OK to put temp senor in waterpump bypass line?

[Apex_speed]

Originally Posted by bingo2

No heater. The CTS is located in the passenger side port where the heater valve would be located and the sender for the analog temperature gauge is in the driver side port. I originally had them installed opposite of their current location but, I changed to more efficiently route the wiring; readings were identical from either location. If I did have a heater, I would try the tee in the driver side port and if it didn't function to my satisfaction I would drill and tap another port as others have suggested.

Ok, thanks.

I'm going the path of least resistance for now. Holley sender on the right side and gauge sender on the left side as the Edlebreock Performance RPM manifold is drilled correctly for that.

I think I will look into an extension for the t-stat housing that is threaded for a sender as that would likely work well. I'm just not sure if it's physically possible in an SPF Cobra with a 351W block and the surge tank mounted at the top front of the engine.

[Gaz64]

Is there no room in the front water crossover to add a temp sender?

I would drill a hole, tap it 1/8 npt, and fit the sender.
That way you can see the engine warming up on all gauges.
Adding a sender after the thermostat, the gauge will barely work at all, then rise up, showing the thermostat operation.
Unless you want to see it that way.

Gary

[cycleguy55]

Originally Posted by Apex_speed

Ok, how about we try this if you don't mind....where are the following located in your car?

1. Holley Sniper coolant temp sender?

2. Dash gauge coolant temp sender?

3. Heater return line?

BTW, the fitting on the intake manifold is the hot coolant to the heater, and the heater return goes to the water pump.

[Gaz64]

Originally Posted by cycleguy55

BTW, the fitting on the intake manifold is the hot coolant to the heater, and the heater return goes to the water pump.

If you must use a heater hose, this is correct.

Using the return hose would be like placing it in the bottom hose, as the return from the radiator.

[Apex_speed]

Ok, I think my problem is solved thanks to Craig's Cobras.

In the second diagram in the link below he shows alternate plumbing for the water pump bypass hose and heater. If I switch over to this, I should be able to put an inline tee fitting for the EFI's CTS in the now lengthen bypass line up be the manifold and have engine temp coolant flowing past it all the time.

I'm headed this route over drill a tap of my manifold unless anyone sees issues with it. There is just not much room on my manifold around the MSD distributor and the other sensors so it would turn out like a bit of a cluster.

Aluminum Head Thread Repair

[Apex_speed]

I came up with a better solution for the Roush 427R. There is an aluminum spacer block that holds t-stat housing 2" off the front of the motor. I am drilling and tapping that and putting a small weep hole in the t-stat.

[brad-cam]

Waking up this thread to ask as related question I have. I have a 347 with Edelbrock AirGap manifold and Holley Sniper. Temp gauge sender is on right (passenger) side coolant port, no heater loop connected. Sniper EFI coolant sensor is on left (drivers) side coolant port. At idle both the gauge and Holley CTS are reading the same temp, however when driving on a 60 degree day, the Holley CTS runs about 20 degrees cooler than the gauge. I have a 180 degree thermostat. The gauge moves between 180-190, but the Holley CTS reads 150-152 (which means not warm enough to activate learn mode).

Could this be because of airflow through the cylinder 5 intake runner and it's proximity to the coolant sensor port? Or proximity to the cool coolant coming back from the radiator?

I'm going to swap the sensors side-to-side to see if the Holley CTS goes up to 180.

I just replaced the CTS with a new GM one after dealing with the well known "bad CTS" issue with the Holley-supplied one.

Thank you in advance for any guidance you have !!

[spdbrake]

You can switch your thermostat housing to one that will accept a temp sensor.
90deg type:
Boss is there but you'll need to tap it for NPT.
https://www.summitracing.com/parts/f...-m90/make/ford

Ready to go.
https://www.summitracing.com/parts/mrg-9713/make/ford
https://www.summitracing.com/parts/r...1003/make/ford
https://www.summitracing.com/parts/sum-370980/make/ford
https://www.summitracing.com/parts/s...92-b/make/ford
45deg type:
https://www.summitracing.com/parts/r...1001/make/ford

[brad-cam]

Thanks, I might go that route. I need the 45deg type. I also don't have the coolant bypass connected (port on thermo housing is plugged), just the pin valve in the thermostat. I plan to add the bypass hose to the water pump port (as OEM). That might be unrelated to the side-to-side temp imbalance I am seeing, but I think it should be there.