unscrewing plus at the end of heads

[forestb]

I have a small block 350 and I want to put the thermostat for my electric fan in the hole at the end of my head. Because I am told that that will give me the most accurate engine temperature. The problem I am having right now is that I have a thermostat for my electric fan that is supposed to turn on at 180 degrees and according to the thermostat for my gauge it is not turning on until it his around 220 degrees. The one for my gauge is in the front of my aluminum intake manifold and the one for my fan is in the rear. I have been told that the rear of the manifold is not a vary accurate place for a thermostat. My other option is a port in my intake manifold.

So I guess I have 3 questions.

1) do the ports seem like the problem?
2) what ports are the best to use?
3) If I use the port at the end of my head what kind wrench will work on the plug with the square hole? Allen wrench?

[Boom]

Are you measuring the temp with a temp gun? I would install the sensor in the front near the thermostat as it will give you the temperature of the water when it's leaving the engine.
As for the square plug I would use a ratchet to unscrew them. An Allen is used for Allen plugs.

[forestb]

Thanks for your help. I do not have a temp gun. I don't need one vary often so I am trying to avoid buying one. The only other port I have in the front of my engine near the thermostat is one that goes into the water neck. Should I use that? Or the port in the head?

How can I use a ratchet on a square hole? If it seams like I am trying to be difficult I am not. I am just not that knowledgeable.

[forestb]

If I remember correctly it looks something like this but I will take another look to make sure.

[Marshy]

I used the port in my passenger side head for my temp.

[forestb]

Was that in the front or rear?

Originally Posted by Marshy

I used the port in my passenger side head for my temp.

[Marshy]

Originally Posted by forestb

Was that in the front or rear?

On the passenger side between cylinders 5 and 7. I can take a pic later and post it. That way I don't have to see the ugly wire across the top of the engine.

[forestb]

no need for a photo I know where you mean. Thanks.

Originally Posted by Marshy

On the passenger side between cylinders 5 and 7. I can take a pic later and post it. That way I don't have to see the ugly wire across the top of the engine.

[Marshy]

These are Vortec heads so I'm unsure if your heads are the same or not but the same hole exists between cylinders 5/7 and 6/8.

See the brass under the plug wires?


Here it is between # 6/8 cylinders.

[storm9c1]

Yep, port in the heads are good, but for an electric fan switch at 180 degrees, I'd prefer an intake port. Fans may run too much in the head port. I'd move the gauge to the head port and the fan switch to the intake port if you can. I prefer a gauge on the head port because it will let you know MUCH sooner if you are about to overheat. I like having an earlier warning.

For the thread sizes on the head ports:
Vortec heads: 3/8" NPT
Older 60's/70s heads: 1/2" NPT

For clarification regarding the square plug, you want to use the 3/8" drive of the ratchet (or extension) with no socket attached. The square drive should fit right into the plug.

[rocknss]

I have mine installed in the intake manifold by the thermostat. Here is a pic.

[forestb]

Thanks everyone.