Stock Cold air intake performance upgrades

[Ricko1966]

1967 Oldsmobile Turnpike Cruiser. 20 MPG 400 CID Cutlass.Electronic ignition,Temperature controlled air cleaner,highway gears. Check out that distributor and air cleaner, looks kinda familiar,doesn't it?

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[gmbellew]

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this is from the 1980 manual, i notice the thermac section is not as detailed in the 1980, and doesnt contain a delay valve. i bet the consistent 100 degrees was an evolved principal over the original use, because they realized they could get it to consistently deliver 100 degree air, so added that component as is noted in the 1987 manual below:

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it's hard to imagine underhood temps and heat soak into the thermac doesn't keep it in "fresh air delivery" mode after the engine is up to temp (135 deg f underhood air temp). it seems to me that the system is meant to warm up the engine faster for emissions and, in circumstances when driving in extreme cold, prevent the throttle blades from icing. otherwise I'd expect that it brings in fresh air after the engine is up to temp.

a more sophisticated system with a temperature sensor and a computer controlled flap, coupled with more elaborate sources of heated and outside air, may have more impact on regulating air intake temperatures. but I dont think the thermac system is that complex and the operating principles aren't sophisticated enough.

 

[Turbo4whl]

In case of a backfire the paper air cleaner doesn't catch fire and burn the fuel in the carb,and so on and so on. Didn't use to be uncommon for a car to burn to the ground from an air cleaner fire. Yes it's a 1 in a million thing,but 100s of millions of cars used to run around with carbureators and paper filters.

This is the reason as Rick stated. How it works, it actually helps to prevent back fire also. The Trapped vacuum spark system on the engine made for a lot of advanced timing when cold. That can cause back fire spark. The element has charcoal which holds the extra fuel that might back fire. When the engine warms up the saved fuel is gone for the next cold start.

 

[AuroraGirl]

it's hard to imagine underhood temps and heat soak into the thermac doesn't keep it in "fresh air delivery" mode after the engine is up to temp (135 deg f underhood air temp). it seems to me that the system is meant to warm up the engine faster for emissions and, in circumstances when driving in extreme cold, prevent the throttle blades from icing. otherwise I'd expect that it brings in fresh air after the engine is up to temp.

a more sophisticated system with a temperature sensor and a computer controlled flap, coupled with more elaborate sources of heated and outside air, may have more impact on regulating air intake temperatures. but I dont think the thermac system is that complex and the operating principles aren't sophisticated enough.

while moving the environment under hood will change and exchange a lot different than still or slow, but i suspect that the 80+ air dam is probably a big part of this
could be wrong

but it makes no sense to give the thermac a variable opening ,delayed valves, if it was just hot-or-not actuation

but then again, we also had quite complex vacuum actuated contraptions relying on multiple things like temperature vacuum switches, specific source vacuum, delay valves, 300 vacuum lines, and distribution blocks .. to create things like temperature-dependent vacuum advance behavior or encourage fuel vaporization quicker.. not out of the realm of reality what you say really lol.

eh, oh well lol