I am determined to resolve me heat soak problems before the weather gets really hot again. I am considering making a heat shield based on the templates in this thread:

http://www.slantsix.org/forum/viewtopic ... d&start=60

Alternatively, a member on forabodies has suggested

"get a metal fuel filter with a return line to vent the vapors back to the fuel tank. You will have to run a return line and get it back into the tank. Depending on your sending unit, you may already be set up for it. You do that and your problems should end. Vapor will still be able to get through the line back to the tank and you wont have heat soak"

I think this is the type of filter mentioned:

http://www.2040-parts.com/mopar-chrysle ... m-i468237/

Has anyone done this vented fuel filter modification? I have a '72 Scamp, does anyone have advice how I would run the return line to vent it to the tank? Can I use the charcoal canister for this?

Any thoughts which modification would be most likely to solve my heat soak problems?

I dont know what causing your vapor lock,,,,,but I would go after that before spending on the vented fuel filter thing.

Recirculating fuel ala EFI return lines actually makes the fuel hotter.

Heat shields can be really good

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Yeah....Im the one who destroyed this rare, vintage automobile.....

My problem is that the car is hard to restart in hot weather if I turn engine off and try to restart in about 10-15 minutes. I think the gas is boiling away in carb while it sits. So I'm calling it heat soak not vapor lock. I've heard both of my options that I mentioned are potential solutions. To be honest I'm not clear why venting the fuel filter helps prevent the fuel from boiling.

You're right, what you are experiencing is not vapour lock, it is percolation (fuel boiling in the underhood line and filter) under heat soak conditions. Do the Fuel line mod. A 3-nipple fuel filter as described there is not a fuel return à la EFI, it is a vapour bleed that can help quite a lot to alleviate percolation.

Carburetor heat shields can also help, but they're more hassle to fabricate than the fuel line mod, so I treat them as a second step if necessary.

Also make sure your manifold heat control valve is both present and free (flapper not missing, valve not stuck in heat-on position) and see that your carb is in top condition; the '70-'73 Holley 1920s are particularly prone to hot start/hot idle issues.

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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 for your reply, Dan. I don't mean to be dense but can you elaborate on your instructions:

"the 3rd is ¼" and has an 0.060" orifice to prevent bleeding off useful fuel pressure. You run a new vapour hose from that 3rd fitting all the way back to the fuel tank."

How/where do I connect the vapor hose to the fuel tank? Do I use fuel injection hose again or steel lines?

You can use hardline (steel, Cunifer or its less expensive equivalent NiCopp with a length of flexible hose at each end. At the other end you can tee into the existing fuel tank vent line.

Which reminds me, your charcoal canister is probably a couple of decades past due for replacement. They don't last forever, and when they (and their purge valve) deteriorate, one result is poor hot starts and hot idling.

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

I didn't know the charcoal canisters were still available?

Still available from Mopar?

As per the linked article!

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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 for the link. I will replace my canister and do the fuel line mod with vented fuel filter. Maybe I won't have to build a heat shield.

If I vent the 3-nipple fuel filter into the gas tank vent line, is there a chance liquid fuel will end up in my charcoal canister?

Not if the fuel tank vent lines and valves, etc. are in good shape.

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

The charcoal/vapor canisters listed in the article no longer appear to be available. The mopar part # and standard part #s are out of stock everywhere. My two local part stores also list them as discontinued. I have a '72, so my original canister has 4 ports.

Is this a suitable unit to use? Napa # 229844 ($184 - Ouch!)

http://www.napaonline.com/Catalog/Catal ... 0374712396

Are there other known canisters that would work?

Good info on the discontinuation. Yep, that NAPA unit will work fine, and it even has a built-in purge valve which is extra convenient. Charcoal cans have always been very expensive items. Fortunately they only need replacing every few decades! What application did you use to look up that number?

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

Believe it or not, I searched the 300+ vapor canisters on napaonline.com until I found the 12 or so that looked like they might work. Then, I called my local NAPA to determine that of those I identified, there was only one 4-port and one 3-port vapor canister still available.

The 3-port # is 220150.

I have no idea what the original application was for either. Somebody might be able to do a reverse look-up....

That's dedication!

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