On my truck I have an air filter housing that has a piece that runs from the air filter to apiece that is around the exhaust manifold. What does this do, heat the air so that on cold days it will run better? And would it be safe for me to change to an open air filter for better breathing? And if I do this is it ok to just plug up the hose that goes from the valve cover to the filter housing.
thanks
brad

 

Brad; The sheet metal for heating the air intake is called the stove. It is there to do just what you said it does, to heat the air for better performance while cold. I do not recommend you remove it.
Inside the air cleaner is a thermostatically controlled mechnical flapper which is heat activated, and closes off the stove air once the engine warms up. You can test it with a hair dryer. The test works best on a warm day, but with the engine "cold", not having been run for 24 hours or so. Hold the air cleaner in it's natural position (a bench is fine), and blow hot air up the stove pipe entrance. The flapper should close soon.
The other hose from the air cleaner to the valve cover is actually a supply hose for the PCV valve on the other side of the engine. The PCV system hose sucks up unburned gasses from the inside of the engine, and sends them to the intake system, to be burned. The hose from the air cleaner to the valve cover supplies clean, filtered air for this cycle to work. Usually, though, when engines start to wear out, the amount of blow-by is greater than the PCV system can handle, and it starts to blow back through the supply hose.
In any case, don't plug that hose. You need it either for air to get into the engine, or for a way for the extra pressure to escape.

 

John is right, but if you live someware that is warm year round you can get rid of the heating tube. If this is the case I would tie the shutter door open to get more air at start up.

 

However... I live in Tucson, AZ which has pretty mild winters. My truck (352 2bbl) doesn't have a stove and it misses it on those cold (I know it's not REALLY cold) days before it warms up. I have a K&N filter and headers so I'm thinking about adding one of those after-market jobs.
jor

 

What is an open air filter?
Joe Herman

 

Also some states require the stove to be installed to pass inspection. I live in NC and have an inspection license and I have to fail a vehicle that does not have it hooked up if it came from the factory regardless of year. It has to have all the factory emissions equipment installed to pass a safety inspection and 75 model and newer has to pass emissions. I'm glad I have a 70

 

Hey Joe-

An open air cleaner is an aftermarket air cleaner. The most common examples are the chrome ones you can buy at most any parts store that have a base and top. You can see the element all the way around.

Joe

 

Joe
Thanks, now I know what it means. I kind of did that by putting a taller air filter than my air filter housing in my air filter housing. I have a 1972 F250 but I replace the oil bath air filter with a housing for a paper element from a later model Ford car.
Joe Herman


>Hey Joe-
>
>An open air cleaner is an aftermarket air cleaner. The most
>common examples are the chrome ones you can buy at most any
>parts store that have a base and top. You can see the
>element all the way around.
>
>Joe

 

Does anyone know where I can find a new or used filter housing for my '76 300 inline 6? I haven't been able to pass inspection because the thermostatically controlled mechnical flapper isn't functioning properly It's really a pain cause it's my daily driver and I can't drive it until I get the housing fixed, does anyone have any advice? I posted a want ad about this but I haven't had any responses. I hope it's ok to ask for help like this on this mb.