Fuel Line Heat Shield and Cozplay

bnz84

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I have headers and was having a few summer time under hood heat issues. It was pretty obvious a little heat protection for the fuel lines was in order so I got this fiberglass wrap and pulled the lines apart. I needed to change some filters and old hose pieces so it was a good time to adjust the routing and bend up some new pieces. But before I got smelly and flammable I was thinking about how to add insulation without unhooking everything and I remembered using Crayola Model Magic foam with my kids years ago. Its kind of like playdoh in how its used it but it is a very lightweight foam and dries flexible. I believe it is Polyvinyl Alcohol and a few other things. I’ve since used this to quiet vibrations, make feet that prevent scratches, make flexible gaskets, and a test mold for a custom tweeter pod. I didn’t really take it serious because of all the bright colors and how lightweight it was. Come to find out it’s a big hit in the cosplay world and is known as Foam Clay that is mostly used for costume creation. Think light weight fake horns and masks and body armor. I bought some in black from Michaels to see if it could insulate and withstand fuel. Once dried (its water soluble) it shrinks a bit but a 1/4 thick pancake stopped my heat gun from heating my fingers and it did not melt. When I put the gun about 1” from it and let it go about 60 sec it did start to brown. Also it did not dissolve when I painted on gas and lacquer thinner. Once dry it can be sanded and painted but don’t count on a smooth surface. To get that you need to smooth it with a wet finger before it dries. Like caulk. So on the fuel lines it went. I was covering it with the fiberglass wrap so didn’t need to be perfect. I roughly formed it with a cut in half piece of clear tubing and once dry sanded it with a dremmel tool. I sanded through in a few places but whatever. Pics follow. The big test will be summer but so far so far no fuel heat issues. No I did not take the temp of the fuel before and after but the heat gun test convinced me it had a benefit. Is this an amazing fix? Probably not. Probably the heat shield next to my headers did everything I needed but this stuff is good to keep in mind for things that need cushion, need custom shape, need a shield from heat. It is not expensive, and if nothing else the kids can make Spok ears.

And Happy Friday! Next up is to use beer can heat shielding!

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LeBaron1973

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According to crayola's safety website do not use to make any objects put near to a heat source etc. So it may not be a good idea - be a shame to lose your car if the fuel lines began to leak and affected the product you used.

Source, crayola website craft safety.
 

CBODY67

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Keeping the fuel cooler might start in the fuel tank itself. I suspect it will absorb all kinds of heat radiating from the road surfaces. Which might make the case for a silver coating on the tank rather than factory undercoat (black)?

One of the first uses of ThermoTec wrap was for fuel lines in the underhood area, BUT many people started to wrap their headers in it instead. If done properly, it can look pretty good. That can have two affects. One is to keep heat radiation from the header tubes to a minimum and (two) also keep more heat IN the header for possibly better flow to the back? After the header wraps started to appear, ThermoTec came up with a kit just for that. There are probably some competitors for ThermoTec at this time, so shop around. It should be a better long-term solution rather than what you now have.

Just some thoughts,
CBODY67
 

bnz84

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I appreciate trying to protect each other from ourselves. Its not hard to get into a project but miss the bigger picture. But in this case it was very important heat and solvents wouldn't give me problems. So I did look it up because it didn't seem like a robust product. The Crayola stuff doesn't really talk about its ingredients and yes warns you about everything. Kids bring out the worst in layers! I didn't use the Crayola stuff. The stuff I used I suspect is very close and the MSDS is poly vinyl alcohol which gets good reviews on heat resistance and flammability. But I was convinced to test it myself when I saw this video where they try to light it on fire and it just blackens. Tried it with a heat gun and I was sold. Plus my fiberglass cover should help even more. My only concern was what its like over time and after 3 months my test pieces got more brittle but did not dry up or change form. Actually it does well enough that I'm a bit concerned about cool weather condensation and rust. But nicopp is pretty good with that so.... Yeah header wrap would help everything instead of treating each thing individually. But this was just a quick low cost experiment. If this doesn't help when its 98 I might go that direction but my headers are bit crusty already. Definitely on my next set I will address this probably with ceramic coating. Its funny I never had this problem before I sealed up all my air leaks around the radiator. The engine is doing better than ever temp wise, just the under hood ambient temps have risen.
 

CBODY67

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I'm not against any type of innovations, but anything with the word "alcohol" in its name tends to imply a certain degree (usually higher) of flammability (including what's imbibed by humans or vehicles) that can be concerning. Either from ignitability OR evaporation of items from the base material that is added onto something for whatever reasons, typically.

