Coolant port locations

[nutt7]

I am installing an electric fan switch; on at 210, off at 195ish. I need to tap it in somewhere. I am using the drivers side head for my gauge and the plug simply isn't coming out of the passenger head (which was the planned location). I don't know how confident I feel about using a t-tap either since neither sensor would be directly in the coolant flow.

What about the port on top of the water pump? Would that be an accurate temp reading location? I am not sure about the direction of water flow in this system...does water go out of the t-stat housing and into the top of the radiator, or vise versa? Are there any other taps in the manifold or anything? Tap into heater hose?

I picked my sensor on the warmer side of an 'on' temp, so I don't think I want to put it somewhere that will be much cooler than the heads if possible.

Thank you.

 

[76zimmer]

out of the Tstat into the radiator. Is there a port on the intake?
The water pump draws cooler water from the radiator, so that wouldn't be a good spot.
a little more info on the engine, manifold your using would be helpful!

 

[nutt7]

350 tbi, all stock

 

[nutt7]

Also, I saw a hex plug on the manifold, driver/front corner of the tb...just wasn't sure if it taps into air or a coolant passage.

 

[sweetk30]

coolent only goes left to right . not around the intake.

and put some heat on the plug in the pass side head. its all cast iron it will take it. also get a good breaker bar. and put some a$$ in to it it will crack loose .

 

[nutt7]

coolent only goes left to right . not around the intake.

and put some heat on the plug in the pass side head. its all cast iron it will take it. also get a good breaker bar. and put some a$$ in to it it will crack loose .

I went and bought a 5/16 square driver to remove it and it felt a little loose in there (it was fully seated). I began applying torque and felt it rounding out so I stopped. I had a bad experience of ripping a chuck out of an aluminum head while trying to extract a sender so I hope you understand my reluctance to continue. I also read about another person heating it up and ended up putting a small crack in the head so it leaked.

What do you think about removing the threaded manifold-to-heater hose and putting a tee there? Coolant should be the same temp there as is in the head, right?

 

[sweetk30]

i would first remove the quick coupler and ditch it thay tend to leak at this old age anyways.

then yes a tee in there would do .

and or if intake is off have someone tig weld on a block of aluminum in the driverside area of same spot and drill / tap it to take the sender.

but you realy want the coolent fan switch to hit on/off were the t-stat is closest . the back of the motor tends to be a tad bit hotter than the front if i recall.

 

[nutt7]

i would first remove the quick coupler and ditch it thay tend to leak at this old age anyways.

I was wondering what the extra fitting was all about...I plan to remove all of it.

but you realy want the coolent fan switch to hit on/off were the t-stat is closest . the back of the motor tends to be a tad bit hotter than the front if i recall.

This is fine with me, I just hope the fans won't continuously run. If so, I guess I can trade the coolant switch with the computer sender at the water neck.

 

[Mkuhn138]

Can't you tee off of the manifold where the temp sensing switch is (black and yellow wires)?

 

[nutt7]

I can, but I would prefer not to because it will probably be slower to react to temperature changes since neither sensor is in the flow of coolant, but rather in a little pocket.

 

[496truck]

At the advice of a man we call Fordum, I placed my fan switch in the water pump port. It's been working great in that location. Something about the volume of liquid in the system made the temp difference from the hot side to the cold side was negligible. Put it in the water pump port, it'll be fine.

You could also move the ECM temp sensor from the intake to the w/p port and run the fan switch from the intake port. I did this too with no change in the fan operation just a bit of tension on the wires for the sensor so I switched them back.

 

[nutt7]

I wish I heard that before I created my little contraption.

It works, but the five inches of brass sticking out of the manifold makes me a bit nervous. Maybe I'll switch it out, it'll only take 15 minutes...