Heat tube from exhaust manifold to air cleaner

[Kiqman]

Installed headers. I've looked through many posts trying to find the aftermarket set-up that will allow me to reconnect the tube that used to run from the stock exhaust manifold to the air cleaner housing. The posts with links seem to be expired. Can I just connect the aluminum hose at each end with hoseclamps? Will the air being sucked past the hot header function like the stock system? I'm not doing this for emissions - I want the vehicle to warm up faster and bog less when cold.

 

[randy88k5]

Yeah, if you can get the hose clamps on there, that would be fine. My setup didnt have clamps at all. Just pressure fit on.

I ditched that stuff a long time ago though.

 

[bronderslev]

that is alsow the only reason you shoud do it... cause whenn you put hot air in to the engine you getting a bad´r filling of your cylinders and there fore less power out of your engine.....

cold air = bigger densety = more efesenty

hot air = thinner densety = less efesenty

bronderslev
denmark

 

[HarryH3]

that is alsow the only reason you shoud do it... cause whenn you put hot air in to the engine you getting a bad´r filling of your cylinders and there fore less power out of your engine.....

cold air = bigger densety = more efesenty

hot air = thinner densety = less efesenty

bronderslev
denmark

The air intake system is configured with a thermostat. It only draws warm air from the heater tube when the incoming air is too cold, which can cause throttle body icing. One things are warm, it draws in outside cool air.

 

[beater_k20]

you wont notice any real difference in the way the engine warms up with or without this system. last winter, i lost the tube off of my 91 K1500, and didnt notice it was gone until the following spring i went to change the oil and replace the valve cover gaskets, removed the air cleaner to change the valvecover gaskets and it was gone.

 

[HarryH3]

If weather conditions are just right, you will most definitely notice when the engine stops running... I knew several people that had it happen to them when I lived in Massachusetts. When it was really cold and humid out, the engine would slowly lose power and finally stall, then they would pull off the side of the road. After just a few minutes, the engine would start right back up and run great.... for a few minutes.

The carb/throttle body throat would ice up until it stalled the engine. Once the cold air stopped getting sucked in, the heat from the engine would warm up the carb/throttle body and melt the ice. Then the cold, wet air would start coming in once again and the whole process would start over. I'd love to know how many vehicles have been sold as "unreliable in winter" because someone wouldn't spend $4 to replace the heat riser.

 

[bronderslev]

warming up intake air

I´m liveing in denmark a small contry way up north in europe and we are surrounded by sea, that does that in the fall winter and spring, the temperture is offen low and the humity is high at the same time, there fore its a known problem here

so yes harryH3 thats right is will do that and mostly from +7 deg C to -7 deg C when thet humity is high... you can over come this problem by adding isopropyl alkohol, mix ½ L iso to 3½ gallon of gas...

but by adding iso you wont get the carberator ice, because the iso bindes the H2O so it dosent fress and klog up the venturi in the carb...

but seen from a performens point, cold and humit air will give you the best filling of your cylinders and ther fore more power, as you can burn more fuel per ignition strok...

bronderslev

 

[bronderslev]

warming up intake air

I´m liveing in denmark a small contry way up north in europe and we are surrounded by sea, that does that in the fall winter and spring, the temperture is offen low and the humity is high at the same time, there fore its a known problem here

so yes harryH3 thats right is will do that and mostly from +7 deg C to -7 deg C when thet humity is high... you can over come this problem by adding isopropyl alkohol, mix ½ L iso to 3½ gallon of gas...

but by adding iso you wont get the carberator ice, because the iso bindes the H2O so it dosent fress and klog up the venturi in the carb...

but seen from a performens point, cold and humit air will give you the best filling of your cylinders and ther fore more power, as you can burn more fuel per ignition strok...

bronderslev

 

[hi pinion]

Did someone say MUFF?

 

[Kiqman]

There's no doubt that cool air is more powerfull. But I chased this cold bogging engine every winter since I put the headers on. I even switched to electric fans to help the engine warm up quicker. Last winter it was the same story. I always keep "HEET" in the system during the winter because it's so cold and very humid here in northern Oregon. I'm going to look into changing the coolant temp sensor since it was mentioned to me on this board. I'm also going to re-re-re-re-check for vaccum leaks. I tried to use WD-40 but I'm thinking I need something a little more flamable like starting fluid. Happy wrenching this weekend fellas!

 

[jekquistk5]

Mines been missing for 2 years, so Its not a big concern for me, and I'm going to long tubes

 

[Kiqman]

Ya, mine was missing on and off all the time before I rebuilt my motor. Right now I have the warm air intake in my air cleaner housing plugged in the "fresh" position. Another poster on here said that without the tube the ECM gets much colder air than it thinks it should be getting so it dumps fuel since it reads the condition as a "stall". This is of course before you go into closed loop. I don't know if I buy that logic...
In a stock setup the intake is taking in warmed air almost right after you start the motor which makes the O2 sensor start reading faster. When you add headers and delete the heat tube you slow the O2 sensor startup for two reasons...1) there's no heat tube feeding in warm air and...2) The O2 sensor usually has to be moved a little further downline to accommodate the header/collector. I almost think that a little cold with a lot of humidity is worse than a lot of cold with little humidity. With as much moisture as we get around here I could just have a little moisture in my dist cap at times.

 

[HarryH3]

To make the header end of a heat tube check out the exhaust adapters for something like a Honda at the parts store. I found one that the heat riser tube fits over perfectly. Just cut and flare the other end to fit over a header tube, leaving some room for air to get sucked in. A couple of hose clamps can hold it to the tube.