Simple Remedies for Vapor lock and hard starting.

[FL SAAC]

Hopefully you will comprehend that by using my method will cause an anomaly resulting in spinning heads, foaming at the mouth, eyes rolling, finger pointing, crowd gathering, people speaking under their breathes and a very severe POINTS deduction.

But yes it will stop the fuel from atomizing and percolating. The car will work just fine.

Please don't let the attached picture distract you, its only Silky Johnson, Buc Nasty, Mr Beautiful also known as The Haters...

Exactly what I did, Tony. I didn't want it to be too obvious. The fuel pump line under the power steering has a slide on insulation as well as as about a food that runs next to the power steering pump. The 427 canister filter doesn't seem to create an issue.

[Bob Gaines]

Heater Hoses - It seems like a common routing for the heater hoses is to have them run right alongside or right over the top of the fuel log. I have tied the heater hoses to the Export Brace with black zip ties to lift the hoses up away from the fuel log as much as possible.

A solution on the spacers between the fuel log and the intake -- I removed the two intake manifold bolts that secure the fuel log and installed studs. I tightened the studs using the "double nut" method.  I then installed a spacer, the fuel log and a nut to secure. As Bob pointed out, if you try longer intake manifold bolts, they do not clear the intake manifold where the carbs sit and will not install.

Another step that is admittedly drastic is to install a louvered hood. I have no scientific data, but seems those louvers would really help get hot air out of the engine compartment.

This is a great thread.
Jeff

Good thinking with the stud idea.

[The Going Thing]

Heater Hoses - It seems like a common routing for the heater hoses is to have them run right alongside or right over the top of the fuel log. I have tied the heater hoses to the Export Brace with black zip ties to lift the hoses up away from the fuel log as much as possible.

A solution on the spacers between the fuel log and the intake -- I removed the two intake manifold bolts that secure the fuel log and installed studs. I tightened the studs using the "double nut" method.  I then installed a spacer, the fuel log and a nut to secure. As Bob pointed out, if you try longer intake manifold bolts, they do not clear the intake manifold where the carbs sit and will not install.

Another step that is admittedly drastic is to install a louvered hood. I have no scientific data, but seems those louvers would really help get hot air out of the engine compartment.

The louvered hood would be ideal. I presumed the hood scoop would help with keeping the heat out from under the hood. There seems to be cavitation at the firewall.
The double nut method would still allow heat transfer to the fuel log.  I used the spacer between the ear of the fuel log and intake and on the top between the bolt and washer and the ear of the log. The bolts will also transfer heat if not insulated from the log.
I started off with the simple changes and kept looking for other ways to "beat the heat".  I have no hard-start issues anymore or percolation.
I was just posting the newest addition to combat vapor lock.  The pump insulator.
An insulated fuel supply and carburetors goes a long way in the battle.

[Bob Gaines]

Heater Hoses - It seems like a common routing for the heater hoses is to have them run right alongside or right over the top of the fuel log. I have tied the heater hoses to the Export Brace with black zip ties to lift the hoses up away from the fuel log as much as possible.

A solution on the spacers between the fuel log and the intake -- I removed the two intake manifold bolts that secure the fuel log and installed studs. I tightened the studs using the "double nut" method.  I then installed a spacer, the fuel log and a nut to secure. As Bob pointed out, if you try longer intake manifold bolts, they do not clear the intake manifold where the carbs sit and will not install.

Another step that is admittedly drastic is to install a louvered hood. I have no scientific data, but seems those louvers would really help get hot air out of the engine compartment.

The louvered hood would be ideal. I presumed the hood scoop would help with keeping the heat out from under the hood. There seems to be cavitation at the firewall.
The double nut method would still allow heat transfer to the fuel log. I used the spacer between the ear of the fuel log and intake and on the top between the bolt and washer and the ear of the log. The bolts will also transfer heat if not insulated from the log.
I started off with the simple changes and kept looking for other ways to "beat the heat".  I have no hard-start issues anymore or percolation.
I was just posting the newest addition to combat vapor lock.  The pump insulator.
An insulated fuel supply and carburetors goes a long way in the battle.

Studs would seem to allow more room for appropriate isolating spacer .   You can always eliminate the tabs altogether as I mentioned.

[Drew Pojedinec]

Most of the stuff has been covered....

I wrote this a few years ago for when customers had heat soak issues.
It is certainly not the end all but it was meant to point folks in a direction, so a cut and past from my files.


