[hcccs]

I have two ports on my Millennium cylinders and I don't know what they are for. One of them is obviously for the CHT probe but which one is it and what is the other one for?

 

[mahlon_r]

The CHT port is on the bottom of the cylinder head, in the middle, of the aluminum head portion of the cylinder between the spark plug port and the last aluminum fin toward to the crankcase. The two 1/8 pipe plugs in the picture are ports into the intake port that are used for Primmer or Fuel injection nozzle or a manifold temp fitting.
If you installed a temp probe in either depicted port, you would get Inlet air temp at the intake port not the cylinder head temp.
Good Luck,
Mahlon
?The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

 

[az_gila]

It's the hole just to the right of the green plastic plug in the bottom spark plug hole in this picture...

 

[RV10inOz]

The one in the inlet manifold is for a MP sensor.

 

[hcccs]

Manifold pressure port?

The CHT port is on the bottom of the cylinder head, in the middle, of the aluminum head portion of the cylinder between the spark plug port and the last aluminum fin toward to the crankcase. The two 1/8 pipe plugs in the picture are ports into the intake port that are used for Primmer or Fuel injection nozzle or a manifold temp fitting.
If you installed a temp probe in either depicted port, you would get Inlet air temp at the intake port not the cylinder head temp.
Good Luck,
Mahlon
?The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

Either of these ports are for Manifold Pressure and not Manifold Temp, right?

 

[Walt]

Either of these ports are for Manifold Pressure and not Manifold Temp, right?

That's correct, they are both MP but usually the lower hole is used for MP and the upper is used for fuel injection.

 

[aerhed]

That's correct, they are both MP but usually the lower hole is used for MP and the upper is used for fuel injection.

Lower hole is also used for primer nozzles on carbureted units.