question on radiator connections

[kikkegek]

got a question on my radiator.

I think it is still the stock radiator that came from the factory.

But why is the heater return hose connected to the high connection on the radiator left side?

The waterpump suck the water from the bottom right?

is this left side of the radiator open from top to bottom? so it serves as a collector?

dont mind the T-piece in the heater return. It is for the evaporator of my LPG system...

[ray_mcavoy]

Hi kikkegek,

Yes, both sides of the radiator are open "tanks". Hot coolant from the engine flows into the driver side tank, cools off as it goes through the radiator core, and gets drawn into the water pump through the hose connected on the lower passenger side.

Some hot coolant also flows out of the engine through the heater hose connected to the intake manifold. It cools off as it goes through the core and gets returned to the radiator through the hose connection in your pic.

Some setups had that heater return hose connected to a fitting on the water pump instead of the radiator.

I believe it was mostly trucks equipped with automatic transmissions that had the heater hose connected into the radiator like that. The trans cooler is in that side of the radiator so it was probably plumbed like that to keep a constant flow of coolant around the trans cooler (via the heater core which is always flowing even when the thermostat is closed).

[kikkegek]

hi ray_mcavoy

thanks for the reply. Is the trans cooler the two small lines going into the radiator? I am asking because while fitting my car with an electric fan I noticed I have three radiators on my car:

- one for the engine cooling
- a thing big one in front of that
- and a small one on the driverside in front of that one only about 8-10 inches wide
- AND there are these two thin lines going into my engine radiator...

if I can, I'll make some pictures of them today.

I tried following the lines:
- the small one seems to run under the car to where the oil filter sits and then enters the engine.


- the big one in front of my engine radiator connects to the A/C.

- and then there are these two small lines running into the engine radiator. So I guess these are the tranny cooler lines.

But what is the small radiator for then?

[James McClure]

tranny cooler lines are on the right side of the radiator and are steel about 5|16" diameter. teh lines on the left side of the radiator are eng oil cooler lines, aluminum and about 1|2" diameter. Aluminum lines going out in front of the radiator are A\C lines to the condensor. jim

[kikkegek]

Originally Posted by James McClure

tranny cooler lines are on the right side of the radiator and are steel about 5|16" diameter. teh lines on the left side of the radiator are eng oil cooler lines, aluminum and about 1|2" diameter. Aluminum lines going out in front of the radiator are A\C lines to the condensor. jim

thanks man!

I am afraid my engine is warming up too slow, because for my LPG system I have a evaporator connected parallel to the heater core. Because of this water is constantly circulating through the passenger-tank of the radiator and causing unnecessary cooling. I was afraid that moving the heater return to the waterpump would cause the tranny-cooler to run hot,because of the lack of circulation. I just learned that these two lines in the radiator are only for warming up the tranny fluid more quickly and not for cooling. Correct?

[James McClure]

Kik. Well, in certaain aspects your right, in others wrong. So, lets try to get the proper info to you. First, instead of supplying hot water to the LPG evaporator in parallel (this would cut available hot water to each roughly in half) install the evaporator in series with the heater core, with the evaporator first to get water. This will reduce efficiency of the heater somewhat but will make the evaporator work better. Also you might want to get a 195 degree thermostat. Next, Tranny cooler lines are just that, cooler lines they aren't to warm the fluid faster. jim

[kikkegek]

HI JAMES,
already got the 195F thermostat.
and putting the evaporator in series, would cut off the flow when heater is not bering used? or is there always flow over the heater core?

can you please explain your point on the trany cooler lines? are they? or are they not for warming up the tranny oil faster? what is their purpose?

I am now thinking about moving the return hose connection of the heater from the radiator to the return connection on the waterpump? this would make certain NO water flows over the radiator, warming up the engine as fast as possible to operating temperature, thus improving mileage...

But I wonder if this will cause problems with the tranny cooler lines? since the water wil then only flow through the radiator when the thermostat opens...

[James McClure]

Kik. There is always water flow thru the heater core UNLESS you have A\C. If you have A/C there is a valve that shuts hot water off. Tranny cooler lines are to cool the trans fluid and thats all they are for so forget about them. They will also function as per spec no matter where heater outlet is, in the radiator or the water pump. Also, no matter where the heater outlet is, water will flow thru the radiator. The rate at which the water flows is just a little faster if it's hooked up to the pump because there is a little suction at that location. jim

[kikkegek]

Hi Jim,
I do have A/C.

So hooking up the heater return hose to the pump would make sure there is no circulation through the radiator, unless the thermostat opens?

Cause thats how I would like it...that way the engine warms up as quickly as possible to operating temperature

[James McClure]

Kik. No, hooking the hose to the water pump will not decrease water flow. Read my above reply slowly one step at a time. You have A\C so there is a valve to shut flow of hot water thru heater core when temp on the heater is set to cold. This is to make the A\C operate better. It will also stop water flow over the propane evaporator. I would do this. Seeing as you have A\c leave the evaporator hooked up in parallel as it is now. Don't change the hose positions from radiator to the water pump. Leave the heater control set to cold. This will shut the valve greatly reducing water flow. It will not stop the flow entirely, but warm up will be faster. Still when the eng is cold evaporation will suffer no matter what you do. To bad you don't have TBI. GM's light trucks were available with propane fuel as an option and the TBI unit did all the work for you except high pressure propane regulation which was done back at the fuel tanks. With a little plumbing you can feed a TBI propane instead of gas or run a duel fuel setup. jim