TR6 Desired TR6 engine coolant temp?

[Norton47]

Still working through cooling system issues.
I have installed a 16 inch electric fan, I don't think it's that likely to fail and I want all the air flow I can get when at idle or in stop and go traffic. That's what I want, I will take the additional possible failure mode.
I have purchased a 160 degree thermostat.
My plan is to try both. While they are installed I want to measure the top and bottom of the radiator with the IR thermometer and see how well the radiator is cooling.
We are suppose to have some 70 degree days coming up so I will be trying this tonight or tomorrow.

Then be prepared to replace the radiator. I can't see how if it's clean and the fins are attached well to the tubes how these fall off in cooling efficiency? I suppose the join between the fins and the water tubes could become thermally blocked due to corrosion?

Anyway while doing some research, I was looking for what temperature range does the engine operate best at. The general info for this seems to be 200 degrees F and I saw a specific TR website that recommends 185 degrees F for TR6's.
Fairly close, based on this information, normal gauge operation should usually be between the first mark (~180 deg F) and the middle mark (~205 deg F) and rarely go above the middle mark.

Does this seem correct?

 

[poolboy]

We are in hitting 90 degrees down here right now; we won't see the 70's during the day until October.
So dealing with heat is half the year in the Deep South.
I always assumed that the needle should be on about the middle hash mark of our gauge. And, I have taken the Normal Operating Temperature to be in the high 180's.
I recently installed a 12 inch electric cooling fan with the 180 on--170 off T-stat switch and a manual overide switch in the cockpit.
If I start up and drive off when the temp.gauge needle starts to move, I get the same temp reading as the red fan gave me by letting the thermostatic switch control the fan.
But, if I just want to let the engine idle so I can do someting like adj. the carbs, I have to use the manual overide to get a head start on cooling before the hot water hits the radiator because I'm not getting air flow from the grill.
If you anticipate being stuck in traffic you might want that overide switch to be sure that the fan is on all the time not just in the range of the thermostatic switch.

 

[swift6]

I can't see how if it's clean and the fins are attached well to the tubes how these fall off in cooling efficiency? I suppose the join between the fins and the water tubes could become thermally blocked due to corrosion?

That is one of them. Another is that with internal corrosion, it is extremely difficult to get the insides totally clean. Nothing is cleaner than new.

Anyway while doing some research, I was looking for what temperature range does the engine operate best at. The general info for this seems to be 200 degrees F and I saw a specific TR website that recommends 185 degrees F for TR6's.
Fairly close, based on this information, normal gauge operation should usually be between the first mark (~180 deg F) and the middle mark (~205 deg F) and rarely go above the middle mark.

Does this seem correct?

Sounds about right.

 

[GreenOne]

Have you considered pullng the radiator and taking it to a radiator shop and having it cored and boiled. You may have some crud blocking some of the passages.

If the rad is in generally decent condition there is no reason to replace it.

 

[TR3driver]

Fairly close, based on this information, normal gauge operation should usually be between the first mark (~180 deg F) and the middle mark (~205 deg F) and rarely go above the middle mark.

Apologies if this has been beaten to death ... don't forget that the gauges are notoriously inaccurate. The ONLY way I would assume that the first mark corresponds to 180F is if I had calibrated it that way myself, using the sender installed on my engine.

Lots of vendors are now selling a "one size fits all" sender that is NOT the same as the original sender. This can be seen by the fact that there are about 6 different original Stanpart numbers that now all cross-reference to the same number !

 

[Brosky]

My electric fan kicks on when the gauge gets just over the 1/2 mark. From the reading on the digital thermal gauge, that would be about 186 degrees, which is pretty close to the 185 sensor switch that I have.

I also have a manual override just in case, but have yet to need it for tuning or anything else as the fan kicks on at 186.

So what does that mean as far as my original gauge calibration to the new sensor? I have no idea about it's accuracy, but it does not overheat, so that's all I care about.

However, I do agree with Randall and if I ever get a gauge rebuilt or recalibrated, it will be with the matching sender.

 

[Norton47]

TR3driver
I made these measurements for the sender and the gauge.
https://www.britishcarforum.com/bcforum/ubbthreads.php/topics/460596/Temperature_Reality#Post460596
Not the same as calibrating a sender and gauge, more of a characterization. Close enough for this job for now.

I ran the 180 degree thermostat last night with the 16 inch fan and took temps with a Fluke IR probe. I found that the sender housing ran from 174 degrees to 202 degrees, while the gauge was was indicating just below the center mark and at the 3/4 mark respectfully.

The radiator has about a 30 differential. The tank at the top was 174 degrees F and the bottom tank was 145 degrees F, with the fan running. Does this seem about right?

My thermostatic switch seems to have gone bad, I got it to change state at 177 degrees F in the test pan, but it won't close now and turn the fan on, so I used the override switch for this round of testing. I have to round up a replacement today.

 

[tom628]

I have a 185/170 sensor in the top tank of my radiator, with a new core.(original sprung a leak when the shop cleaned it). Also, a 160deg. thermostat.
Engine consistently runs just at the first mark (above the "base" mark) in the 70-80 deg. weather we've been having here. Fan has never come on except after several minutes of idling, when the needle approaches the 3rd mark.

Just as an aside, the lower engine temp. by changing from a 180 to 160 t.stat, the new core, and thoroughly flushing the block and heater eliminated a persistent highway-speed pinging I could not seem to get rid of within any reasonable timing range. I was even able to drop from premium to mid--grade fuel.

Tom