Starting to get warm out around here. In prep for summer driving, a small primer on how to avoid fuel boiling in the carburetor on shut down. My "fuel percolation issues checklist"

I had this problem a lot in Southern GA. Part of the issue is me running whatever pump gas is available. Most of this is 10% Etoh junk. Sure sure people can say "well just buy pure gasoline." But I want my cars to be real street vehicles, I drive them everywhere. The only vehicles I own are carbureted, so it isn't an option to seek out special fuel, especially on 5-6 hour trips.

-Carb spacers. Edelbrock makes a 1/4inch spacer that is good. If you can go bigger, use the phenolic wood resin types, they are the best.

-exhaust crossover blocking. It isn't hard, just get some steel sheet jb welded in the exhaust crossover.

-try to shield the accelerator pump. If fuel in it expands it will push out the accelerator pump nozzle. I think in the 80's Ford addressed this issue by drilling a tiny tiny hole in the accelerator pump channel in the metering block which pushed the fuel back into the bowls. If you look at the location of the pump, it's pretty much a wide open heat sink on shut down. In my Galaxie, I run 2, 600cfm Holleys.... twice the fun! Would be just as bad with a double pumper.
This is less of an issue with the check ball type of pump and more a problem with the later umbrella seal style.

-Keep your timing as far advanced as feasible. Limit mechanical to your max and push the initial a lil further if you can. I regularly run 18 initial and 38 total on a "stockish" engine, my HP engine runs 22 initial, 32total, and it helps keep it cooler.

-Fuel line insulation and isolation, keep it away from anything hot. Best is for it to enter the engine bay and go directly to the carburetor.

-Electric fuel pumps. Insulating the fuel lines doesn't matter if the fuel goes into an engine mounted fuel pump. Have you ever felt how hot the fuel pump gets while the engine is running? Hot oil is splashing on the inside.... just trust me, it gets hot. This also makes fuel routing easier as you can keep it away from anything hot. I run -8 SS braided hose and it stays decently warm through all scenarios.

-Fuel regulation and control. With modern fuels, the are designed for sealed fuel injection, so being exposed isn't an issue. Of course we run carbs, they are wide open. This fuel expands and contracts, and I do not have the data to back it up, but I think the specific gravity is different than it used to be. On side hung floats I regulate to 4.5psi With center hung floats I regulate to 5.5psi. I have also found that the .097 needle valves are better at keeping control than the .110 that most new carbs come with. Now some folks might say this isn't appropriate for performance usage. Everyone knows fuel in a carb is about flow not pressure. Use a larger pump and hoses than needed and have a good regulator.... no problems. I'm in the under 600hp crowd and the Carter HP 4600 works great as a lift pump, very quiet and seems very sturdy. I use a QFT regulator with an Aeromotive gauge. (30-1803QFT and
Aeromotive Fuel Pressure Gauges 15632).

-Some folks suggest a return line. I have never used one, so I cannot comment. Thus far I haven't required one.

[JWH]

Just to clarify, the "double-nut" method I refer to in post #15 above concerns installing the studs.
> remove the two stock intake manifold bolts that attach the fuel log
> install two studs in their place and finger tighten
> spin a not onto the stud
> spin a second nut onto the stud and with a wrench, tighten top nut clockwise and the lower counter-clockwise so that they "lock" against each other.
> with the nuts "locked," you should be able to exert enough force on the top nut to tighten the stud in place in the head. This is to keep it from backing out over time.
> remove the nuts and install the spacer, fuel log, spacer and nut as recommended

[The Going Thing]

Bob, the tab elimination and getting the hot heater hoses off would be simple. You can find a repo fuel log for about 50.00.  Summit has spacers if that's your choice of routes. I did find the Phenolic spacers held up to the 32 Lbs torque spec fine.

[The Going Thing]

Just to clarify, the "double-nut" method I refer to in post #15 above concerns installing the studs.
> remove the two stock intake manifold bolts that attach the fuel log
> install two studs in their place and finger tighten
> spin a not onto the stud
> spin a second nut onto the stud and with a wrench, tighten top nut clockwise and the lower counter-clockwise so that they "lock" against each other.
> with the nuts "locked," you should be able to exert enough force on the top nut to tighten the stud in place in the head. This is to keep it from backing out over time.
> remove the nuts and install the spacer, fuel log, spacer and nut as recommended

I assume you may have bought some of the studded intake bolts that were used for the cars with shaker air cleaners.  If you isolated the studs with the phenolic washers on both sides it would be the same situation as the factory longer intake bolts with the wahers.