BBC in a 34 Pontiac. Im trouble shooting the heat. Found the vacuum lines under the dash not hooked to the hot water valve. Took care of that and still no heat so I went under the hood. The previous owner has the heater hoses running to the water pump through the heater core and then pulling water from the RADIATOR! not the intake. Looks like a custom radiator with the heater hose connected to it. I can't imagine this will work, i ***ume it will draw just hot air as the connection level is very high on the radiator. Anyone ever seen this type of hook up? If so does it work? I can only get room temp air at idle.
That won't work. But you need to post a few pictures, so we can see what's going on. There should be a threaded hole for a pipe fitting on the front of the intake manifold, that's where the heater would get hot water from. the pictures you post will tell the story
The radiator connection was used on a lot of Chevys in the 70s-80s, instead of connecting to the water pump. if you connect the heater to the water pump and the radiator, but not to the intake manifold or cylinder head, it won't ever make heat. Both connections are to different ends of the lower radiator hose. That's might be what's going on here.
My brother in-law pulled that move. 2 sources of coolant with no pump in between equals no flow. Intake = outlet from water pump Water pump = return Radiator = return
The 454 in my 77 C30 is set up with the hose running from the intake to the heater, then from the heater to the radiator and then the heater inlet on the water pump is plugged. What you need to do is pull the fitting out of the water pump and put a plug in it and pull the plug out of the intake and put a fitting it and you might be able to swap them around if sizes match. Hot water out of the intake by the thermostat housing, to heater, through heater, cooler water headed to the radiator where it mixes with the coolant in the radiator and heads to the water pump and repeat.
yes Jim, I'm sure that is the issue. The car was well built, and I was thinking they knew something I did not. Ill try to get pictures but it is as I described. Water pump, heater core, radiator. Nothing picking up heat from the engine....
Which side of the radiator is the heater connected to? The end that connects to the thermostat, or to the water pump?
Auto cooling 101, Any connection to the water pump is an inlet to the engine block connection with the water pump pulling coolant from either the radiator or the heater. Outlet would be near the thermostat or the top of the head like some of the later SBC that have the heater hose connecton at the back of the p***enger side (US or left hand drive) of the engine. A connecton to the radiator is a return from the heater to the radiator and then to the water pump.
In my scenario there is no exposure to engine heat. water is pulled from the top of the radiator, through the heater core and into the water pump through the typical BBC heater hose ******. Seems to me only minimal hot water and probably air is p***ing through the heater core via this set up. There is no heater hose attached to the head or intake anywhere. Just the loop as I described. The port in the intake where the heater hose would normally go is occupied for other reasons. Not heat.
WATER DOES NOT FREAKING GO FROM THE TOP OF THE RADIATOR TO THE HEATER. it flows from the heater to the radiator to the heater, learn something about cooling systems from those of us who have over a hundred years of combined experience working with these things rather than dreaming up freaking senarios. They hooked it up wrong and quit making excuses. Even if the pump were to pull coolant through the heater backwards from the radiator it would be coolant that had already cooled off some. I imagine that what ever street rodder hooked it up that way thought it would look cleaner hooked to the pump rather than the intake.
We all know its wrong. The question originally was does anyone know why this would be? After all its a quality build and perhaps someone may have an idea. I think you are correct perhaps it was simply a cleaner look not caring about heat. I appreciate your expertise, but you really should relax.
The first thing I would do would be to change the thermostat in the motor. The average life of a thermostat these days is between 2-5 years. A 195 degree thermostat will provide the warmest coolant to flow through the system (a 180 stat would be the lowest temp thermostat i would even consider using). The hotter thermostat sure makes a big difference in the heater temps when its cold outside. Before you put everything back together, keep reading. Then I would wonder about the flow of the coolant through the heater core. A partially plugged heater core will not allow enough coolant to p*** through to provide much heat. You are still getting water flow through the core, so maybe you should back flush the heater core to clean it out. The coolant flow in your system is from the radiator through the heater core and then to the water pump. To back flush the core, disconnect both heater core hoses and run garden hose pressure water through the core from the water pump hose through the core and discharge the water out of the radiator side of the core. Run the water until it comes out of the core clean. Then reconnect the heater core hoses to their proper location and top off the coolant level. I'm surprised you GM guys haven't figured out the the coolant temp at the top of the radiator is the hot coolant, its the same temp as the coolant from the intake is. As soon as the thermostat opens, the hot coolant goes directly into the upper radiator hose to p*** through the radiator. I'm told GM first introduced the hose connection in the radiator instead of in the intake manifold with the Chevy Monza.
Just tap in to Rear of Intake P.S. or in P.S. Rear on head in between 6&8 for "" Hot Water In "" into Heater core , then Return back to Radiator .. & Burp heater core . Or " Hot In " If enough room ( 3/4pip plug) the Backside End of head near @ firewall or even one of the freeze plugs On Block.. There is several ways Oem GM plumbed the heater core In & Out. Just Like # 1 on v8 distributor cap if you have been playing and working on GM's you will see that # 1 terminal is NOT always at the 5 o'clock position !!
I have some concerns over this. The "tap" location at the back of the intake should be a hot, high pressure point and would be OK as the inlet for the heater core. The ****** location on a radiator that has a ****** location is also a hot, high pressure point for the cooling system. If both hot, high pressure coolant ports are plumbed to the heater core, the coolant will not flow through the heater core. The opposing high pressures facing each other will stop or severely slow the coolant flow through the heater core and very little heat will be available to warm the vehicle. The heater core has to see a high volume of hot coolant flowing through it to have transferable heat. That coolant return from the heater core has to go to a lower temp, lower pressure point, before the coolant can flow. That lower temp and pressure point is the water pump. That water pump is ****ing the coolant through it and sending it back into the block. The guy already has a high temp, high pressure point at the radiator, and a low pressure point at the water pump. He has to fix coolant that is not hot enough, or he has to fix a restriction in the coolant flow through the heater core. Why make more work that is not going to accomplish anything?
@gene-koning Water pump still pulls water from Radator, So return from heater core To Radator the pump will pull & circulate.
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