C-3 327w/ 600 holley

[Grant]

I'm new to this so bear with me. I recently bought a 68 conv. It has a 327 with a 600 holley. It runs great until its a hot day and I'm at a light. When the temp gets around 190 it will stall when I take off. I was told it was vapor locking due to the headers so I installed a electric fuel pump just to see if that was it. It helped some I think, but it will still do it. When it does it I floor it and it will restart so I'm thinking it may be flooding. Has anyone ever had this happen?

[Wayne K.]

Re: C-3 327w/ 600 holley

Grant,

If the only way it will restart is to hold the pedal to the floor while cranking then I think your on the right track and you need to find out why it is flooding. I would get the car up to temp and someplace off the road let it idle until it stalls when you try to move out. If it stalls turn off the ignition and immediately open the hood and take the air cleaner off and look into the carb and see if there is any raw gas entering the main body. If there is you may have the float or floats set too high, could have a bad needle and seat, or leakage due to warped main body, metering block or plate, bad gaskets, etc. The combination of the accelerator pump shot and leakage could be enough to flood it out under those conditions.

Wayne

[Grant]

Re: C-3 327w/ 600 holley

Thanks Wayne for the info. I'll try that and see if it looks like it has raw gas. I should be able to smell it also. The thing that has me confussed is how good it runs one cold days or evenings. Then have a real hot day and it starts to act up.

[Wayne K.]

Re: C-3 327w/ 600 holley

Grant,

On hot days the gas is expanding enough or it could be boiling in the float bowls causing overflow into the engine. Lowering the float level may be the fix if that is the only problem.

Wayne

[G B.]

Re: C-3 327w/ 600 holley

I think your problem is percolation. The gas in the bowls is boiling over. Perhaps your exhaust cross-over in the intake below the carb is passing too much heat. Is the heat riser valve below the passenger exhaust manifold wired open? It should be for summer driving.

What intake manifold do you have? If it's one of those communist GM cast iron jobs with the exposed exhaust crossover passage just below the carb, then I'll bet that's your problem.

[Joe L.]

Re: C-3 327w/ 600 holley

Grant------

One other thing: I'd get rid of the headers. Headers are great for performance but bad for everything else. Corvette engine compartments get too hot as it is. Headers compound this problem many times over and create untold peripheral problems. I wouldn't use a set of headers on a Corvette if someone gave them to me. In fact, I wouldn't accept the best ones made as a gift.

[Grant Hile]

Re: C-3 327w/ 600 holley

I'll have to live with the headers and leg pipes for awhile so I hope some of the suggestions work. Thanks to all for all the help.

Grant

[John Walker]

Re: C-3 327w/ 600 holley

Grant; I put a 454 (big Block) with headers and undercar exhaust in my wife's 73 and after figureing out the timing and carb settings I do NOT have any problems with boiling gas up to at least 100 degrees F outside. Duke and Clem helped me with my problems, which by the way had caused heating, and now my wife's car is very driveable and trouble free. John