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1980 720 heat shield


Veraciousreasoning

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Hey all,

 

Haven't been online much lately. Been working on the truck and preparing for the spring. During my truck journey I noticed that my heat shield vibrates like crazy and when you drive all you can hear is it shaking. I am curious if I can take it off or how I would go about fixing it. The heat shield and the screws are basically just a bin of rust. I tried tighting the screws down further and it just spins in a circle. I'd like to take it off but don't wanna overheat anything around it but I've seen later models without the heatshield. Any thoughts?

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http://static.carpartsmanual.com/datsun/pickup-1972-1979/large/620-038K-01.jpg

 

Part 44???? If in Idaho you should get the ATC (air temp control) working or keep it working. Wrap stove pipe wire around it to hold it to the manifold and stop the rattle.

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11 minutes ago, datzenmike said:

http://static.carpartsmanual.com/datsun/pickup-1972-1979/large/620-038K-01.jpg

 

Part 44???? If in Idaho you should get the ATC (air temp control) working or keep it working. Wrap stove pipe wire around it to hold it to the manifold and stop the rattle.

 

Yes part 44. It rattles like crazy and the screws are still attached. I tried tightening them and take them out and the screw just spins 

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Yes high heat area accelerates rusting. Tie in place with black stove pipe wire. You need a 'stove pipe' or metallic hose between the heat shield and the snorkel on the air filter housing. I cut open a Maxwellhouse coffee can and used it wired to the exhaust.

 

The ATC uses a vacuum operated motor and the temperature sensor in the air filter housing. By regulating the flap gate in the snorkel, hot air from the exhaust is mixed with ambient air from in front of the radiator and maintained at about body temperature. Even at -10 the engine will run like it's the middle of June. Because it uses manifold vacuum, when the throttle is floored the vacuum drops and the hot air is blocked to maximize power. The best thing is the warm air cannot condense and freeze moisture onto the venturi and cause carburetor icing.

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On 1/13/2022 at 5:56 PM, datzenmike said:

 

 

Yes high heat area accelerates rusting. Tie in place with black stove pipe wire. You need a 'stove pipe' or metallic hose between the heat shield and the snorkel on the air filter housing. I cut open a Maxwellhouse coffee can and used it wired to the exhaust.

 

The ATC uses a vacuum operated motor and the temperature sensor in the air filter housing. By regulating the flap gate in the snorkel, hot air from the exhaust is mixed with ambient air from in front of the radiator and maintained at about body temperature. Even at -10 the engine will run like it's the middle of June. Because it uses manifold vacuum, when the throttle is floored the vacuum drops and the hot air is blocked to maximize power. The best thing is the warm air cannot condense and freeze moisture onto the venturi and cause carburetor icing.

 

Hmmmm maybe that is why my car idle's roughly in the morning when it is cold. I don't have a snorkel coming off the manifold 

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The stock ones are metalized and can expand/contract like an accordion. Use hose clamps.

 

Carburetor icing happens when the ambient air is near and below freezing and the humidity is high. Gasoline absorbs heat when it vaporizes and can make the venturi super chilled below freezing. Humidity in the air will plate onto the venturi just like frost in a freezer even if the engine is fully warmed up. Eventually the venturi shape is restricted and the carburetor reduces the amount of gas drawn in and the mixture becomes very lean to the point you can't drive it. It will idle, as it is on it's own circuit, but you can't drive off. If you wait a few minutes the ice will melt and you can drive but it starts again after a few blocks. I find it happens most when there is snow on the ground but it is foggy or at or near zero and freezing rain. If you have ever experienced this the prevention is having a proper ATC (air temperature control) system working. Engines with a Weber won't have the stock air filter and thus won't have an ATC. There are a couple of posts on modifying the stock air filter to fit the Weber.

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