Vapor Lock

Ok so there have been a few bugs with my new ride. We got the mechanics squared away but with this horrendous Florida heat the fuel keeps getting too hot and the Holly Sniper goes crazy trying to use unusable fuel. Surely I’m not the only one facing this dilemma.

Oh yeah, good old vapor lock. Kids now days have no idea. I'd start with a heat wrap type material on the fuel line in the engine bay. Thermo-Tec is a good brand. If the fuel line is close to the exhaust, you will have to wrap it to the tank or reroute it. That's the most common solution. If that doesn't work, an electric fuel pump will help if you don't already have one. A plastic spacer under the carb can help if you have clearance.
After that it can get expensive. My electric fan will continue to run, after shutting down, until the sensor it the radiator cools. Have no heat wrap on the hoses. Never had a problem here in Phoenix. Went to a Chrome & Caffeine this morning but it was only 100 out. Next step can be an air gap manifold. Don't know enough about them to give any advice, but some guys swear by them. After that is fuel injection. Bigger $.
Love the idea and tech of F.I. but have not met a single person, of the hundred or so i've asked with aftermarket systems, that has not had a major problem in less than 2 years.

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So I got a new throttle cable. VERY NICE pedal finally. So by 7:30pm last night the temp was down to 90. Well, I wanted to do a night drive to see how the headlight light the road. They did great. Did slow driving faster driving. Stop and go driving. I even parked at a gas station with the engine off for 15 minutes to see it would hot start. No problems.    So 99 is vapor lock heat but apparently 90 is ok

I’m really hoping the insulation of the fuel line and throttle body will be enough to prevent vapor lock on the warm days we are willing to drive. 99/100 is not fun anyway.

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Phase one of heat shield operations is a success. I installed the throttle body spacer last week. So I dove the car to church today. We get out at noon. Near 100 degrees. I was fully aware that if the spacer didn’t make a difference I wouldn’t make it home. Well, I made it home no problem. Now to do the fuel line wrap and that should be extra insurance.

Phase two of heat shielding operations is underway. The Throttle body spacer helped a great deal but the fuel is still getting too hot.

So I’m replacing the aluminum fuel lines with braded rubber, adding heat shielding tubing over the new lines and adding a fuel cooler radiator up front.

I’m hoping this will put the problem to bed.

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Ok so, good, bad and good news. Lol. So, I replaced metal fuel lines for insulated braded rubber with additional heat shielding. I also installed the fuel cooler.

Went for a test drive in the heat of the day. 93 degrees or so. I did 55 miles on country road. LOVED IT LOVED IT!!  

Before the fuel cooler and heat shielding the darned thing was getting 7 mpg.  Today 54 miles and it took 4.7 gallons. So that’s like 11.5 mpg. Could be a tad better than that because the sniper had to reprogram itself and I don’t know how many miles that actually takes.

The bad news, it did vapor lock once.

But, good news…it was much milder in that it recovered quickly and didn’t happen again.

I’m thinking about upgrading to dual fans to lower the engine temp a bit. It stays at 200 right now which is not terrible but maybe lowering that 10 or 20 might ultimately fix it.

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Ok one last mod and if all this is not enough I’ll have to either convert to a cold air intake or install a hood scoop.

Anyway, I installed two shop vac hoses from the front grill to nearby the air cleaner both sides. On the initial test drive the water temp is down 20 degrees. Cool air is blowing on the throttle body and air cleaner while driving and it seems to make a difference.

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So, first road trip. Went with my motorcycle group from Tallahassee to Apalachacola and the car performed flawlessly. It was so cool cruising the Forrest and the coastline. Great day today and another tomorrow. Not a hint of vapor lock and averaging around 17mpg with the highest at 22. I’m a happy camper

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There was also a guy with a Cobra tha went with us.

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Great News and So Cool that you got to enjoy all your Hard Work !!!

Looks like a great time, and it was Nice of You to Let the Cobra tag along ;-)

Take Care,
Craig

WoW! What a nice ride! great work

Hi, im installing a 1/4" insulating gasket under my vac sec holley, also thinking of doing the same fresh air duct but with 3" inline blowers up front to force cool air over carb and air cleaner......

sky25t wrote:Hi, im installing a 1/4" insulating gasket under my vac sec holley, also thinking of doing the same fresh air duct but with 3" inline blowers up front to force cool air over carb and air cleaner......

Let me know how you like the electric fans. I may add that as well. I’ll probably rely on your testing and evaluation for the right fans. lol

Its a work in progress..... i will let you know.....
Its coming up to summer with around 100 on hot days.... goid testing time.... but work comes first so not sure when i will fit the gear.....