Need advice on how to correctly manage vapor lock

[Rentalman]

Good evening. I hope you all had a great 4th of July celebrating 250 glorious years of freedom! Yesterday I took the Scout out for a 35 mile drive putting it to the summer heat test. According to the speedo app I use, travel time was 1 hour 26 minutes. I live in the Inland Empire in So Cal. The summer time heat is hot. The temps yesterday were 87 to 93 degrees. The route was partial traffic averaging 22 mph for 20 minutes with stop-lights and idling. After that the road opened up to 45 - 60 mph for another 20 miles with fewer stop-lights. I got to my destination, Diamond Valley Lake and drove back home. The rural route again was 45 - 60 mph, then back into stoplight traffic averaging 22 mph. I was about 2 miles from home and I could tell the engine would was starving for fuel. It died twice and restarted each time. I put the TF727 in 2nd gear and got the rest of the way home and parked it in the garage. I used my infra red thermal gun to measure the heat. The manifold was 211 degrees, lower radiator hose into water pump was 180 degrees. I always check my hub heat and they were 130 degrees. I let it sit for a few minutes. When I went to restart it, the solenoid spun but did not engage the flywheel. On the firewall I have a Ford Solenoid. On the second attemp to start, it fired right over. I raised the rpm's slightly and it was not missing a beat. I believe I experienced vapor lock and heat soak. Most of you have helped me along with other issues. If not familiar with my Scout it is a 1974. Balanced and blue printed 345, ported and polished heads, Isky spit duration cam, Stans ceramic coated headers, Holley 0-7448 2300 carb with Pertonics III ignition and coil. Power is sent through a TF727 to a Dana 44 with 4.10 gears. My headers are wraped from the collectors back to avoid heating the deep TF727 oil pan, the exhaust is 2 into 1 going around the tranni pan. I have a stock radiator with OEM fan shroud and 6 metal blade fan with clutch. The hard fuel line into the engine bay is wraped as many of the engine bay wires are wraped in DEI foil heat wrap along with the trani hard lines to the radiator. From the mechanical fuel pump, fuel lines to fuel filter and fuel line to carb they are not wraped along with the hi torque starter. I need to wrap those soon. The exhaust gets routed on the driver side. The fuel line, wiring, vapor line to charcoal canister and axle vent lines are all routed on the passenger side to avoid exhaust heat.

I've researched Youtube and the internet. The common fix people are doing on these vintage vehicles are replacing the fuel filter with is a Wix 33040 three port filter that has 1/4" vapor line.

Would this be the correct fix for the IH345? I would mount the filter so the vent line is vertical between the mechanical fuel pump and carb, make a hardline to follow my fuel line back to the tank. I could eighter add a brass T into one of the 5/16" liquid/vapor separator lines that feed back into the fuel tank or I could tap into the 1/2" vent hose line that comes off the CPT fuel fill pipe that goes into the fuel tank. Sorry for being long winded. As usual I appreciate all of your help.

 

[Scoutboy74]

Do you have the proper heat shield spacer gasket that extends beneath the carb fuel bowl?

 

[Rentalman]

Yes I do have the correct carb gasket.

 

[Winchested]

Was the fuel filter empty? Could you noticeable see the fuel boiling in a clear filter? Is this in a new clean tank with a clean pick up sock?

I never had fuel boiling issues or vapor lock, I had dieseling run on issues after shutting down. I only ever run 87 because these engines don't warrant any better gas then that if you set your timing correctly.

I ran a phenoilic spacer eventually with the good carb gasket. Never could get it completely stopped.

The only other thing that could have been done weld closed the exhaust crossover on the intake that super heats the carb.

Best $600 bucks ever spent was converting to DIY junk yard Hamilton fuel injection.

 

[Rentalman]

Unfortunately I have a metal fuel filter. I do have a site glass on the carb. Fuel was at the correct level in the carb. Now this could have corrected its self after I got it restarted and drove home in 2nd gear the last 2 miles. When I was building this Scout I sent the fuel tank out to a fuel tank repair shop. They sandblasted inside and out. Then they applied Tank ReNu a patented process that gets baked on. I also have a new fuel pick up and sock. I run the recomended 2-barrel gasket. What size is your phenoilic spacer. I've read that is something to do to get the carb off of the hot manifold. I run the stock metal air cleaner. I'm not sure how much room I have for one under the hood.

I took the Scout out for a short 5 mile drive this morning. It ran great. Temps on the lower thermostat housing were 205 deg and above 185 deg. Lower radiator hose to water pump 165 degrees. The engine fires quickly and runs strong. Never no dieseling when I shut it off. I use Chevron 87 gas.

How do you like the Hamilton Fuel Injection? I've thought of the Sniper too. I read alot of mixed reviews. I think that all comes down to have somebody who knows how to map it correctly. I don't trust the computer being in the Sniper its self with the engine bay heat. Heck, when I video my bass fishing trips on hot days with my GoPro, it shuts down from heat all the time. My Scout II and 800B both have carbs. I was priding myself that I could keep these running on carbs. Maybe all that chest beating isn't worth it...LOL

 

[FDChappie]

Suggestion, get a clear plastic fuel filter installed and look for bubbles while running. I'm guessing there is a small air leak between the pump and tank.

 

[Rentalman]

Hi FDChappie,

I think I figured out the problem. My fuel bowl float was adjusted to low. Let me know if this sounds like the culprit. When I got my Holley 0-7448 2300, it is the one with the site glass for the fuel bowl. The instructions that came with it were for the threaded site hole plug. This morning after my five mile drive I looked at my fuel level in the bowl. It was about 1/8" down from the bottom edge had it been the plug type (still to low). I always adjusted it in this matter due to the instructions I received with the carb. After researching on the internet, the site glass bowl gets measured half way to slightly under halh on the site glass. So with Saturdays 87 - 93 deg temps, 1 hour and 20 min drive in partial stop and go conditions with wide open stretches to go 45 - 60 mph and back home in stop and go traffic. I'm thinking with not the correct amount of fuel in the bowl it may have started to boil. Once I got it re-started after it stalled/died a couple of times and put it in second gear, it was getting plenty of fuel to keep running to get me home that last two miles. Included is a pic of my new fuel bowl level. What are your thoughts on this? I recenlty purchased some of those clear plastic fuel filters. Later tonight or tomorrow I will install one so I can check for bubbles and fuel. Thanks for your input as always.