Vapor Lock

[Jack C.]

Besides letting her cool down, if all else is done correctly, is there anything one can do to help prevent or minimize it?

[Michael G.]

Re: Vapor Lock

Jack, Try to find the point where the heat is being transferred. The fuel line from pump to carb may be too close to exhaust. Or the intake manifold may be heating the carb. Both can be solved by insulators but will alter the factory appearance. If your set-up is not normally prone to vapor lock, you may just need to adjust the fuel line routing a bit.

[Jack C.]

Re: Vapor Lock

I know the carbs were hot. I sat idling while two aiplanes gased up yesterday. Stalled out and had to let her cool down. 20 minutes later it started right up. What type of insulators?

[Scott S.]

Re: Vapor Lock

Jack, i would check your fuel pump pressure. I experienced this problem on many NCRS road tours. One time I blocked one lane of the Ambassador Bridge on a Friday night. Many unhappy campers behind me! Found a weak/lazy valve in my fuel pump.
Scott Sinclair

[Michael G.]

Re: Vapor Lock

I notice you use the plural (carbs). I didn't know you had the tri-power. For the four barrel we would get a thicker (insulating) gasket for the carb-to-manifold which would reduce the heat transfer. Not sure if available for the 3/2s, but I would think so. I would still check for a heat problem with the fuel lines as this was always more common a problem. What engine temps are you at when this occurs? Normal, above normal?

[Jack C.]

Re: Vapor Lock

I guess I pulled into the airport about 180 degrees but sat idling for maybe less ten minutes. The gage was starting to creep up and then the stall. The air cleaner lid was almost too hot to handle. I would almost have to bet the gas in the carbs were begining to boil.

[Clem Z.]

Re: Vapor Lock

I guess I pulled into the airport about 180 degrees but sat idling for maybe less ten minutes. The gage was starting to creep up and then the stall. The air cleaner lid was almost too hot to handle. I would almost have to bet the gas in the carbs were begining to boil.

aluminum intake ?? block the heat riser crossovers between the heads and the intake and take the spring off of the heat riser valve so it stays open

[Michael G.]

Re: Vapor Lock

The early Sharks with monster motors like yours are known to be real "cookers". Some changes were made in the early 70s to rectify this, but mainly revolve around the drafting of air up into the radiator and only aided when in motion. I dont know the specs on the normal operating temperature of the 427, but at 180, your fan might not be enough to cool that beast down while standing still. Corvette Enthusiast had run some articles in the past 4-6 months (I dont have them with me) about cooling issues. Scott had a good point you might want to ckeck. You didn't mention if this situation is something new to your vehicle or common occurance.

[Jack C.]

Re: Vapor Lock

Yes, it is the aluminum intake and this was the first time I let it sit there and idle longer than I should. Thanks for the suggestions.