Bypassed my Heater Core yesterday.

[72step]

I recently installed a new Quick Fuel Carb recently on my truck. It's a Holley-type carb double pumper, and my heater hose went in to the intake right where my fuel line was so the heater hose was kinda streched because I kinda re-routed itl Anyway to make a long story short yesterday I had the truck idling while I adjusted the floats and there goes the heater hose, anti-freeze all over the place. Being that I still hadn't figured out a correct way to re route this heater hose, I yanked them both off, and plugged the holes on the intake and water pump as I never use this truck in cold weather anyway, and it looks way cleaner in my engine bay right now. Now I'm getting thoughts of just tossing the whole heater/ac unit and cleaning up the fire wall and if I ever decide I need it, I'll just purchase a vintage air and heat under dash kit as my a/c is not connected, not do I have the parts to connect it. What experiences does everyone else have with getting rid of the stock heat/ac unit. Thanks.

[oldschooler]

just plugging the holes is not by-passing your heater core. You need to connect heater hoses from engine in a loop, so that the water pump can still work.

[72step]

As long as the radiator hoses are still going to the radiator, how is it not working? The holes I plugged are for heater hoses which is an accessory.

[68C15]

I wouldnt worry. there is a bypass in the lower portion of the pass. side of waterpump. (the extra hole between the pump and block)

[oldschooler]

The top big rad. hose goes from intake to rad. bottom big hose goes from rad. to the inlet side of the water pump, the smaller outlet hose from water pump goes to heater core, the other smaller hose goes from heater core back to the intake. You could take small outlet hose from water pump and hook it to where the other hose from heater core goes into the intake. If you just plug the outlet hole from water pump, it will not have a way to get through the motor. I hope I didnt confuse the hell out of you

[oldschooler]

sorry!!!!!!! I didnt know they had a built in by-pass. Never realized thats what that other hole was for. Thats why I love this site. You learn something new everyday

[72step]

Wait a minute! If I plug the intake heater hole the water won't circulate?! So if the upper large radiator hose goes to the intake and the large lower radiator hose goes to the water pump, where are you blocking the circulation?
While we're on topic, does anyone have any ideas on how to plumb the heater hoses when using a double pumper carb with the long fuel line? Thanks again.

[wibilly]

how about plumbing it to the cylender head. you should have a pluged temp sending unit hole at the pas side head

[sodak69c10]

hey here is how i routed my fuel lines i ended up breaking my heater core when i was doing my swap so for temporary fix this is a shot of my by pass and my fuel line i have 6AN fittings on fuel system the i put a 90* fitting to run my fuel line over valve cover to clear hoses and keep fuel cooler

[70C10Toejam]

I run 2 ball-valves on my heater core, started with one to kill the heat in summer, and added second in case (and then happened) the heater core leaked. Have no problems in the summer.

If it would not circulate, how could the factory put shutoffs on trucks with A/C????? THe heater core should just siphon some coolant off, not afffect overall flow.

[GREASEMONKEY72]

you dont need the heater hoses on the pump, you can just plug them and be fine

[76bonanza]

72step here is a link to pics of my quick fuel carb and lines.

http://67-72chevytrucks.com/vboard/s...d.php?t=236167

[72step]

Thanks all for the pics and info. I think the first pic with the 90degree fuel fitting routing it towards the right is a good choice.

[68 P.O.S.]

I plugged the heater holes on my h20 pump as well and have never had any problems. It doesn't over/under heat and it runs fine.

[BigSky71]

This brings up a question for me, I shaved my heater core in anticipation of installing an aftermarket unit sometime later. For my heater hoses I just connected the water pump directly to the small outlet on the passenger side of the radiator. So will this circulate coolant at all or should I plug both ends of this connection?

[67chevemall]

I plugged them both with no problems....

[sean1969c10]

Double Pump Carburetors tend to be more race oriented, most race cars don't have heaters so it isn't an issue. This is not to say that you can't use a double pumper on the street, but if you have an engine that can really use what that carburetor is able to deliver, you probably won't use it in weather that would require a heater. It's also best to try to avoid using 90 degree fittings as much as possible, they reduce flow. Even two 45's are better than one 90. Just my 2 cents!

[Andy4639]

Originally Posted by BigSky71

This brings up a question for me, I shaved my heater core in anticipation of installing an aftermarket unit sometime later. For my heater hoses I just connected the water pump directly to the small outlet on the passenger side of the radiator. So will this circulate coolant at all or should I plug both ends of this connection?

You just made a loop is all. It want hurt anything it's just not really serving a pupose except to keep the system closed off. It would be a cleaner look if the hose was gone though I think.
You need to hook a over flow tank to the small connection on the radator for when it's hot. That is the purpose of the connection to begin with.