes. There are no visible leaks anywhere in the fuel lines. Here are the rest of the stats BB chevy 750 man sec. Holley 750 dual metering blocks 2.5 power valve
( only 5-6 in. vacuum @idle) stock jets, manual Hi-perf pump with 6 1/2 psi at the inlet to the dual feed line to the carb. Float levels in sightglass at idle are just a hair over half full. Is it possible for the carb to continue to leak raw gas into the manifold when shut off? If so, does anyone know what to look for to repair the problem. I have always suspected the carb was leaking into the manifold because in the past when I would shut it off and start it an hour or so later it would turn over like it was hot or the timing was off( which neither was true ). Does anyone have any suggestions or clues? Thanks, Pat

ph71ss@yahoo.com

Check your float level.

Thanks, just edited my post. floats are set at 1/2 to just a hair higher in sightglasses

Thanks, just edited my post. floats are set at 1/2 to just a hair higher in sightglasseshow about a bad power valve in the carb

PH71SS,

Your float levels should be set so that if you nudge the car you see fuel at the BOTTOM of the sight glass. Half way up in the sight glass is way high and yes, it will lead to smells in the garage.

While you are at it, tell me all about the engine.....
Unless you have a GODZILLA cam in there, you should have better vacuum.
So, tell me about your combo, your ign system, converter, etc, etc....
Be very specific....
We're gonna get your vaccuum up and get you some better driving manners, less smell and more performance.

Regards

it's a pretty good combination 030 over 402 Rect.port heads 219-188 with pocket porting and bowl blending crower solid flat tappet 580 lift 296 duration not sure of the other specs on cam it was in there when I bought it Weiand team g single plane 750 holley mech. secondary Accel dist with MSD 6al 10 in conv 3500 stall with a 700R4 and 410's with 29 in tires. car runs great just have to get rid of the gas smell. I've now adjusted the floats to the bottom of the sight plugs so that you would have to nudge it to see the gas. It is still giving me the same raw gas smell after parking it. After returning I removed the air breather and noticed a lot of smoke rising from the secondaries and it was also very wet in the secondary barrels. It was also wet in the primary barrels but not as noticeable

how about a bad power valve in the carb
Had a bad power valve before and it ran very rich then. put in new power valve and the rich eye burning exhaust fumes went away. I don't think that's where the problem is
thanks, Pat

Did you maybe just put too much gas in during your trip ?? It was unusually warm over the weekend here and I filled up the tank ( a little too much ) and noticed the garage wreaked as well on my return...no leaks.. but my smell was from the BACK of the car. I figured some may have expanded out the vent during the ride... as there was a lot of pressure in the tank when I slowly unscrewed the cap...just a thought

no I have had that problem in the past. actually took it out and put half a tank in it about 2 weeks ago. didn't have the raw gas smell after that little trip. for some reason I thought the sightglasses being half full was correct, but now reading an earlier post if I didn't have sightglasses the bowls couldn't be higher than the bottom of the sight plug hole. boy this old age thing really does play hell with your memory. guess that's what happens when you leave the hobby for about 20yrs then return. thanks, Pat