Radiator plug

[IanIrving]

Just pulled the radiator on my BJ8 today to install an electric fan and see that on the underside of the header tank there is a screwed in plug, looks to take about a 3/4 spanner. What was it for? I'm thinking I might be able to use it for the temp sensor for the fan if there's an adaptor of some sort.

Ian

 

[Patrick67BJ8]

Just pulled the radiator on my BJ8 today to install an electric fan and see that on the underside of the header tank there is a screwed in plug, looks to take about a 3/4 spanner. What was it for? I'm thinking I might be able to use it for the temp sensor for the fan if there's an adaptor of some sort.

Ian

Is it the drain plug or another plug? I believe you want the temp probe near the top of the radiator and not the bottom because the water temp will be cooler at the bottom. Mine is through the fins just below the tank.
Patrick

 

[IanIrving]

Hi Patrick
It's on the underside of the header tank so at the top of the radiator.
Ian

 

[Bob_Spidell]

The AH 100s had their temperature gauge 'senders' installed in the radiator top tank. I haven't looked at our BN2's radiator lately so I don't recall if the sender is on the underside of the tank. The radiator in the 6-cyl cars was possibly used on other cars that had the sender in the radiator tank, but since the sender was in the head in the 6-cyl AHs they just plugged the hole. This is conjecture on my part, but I believe it's reasonable.

IMO, it's a perfect location for a supplemental fan temp sensor (if you can find one that will fit).

 

[Keoke]

IMO, it's a perfect location for a supplemental fan temp sensor (if you can find one that will fit------

 

[IanIrving]

I agree, anyone know of a suitable sensor to switch the fan?
Ian

 

[BigGreen]

I have seen a top piece on the cylinder head that was taken from a Ford Fiesta (Europe) and had the switch in it.
Best picture I have;

Hans

 

[Randy Forbes]

My 100/6 has its temperature sensing bulb in the header tank. Not sure when it was switched, but most, if not all, of the 3000s I've seen have the bulb in the front of the head, near the thermostat outlet.

I expect that <span style="font-style: italic">the Healeys </span>discovered they'd get a more representitive reading from the water exiting the cylinder head, versus the water in the header tank...

 

[John Turney]

The sensor was originally in the radiator header tank on 100-6s. When they decided at some point (maybe when they went to the new head with separate intake manifold) they probably just plugged that hole.

I would guess the plug is soldered in place now.

 

[Keoke]

I would guess the plug is soldered in place now.

No it has a screwed on cap.--

 

[Randy Forbes]

The sensor was originally in the radiator header tank on 100-6s. When they decided at some point (maybe when they went to the new head with separate intake manifold) they probably just plugged that hole.

I would guess the plug is soldered in place now.

Nope, the 100/6 Mille Miglia still had the sensing bulb in the header tank. I'm thinking perhaps it was changed when they went with the electric (choke) auxilary carb.

Even on the latest BJ8 radiators, the cap (actually) can still be unscrewed.