So I have been suffering from vapor lock--big heat saturation after shutting off the engine. Wrapped fuel line, relocated fuel filter, checked fuel pump. Everything is warm, not hot, to the touch.

What IS hot is the base of my 500 CFM Edelbrock, which is mounted on a Clifton 4BBL aluminum intake. I am not running coolant through the bottom of the intake.
Also added a 1/2" aluminum spacer, and still getting vapor lock.
Intake sits on closed off rear exhaust manifold in Dutra Dual modification.

So Here's The Question:
If I am getting vapor lock without running coolant through the intake, why is the intake heating an option, and if people do use the intake heating, why don't they get vapor lock?

Insights appreciated,
Joe

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Joe Hoppe

71 D100 225 Super Six 727 AT on 2008 Crown Vic CopCar frame

64 Valiant Wagon 225 904 AT 3:23 8.75"

Are you running real 100% gasoline or the almost gasoline stuff that is currently at most pumps in the midwest?

I think the pumps in my locale are currently all 15% alcohol except for a few premium pumps that are either 10% or the single station that has 100% gasoline at 93 octane.

I remember reading vapor lock is worse with higher alcohol contents but I don't know that to be a fact.

A lot of people use "vapour lock" to mean a lot of different hot-fuel-related things. In fact it means only one thing. So let's figure out what's actually happening here. Please describe the symptoms in detail.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

This is no longer an option for most people in the US and Canada.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Dan--

Good point.

So my symptoms are:
Car runs great
shut down engine for 10-30 minutes
car starts up again fine, but after approx. 5 minutes of driving, loses power. Engine eventually stops.
Rest for 10 minutes, car starts up again, but power loss is quicker.
Last two times I have been able to nurse it home by driving below 35 MPH
Engine temp. gauge reads approx 185--not overheating there.

What I have done to fix the problem:
Changed coil (old coil--Pertronix--felt hot to touch)
re-routed fuel line per article by Dan here on Slantsix.org
used DEI sheathing on fuel line from filter to carb
line is 3/8" injection fuel line
installed 1/2" aluminum spacer under carb
changed to metal fuel filter per article by Dan here on Slantsix.org
checked air filter
ran gas tank down to half full and filled with hopefully higher quality gas

Remaining symptoms:
Fuel line cool
Fuel filter cool
base of 500 CFM Edelbrock carburetor hot.

Next fix:
1/2" phenolic spacer ordered.

I think that's everything.

Still curious about coolant heating Clifford manifold. I had used the heating in the past, but it made the engine run too hot.

Thanks,
Joe

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Joe Hoppe

71 D100 225 Super Six 727 AT on 2008 Crown Vic CopCar frame

64 Valiant Wagon 225 904 AT 3:23 8.75"

It's a lot more accessible than you think. A lot of farm equipment doesn't like ethanol, so it's more accessible than folks think

https://www.pure-gas.org/

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1970 Barracuda 225 /6, 3spd on the floor, Blue/Blue

Aluminum transmits heat very effectively. Ditch the aluminum spacer and replace it by a phenolic one. Add a heat shield, sandwiched with thin gaskets; something like this.

Double-check your float level and your bowl vent adjustments.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks, Dan.
Your advice is always appreciated.

Joe

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Joe Hoppe

71 D100 225 Super Six 727 AT on 2008 Crown Vic CopCar frame

64 Valiant Wagon 225 904 AT 3:23 8.75"

Gladly. Also pay some attention to what's heating up the engine bay: the exhaust. Things under the hood will cool way down if you'll wrap at least the headpipes and perhaps also the manifolds with this.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

How did you get a Clifford intake manifold to seal against a stock exhaust manifold? Does the exhaust flapper valve on the manifold work correctly?

I would use the internal water passages on the Clifford to help maintain a consist heat through out the manifold. This will give you a consistent fuel mixture through out the manifold.

When I was running my Clifford I had a 1" water heated 4v spacer from a Ford FE and a 1/4" gasket from a 1969 396 Chevelle with a Holley. Strangely, parts stores usually had one on the shelf.

Kesteb--

The Clifford manifold isn't connected to the stock manifold. I have the top of the manifold welded shut and the front cut off as per the Dutra Dual modification.

Since I get vapor lock without any heated water in the manifold or spacer, I am wondering how people are able to effectively use water heating for fuel temp.

Sorry for the confusion,
Joe

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Joe Hoppe

71 D100 225 Super Six 727 AT on 2008 Crown Vic CopCar frame

64 Valiant Wagon 225 904 AT 3:23 8.75"

I'm still not convinced you have vapour lock. That term means the fuel pump and its input line get too hot, so the fuel boils (vaporizes) inside them, so the pump stops working because it's designed to pump liquid. I don't think that's what's happening in your case; it sounds more like the carburetor's getting too hot.

Nevertheless, to my previous to-do list I posted, I'd add: use a fuel filter with a 3rd nipple (vapour bleed with orifice). Orient the filter correctly, 3rd nipple up, and run a line from the 3rd nipple all the way back to the fuel tank vent. This way, when the pump-to-carb line and the fuel filter heat up on hot-engine shutdown (no more fan blowing air through the engine bay), the excess fuel pressure will safely bleed off back to the tank rather than forcing past the carb's inlet needle, overfilling the bowl, and flooding the intake manifold.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Seems like solid advice.

Joe

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Joe Hoppe

71 D100 225 Super Six 727 AT on 2008 Crown Vic CopCar frame

64 Valiant Wagon 225 904 AT 3:23 8.75"