Heater core inlet/outlet?

[pickly]

anyone know which is the inlet or outlet on the heater core? I have a F-100 1972 390 and i'm not getting any heat through the heater core. I think i might have the hoses inverted. Right now I have the hose that has the control cable valve on the right and the hose that comes from the water pump on the left (looking under the hood at the firewall in front of the truck). Are these supposed to be the other way? The core has been flushed out and I replaced all of the fan components earlier this year.

[HOWDY69]

My valve is on the right when standing in front of the truck looking at the firewall.

[HOWDY69]

Is your valve working? Maybe the cable is the problem.

[fordman]

the core flows either way. it is the enigne hoses and valves that have to be on the correct way. also some valves dont operate the same as for our trucks. they are backwards. so you have to have the correct valve for your truck. here is a pic of a orginal truck to see where the hoses go to. http://www.fordification.com/images/70explpics/15.jpg

[Ranchero50]

Are the hoses getting hot? Flow doesn't really care. You can squeeze the bypas hose off and all the flow will go through the heater core. if the hoses aren't getting hot then you either have no water flow through the core, or engine isn't getting warm (is the top radiator hose getting hot?). For the no flow make sure the lines are connected correctly

One thing that I found out works rediculously well is Ford put flow restrictors in the '80's mustangs to slow the flow of cold coolant through the engine so it'll warm up quicker (for emmisions). They also did it to reduce the pressure spikes going into the heater core, thus saving the cores (or so I've heard). On my '93 I had removed the restrictor years ago when doing a hose replacement and after swapping in a good radiator cap for one with the rubber dry rotted both the radiator and heater core sprung leaks. I made a new restrictor out of nylon and drilled a 3/8" hole in it, yep 3/8". Now the heater is blowing warm air within 5 minutes of running. With the thermostat closed all the coolant goes through the heater. With the flow restricted the BTU's from combustion transfer into the coolant faster and the hotter the coolant the more BTU's you get to the heater. Same as a boiler setup in a house. The water cirulating pump only runs when the water at the boiler is up to temp (190` or so).

Another thing I found is I used to drill a 1/8" burp hole in the flange of the thermostat (which should be a 195` one for winter) and that little hole would keep the car from heating up quickly. It used to be fifteen minutes of running before the heater would blow hot. Now in 20` weather it's five minutes from startup, great.

Jamie

[basketcase0302]

Jamie,

Another thing I found is I used to drill a 1/8" burp hole in the flange of the thermostat

Seems like I remember getting t-stats in the 70's that had this hole drilled in them?

Man, the picture above of that blue truck is awesome! Is it a member here's truck?