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77 F150 4x4 351M Vapor lock problem

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Old 05-05-2015, 01:37 PM
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77 F150 4x4 351M Vapor lock problem

Ok Guys, I have an issue with vapor locking. Truck has a stock 351M 2 barrel with EGR below carb.
It does it when it gets over 90 outside. I have changed fuel line to rubber and heat wrapped it. Changed thermostat to 160.
Any Ideas?
 
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Old 05-05-2015, 01:51 PM
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Put a heat shield between the EGR spacer & carb, and use a thick phenolic gasket?
 
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Old 05-05-2015, 01:55 PM
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Do you know where to get a heat shield for a 2 barrel?
 
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Old 05-05-2015, 02:07 PM
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Hmm ... now that you mention it, I don't know of a sheet-metal radiative heat shield, but there are spacer gaskets available that some people report have helped them:


http://www.summitracing.com/parts/fel-60529
http://www.summitracing.com/parts/hly-17-72
 
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Old 05-05-2015, 03:41 PM
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Thanks for the help. Do you know if the Motorcraft 2150 has the same footprint as the holley 2 barrel?
 
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Old 05-05-2015, 04:23 PM
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It's got the same bolt pattern and bore spacing; there are some differences with vacuum passages compared to the Holley 2300 that can lead to vacuum leaks if the gasket doesn't completely cover the footprint of the carb around the edges, but those two items are ones that I've seen people report on forums worked for them without problems.
 
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Old 05-05-2015, 04:29 PM
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Or you can try the cheap way. Put some wooden clothes pins on the metal fuel line.Sounds crazy but it honestly does work.
 
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Old 05-05-2015, 05:43 PM
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I have a small imperial cooler on mine fuel line, works fantastic!





 
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Old 05-05-2015, 06:11 PM
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Gosh I cannot type. Ugh
 
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Old 05-05-2015, 06:19 PM
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Gator I have gotten rid of the metal lines Thanks I have heard that before though.
Dmccorckle that does not sound like a bad idea. I am going to try the spacer first and than make a heat shield if the spacer doesn't work. That will be the next option after that. Thanks for the help guys all great ideas!!
 
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Old 05-05-2015, 06:58 PM
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Working on reducing heat around the carb may help... but vapor lock could be up stream. The suction side of the fuel pump near the heat of the engine is a trouble spot. On an '47 Power Wagon, if it heat soaked after shutdown I would literally have to hose that area down with cool water to re-start.

Making sure restriction is low as possible on the suction side may help (3/8" fuel pickup, clean fuel sock, clean fuel lines, good tank vent, good rubber hoses). The most effective fix is adding a rear mounted electric fuel pump. An electric fuel pump fixed the Power Wagon and also my Dent.
 
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