Technical Fuel tank insulated coating ?

I'm building a 37 Ford and purchased a new fuel tank for it. I want to prevent the kind of issues I'm having with my 66 Mustang with today's alcohol mix fuels in hot weather. When the ambient temperature rises to 95 or more (at 6000 feet altitude) I experience vapor lock with the Mustang and on one occasion (at 105 degrees) the gas cap was whistling. Since the new tank for the 37 is bare steel right now I want to spray some kind of heat insulation coating on it to keep pavement heat and exhaust heat away from my fuel. Has anyone done this kind of thing with success and what product was used ??

 

I have not done it myself, but I have heard people use Lizard Skin with good results for heat insulation. On my Buick I used heat wrap on the exhaust where it was close to my gas tank. A return line from the pump back to the tank will also help with vapor lock, by bringing fresh cool fuel forward continuously.

 

Electric fuel pump with return line to tank will solve your problem.

 

What he said ^^^^^^^^^^......... If you look at how electric pumps are done, use one thats an "in tank" pump. Don't use one that doesn't have a return line.
The regulator can be mounted under the car slightly ahead of the tank and then you only have to run the return line from it instead of all the way from up by the carburetor.

 

So..... back to the OP's question: Has anyone insulated a gas tank?
I didn't see ONE line in his post about what fuel to use, what pump to use, what color your eyes are! @BJR is the only person that responded to the question!
Let the shitshow begin.....

 

I get ya, but I’d wonder when vapor lock occurs, is it in the tank, or downstream in the line? I’m thinking more down stream, than origin.

 

Insulating the tank is a waste of time and money. Won't do anything to prevent vapor lock.

 

Had clothes pins on my 52 Ford for vaporlock

 

Fuel tanks don't get hot, well, ambient temp....... If exhaust is close to the tank, wrap it a foot or two. Where's that carb sitting? =on top of a iron furnace......Insulate lines from pump to carb, and use a phenolic spacer/ heat shield, etc........

 

If the gas cap was whistling, it was trying to vent. Sounds like you need a better vented cap or a separate vent on the tank….

 

Well, I guess I am the only one who did it???? My 55 Olds was so low, that on real hot days, driving on even hotter asphalt, it would vapor lock. I tried a few things, but the outcome was, the tank got so hot, you could hear the gas percolating inside the tank.
I just used the same insulation I used on the floor, aluminum backed foam. Held in place with the gas tank straps. Fixed the problem.
Ugly, but it worked.

 

chopolds: It would have been interesting to find out the temperature of your gas tank.
Can't argue with your success.

 

fuel tanks do get hot !! Perculating gas tank is the problem I've had with the Mustang - and am trying to prevent with the 37. Today's craptastic gasoline boils at 137 degrees F - at sea level -- and I'm at 6000 feet. If its 105 degrees F outside, an asphalt road or parking lot is hot enough to cause burns - which is over that 137 boiling point. That's why my gas cap was whistleing - and why I have issues with vapor lock. An electric pump is an extra level of complication I would rather avoid. So far the only answer to my question was Lizard Skin -- with the opposite opinion being don't bother.

 

Its pretty logical that the same heat that is reflecting towards the gas tank is also reflecting towards the gas line traveling forward to the engine. That may also be getting heat from the cars floorpan if its as hot as the gas tank is supposed to be. Then maybe a little heat added by a nearby exhaust pipe, and the heat added by close proximity to the engine and finally the heat absorbed while sitting in the carburetor bowl. I also have to wonder why ALL the older cars operating at 6000 ft on a 105 degree day do not have the fuel in their tanks percolating just like yours. Even being lowered, there are plenty of others that are lowered. As for the whistling gas tank, I'd suspect that it might be somewhat clogged if it whistles when venting. You can spray Lizard Skin on your 35s tank as a precaution, but I have my doubts that the gas tank being too hot is the cause of your problems. I as well as others suggested what we thought were the most logical options to insure that you don't have a problem. If you wish to disregard those suggestions because they didn't directly answer your question, thats your choice. I wish you well in resolving your problem.

 

I wonder how many "modern" cars have this problem.
Would fuel injection cars have this issue?

 

Probably not. They have a return line to the tank.

 

"Probably not. They have a return line to the tank."
Then, I bet a fuel filter with a return line to the tank would solve the problem

 

Here's a good video on how this problem was solved.
(1) Holley & Edelbrock Fuel Bypass System: Return Line to Tank Connection (EASY & SIMPLIFIED) - YouTube

If you Google "Bypass Fuel Filter" items like this appear:
Amazon.com: FRAM G3499 In-Line Fuel Filter : Automotive

Wrap your tank with heat insulation material.
heat shield insulation - Search (bing.com)
and
Amazon.com: Design Engineering 010408 Cool-Tape Self-Adhesive Heat Reflective Tape, 1.5" x 15' Roll, SILVER : Industrial & Scientific

 

One other thing came to mind. If a tank is building pressure ..........enough so that it is trying to relieve that pressure by venting.............isn't it likely that the pressure would also be pushing fuel out the bottom of the tank and forward thru the fuel line ? A lack of fuel could be due to insufficient venting which might also produce a whistling sound when pressure was inside due to expansion from the warming liquid.
Just a random thought.............

