[BinderDriver]

I've never had to have one of these things. My cars have either been too old or too new. I've always been a pre-'68 kind of guy, unless I was involved with '88 and later Mustangs.

Now I've got a '71 Chevy and I'm told it needs an enclosed air cleaner with a temperature sensor and more moving parts than I'd like. But I'd like to make the best of it. It looks to me that something like the L82 dual snorkel air cleaner could be used to create some sort of ram-air effect.

I've been told, though, that they only allow fresh air in if the temperature is above 85dg.

That just doesn't seem right to me. I was under the impression that the flapper valve remains closed until the engine warms up, yes. But if the flapper valve keeps closing because the air temp is too low outside, that'd mean the car will run too rich in what amounts to normal weather from fall until spring.

Is it really true that on a cool day day the engine will be forced to intake air from the heat stove only, no matter how much you warm up the engine?

[DoubleVision]

The only cause for the stove pipe was to prevent carb icing in the winter months. Humidity in the high velocity air would form ice and stick to the carbs butterflies which would also plug up the idle circuit forcing the carb to draw fuel from the boosters resulting in a really rich mixture that causes fouled plugs due to flooding. If I recall vacuum switches operated the stove pipe flap and they are operated by engine coolant temp, not air temp.

[pepi]

Originally Posted by DoubleVision

The only cause for the stove pipe was to prevent carb icing in the winter months. Humidity in the high velocity air would form ice and stick to the carbs butterflies which would also plug up the idle circuit forcing the carb to draw fuel from the boosters resulting in a really rich mixture that causes fouled plugs due to flooding. If I recall vacuum switches operated the stove pipe flap and they are operated by engine coolant temp, not air temp.

That is a good one never knew that, was that a geographical option or standard issue.. ?
I was living in Fl in 71 .

[T-bucket23]

Originally Posted by DoubleVision

The only cause for the stove pipe was to prevent carb icing in the winter months. Humidity in the high velocity air would form ice and stick to the carbs butterflies which would also plug up the idle circuit forcing the carb to draw fuel from the boosters resulting in a really rich mixture that causes fouled plugs due to flooding. If I recall vacuum switches operated the stove pipe flap and they are operated by engine coolant temp, not air temp.

This is correct, most ran off the vacuum switch that was attached to the top of the thermostat housing. Outside air temp had nothing to do with the operation.

[KULTULZ]

Even the thermostatically controlled valves would work off exhaust manifold heat.

[sbchevfreak]

Chevy used a bi-metallic thermostat vacuum valve inside the air cleaner. It is adjustable to maintain a certain temperature inside the air cleaner. There is a spec, but I can't recall of the top of my squirrel brain. You can tell if yours has one by the vacuum hose routing. If there is a vac line to the side or underside of the air cleaner, and another from that same spot to the vacuum motor on the snorkel, you have the adjustable switch. If not, you have one like DV described.