The issue with gasoline is that as it becomes more evaporative (which aids atomization in the carb/injectors), it might also result in other "handling" issues. Which also has related to issues relating to ambient temperatures when the vehicle is used.

From what I've observed (your observations might vary, which I respect), it's not an issue of heat generation under the hood, it can be more of an airflow issue under the hood and rearward of the engine assy.

In the middle '70s, I was using our '66 Newport for my daily-use main vehicle. The existing OEM-brand fan clutch was needed to be replaced. At that time, flex fans had come into existence and seemed to be a better alternative. So I got one of the Flex-A-Lite stainless steel replacements, along with the needed spacers for its correct relationship to the fan shroud. Got it all installed and proud of what I was doing (especially not having to worry about a failed fan clutch again!). On first drive, the fan sounds were obvious. Even with the 2.76 rear axle ratio, by the time I got to 60mph on the freeway, it sounded like an airplane that was poised to take off. Altering the spacer length made no significant difference. BUT, even after 70mph driving for over an hour in 90+ degree Texas summer temps, at the end of my drive, I could pull the air cleaner off and NOT have to worry about grabbing and HOLDING it as the air cleaner metal was cooler than the outside temps! The whole underhood area though it was only about 70 degrees, before it was driven any at all. THAT impressed me and was an indicator of just how much more air was going across the engine. NO worries about overheating (which was not an issue anyway). Even though the fan was apparently supplying an additional "pull" to move the car on the freeway, I suspected, there was NO fuel economy increases. Or any power increases as the air cleaner shorkel was directly in the air flow through the radiator.

End result, I took it off and reluctantly got a normal OEM-style fan clutch and drove in silence again. Taking care to remove the air cleaner (when needed), again.

We all tend to go through these "I'm going to fix it better than the factory did" phases, by observation. Some more than others, it seems, but we all want better solutions in many cases. Nothing wrong with that, just that when it doesn't work out, it becomes a "learning experience" of sorts. Which might lead to a deeper investigation into what didn't happen as we suspected it might . . . which can be good, in the long run. BUT it can also lead to an appreciation of how the factory engineers did things WITHIN a specified budget to make things as good as they might end up. Might some enhancements be made? Usually so, to better fit our particular situations before or after particular modifications/changes. What is used in these situations can be the result of what is easily-available and cost-effective at the time, for us.

Thanks for keeping us advised of your progress.

Enjoy!
CBODY67
 

bnz84

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Yes, its almost fun to work this out when its not your daily driver. But last summer I did suffer anxiety when in stop and go traffic because probably 50% of the time the car would not restart cleanly after it was turned off (or a stall). This all warrants another thread and relates to tuning also but I suspect not many on this forum have my particular problem. The non-factory addition here is the uncoated headers which is made worse by huge metal heat sink of an air cleaner that covers everything fuel/air related on the top end. Even good fan cfm would have trouble getting to the carbs. I've been reading the B body forums to commiserate and look for solutions. Temps at speed are not an issue its the idle and stop-and-go that's a problem. Short of cutting louvers I decided to let it be and concentrate on the air/fuel temps and see if I can bring them down. I suppose I could do the taxi cab hood pop:) I'm trying a few things not covered in this thread and even have a plan for fresh air intake (maybe). Definitely looking at the factory options of the time but most are aimed at non-headered engine temps at speed. Mine air under hood temps at idle. I have certainly focused on my current fan too. Its a non clutch 7 blade and moves a ton of air. But if todays tech can improve that I'm open. Insulating the fuel line was a no brainer for me but before I do too much I'm going to get some under hood probes to see what reality is. And therefore if my attempts are having any effect. I'll post results. There are a ton of helpful threads and people here, I would like to be one of them even if its a "I wasted time doing..." thread. thnx
 

CBODY67

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Rather than the taxi hood issue, which I first saw on later-60s 390 Mustangs (high speed overheat?), you might just remove the weatherstrip at the rear of the hood or on the front edge of the cowl. Might affect the same results without any real cosmetic differences?

Enjoy!
CBODY67
 

bnz84

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Old thread but as a follow up all is well with my heat shield foam and fiberglass shielding. No fires, no dissolving. I tested both before trying this. It did get a little more brittle and I had to make a new junction cover when I broke one while removing it. The shielding by itself did not solve my heat issues. The 1/4" phenolic spacers I added later did though. It should be noted that once dry (maybe a 2 days for thicker pieces) it does sand easily. When I remade the junction cover I was much less worried about molding it to the shape and instead just sanded it to the shape once dry. It was messy to do it this way but overall product was better looking and more consistent.
 
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