 

https://redirect.viglink.com/?forma...m: FRAM G3499 In-Line Fuel Filter : Automotiv

With the bypass filter......I guess you still need an electric fuel pump ??!
Tanx
6sally6

 

[QUOTE=With the bypass filter......I guess you still need an electric fuel pump ??!
Tanx
Pontiac used a bypass filter between a manual pump and the carbs. Don't know why you would need an electric pump.

 

Modern cars don't have vapor lock because fuel injection runs at much higher pressure. Higher pressure means higher vapor point.

 

@studebakerhawk Do you have the room and means to mount a heat shield about 1" to 1 1/2" below the tank? This would allow an air space between heat sources and the tank. Think of the heat shields used behind a wood stove, or what is used in proximity of a catalytic converter.

 

Teapots whistle when heated right .... heat is definitely the problem, not a lack of venting because the car runs normal when the ambient temp is under 95 - and the engine never boils over, I'm pretty sure the root of the problem is that the tank gets heated to near or in one instance over the boiling point of the fuel - and then any additional heat that the steel line picks up along the way causes vapor lock. I'm hoping to prevent this with my 37 build without resorting to using an electric pump -- I would have gone with a holley sniper setup instead of a 4 barrel if I wanted an electric pump. Later this week when the holiday dust settles I'm going to call lizard skin and talk about the product with them. Thanks everybody !

 

oh yeah -- and with a normal fuel pump the steel line is under suction which lowers the point where fuel would turn to vapor. I totally get that an in tank pump like a modern car would absolutely prevent vapor lock - but I'm trying to keep things simple -- and I might just be worried about nothing - just because my Mustang with its big flat bottomed tank facing the hot pavement vapor locks does not mean my 37 will --- Mom's 37 tudor with 302 - C4 was her daily driver in Tucson AZ and never vapor locked -- but then that was prior to alcohol mix fuels too. If it wasn't a long drive to get non alcoholic fuel I'd just get real gas.

 

I have a modern OT Ford chassis under my '56 F-100. One thing I like about this donor chassis is that it has a plastic gas tank and submerged fuel pump. Since the tank runs along the inside of the driver's frame rail, it has an aluminum heat barrier on one side to deflect any exhaust heat. If the Ford engineers spent the big bucks to R&D this setup on this super basic fleet vehicle with the factory exhaust system being over 10" away at it's closest, I'm sure there's a good reason for it.

Check into DEI products

 

We used to spray the tanks in early Porsche 911s with Wurth SKS, which is similar to bed liner. It is done more for abrasion resistance than insulation but I'm sure there is some insulating factor. Lizard Skin makes a ceramic spray that is similar to SKS and would probably work better for your idea. Having said that, I doubt it will cure your problem as vapor lock usually happens in metal fuel lines, not the tank.

 

Hi Stude,

You haven't said what you plan for your fuel system. If carburetor/s, then you do not need a high pressure return line back to the tank, a simple inline pressure regulator after an inline electric pump is fine. Strombergs like a low 1 1/2 to 2 1/2 psi at the carbs so even the electric pump can have a low PSI outlet. I think Holley work well with about 4 1/2 PSI. I like to put the regulator close to the carbs on my flathead with Strombergs.

Insulating the bottom of the 37 tank will keep the gas cooler. Run your fuel line away from heat sources and insulate where not possible.

Even if you have a FI system, the gas can boil. I had this situation with my K100RS BMW motorcycle. The factory added a heat shield on the bottom of the tank which helps substantially in keeping the hot motor from adding heat to the tank. However the FI return line to the tank is fairly long and in the heated space under the tank and above and close to the motor. After I added pipe insulation to these fuel lines, I stopped getting boiling.

Glenn

 

Hello,

If the tank is sitting on your table, take it to a commercial undercoating spray dealer for full coverage. Some of those pickup bed insulated liner spray places still exist in your area and they may give you some extra coverage of your tank. But, make sure you have room to put the tank with extra size outside thickness to fit back in place.

if everything else underneath is finished, a custom sprayed black coating will give your undercarriage some added styling and detailing. Big factory sedans had variations of undercoating on the tank and parts of the car. A professional undercoating spray business will give you a better insulating coating of the the stuff that surpasses anything a factory throws in place.

We had a 58 black Impala, a 65 El Camino and a couple of other cars that got the full undercoating spray from a commercial dealer. He used a cleaner first, then sprayed on the black undercoating with a couple of passes. It was solid, thicker than normal and when we hit the tank, it sounded like a thud, not a ping. Plus, being near the salt water environment is always a challenge.

Sometimes it is just a car wash away, but things underneath do not get the full spray unless one goes to a spray booth for full water wash, underneath. Rust works everyday and night if the salt spray is not cleaned off. If and when you drive your car through salt water, everything gets its coating and rust is the champion if not cleaned off. Boat launchings, puddles of high tide water in parking lots, and even roadways covered with salt water on extreme "King Tides," that are high tides, higher than normal.

So, the layers of professional undercoating did the thicker protection coverage for us. That is much better than buying spray cans of the “undercoating” stuff. Most factories charge for undercoating or the undercoating layer is minimal at best.

Jnaki

Our current daily drivers came with factory undercoating and yes, minimal at best. But the rest of the car is somewhat insulated inside and the noise factor is not noticeable as an old hot rod. The tank does have a minimal spray coating, but it is not like the thicker undercoating we got back in the old hot rod sedan days… YRMV